Search Results (3,335)

This study investigates the technological and chemical causes of early zinc-coating degradation on cold-formed steel sections produced from DX51D+Z140 galvanized coils. Commercially manufactured products exhibiting early corrosion symptoms were used in this study. The entire processing route, which included strip preparation, cold rolling, hot-dip galvanizing, passivation, multi-roll forming, storage, and transportation to customers, was analyzed with respect to the residual surface chemistry and process-related deviations that affect the coating integrity. Thirty-three specimens were examined using electromagnetic measurements of coating thickness. Statistical analysis based on the Cochran’s and Fisher’s criteria confirmed that the increased variability in zinc coating thickness is associated with a higher susceptibility to localized corrosion. Surface and chemical analysis revealed chloride contamination on the outer surface, absence of detectable Cr(VI) residues indicative of insufficient passivation, iron oxide inclusions beneath the zinc coating originating from the strip preparation, traces of organic emulsion residues impairing wetting and adhesion, and micro-defects related to deformation during roll forming. Early zinc coating degradation was shown to result from the cumulative action of multiple technological (surface damage during rolling, variation in the coating thickness) and environmental (moisture during storage and transportation) parameters. On the basis of the obtained results, a methodology was proposed to prevent steel product corrosion in industrial conditions. Full article

The development of deep eutectic solvents (DESs) is a key issue for the realization of green and efficient metal extraction processes. The present study aims to experimentally construct the phase diagram of the binary system consisting of tri-n-octylphosphine oxide (TOPO) and 4,4,4-trifluoro-1-phenyl-1,3-butanedione (HBTA) and, thus, determine its eutectic composition for the solvent extraction of Li⁺. Differential scanning calorimetry was used to characterize the phase transitions (melting temperatures and enthalpies) over the entire composition range of the binary mixture. Its eutectic composition was established at HBTA:TOPO mass ratio of 60:40. For further validation of the eutectic composition from the experimentally measured thermal effects for melting of different HBTA:TOPO mass ratios, a Tammann diagram was also constructed. Only mixtures with HBTA:TOPO mass ratios of 70:30, 60:40 (eutectic composition), and 50:50 were liquids at 30 °C, while at room temperature of 25 °C, the 70:30 mixture formed crystals. All three mixtures, which were liquids at 30 °C, were found to extract Li⁺ effectively. However, at a room temperature of 25 °C, only the eutectic mixture (60:40 mass ratio) extracted Li⁺ effectively, while the mixture with HBTA:TOPO mass ratio of 50:50 formed crystals when mechanically agitated and, therefore, was deemed as unsuitable for Li⁺ extraction. Full article

Nitrate pollution in groundwater poses severe threats to ecosystems and human health, making the electrochemical nitrate reduction reaction (NO₃RR) a promising remediation technology. Conductive metal–organic frameworks (cMOFs) with π-d conjugation, dispersed active sites, and tunable structures are ideal candidates for electrocatalysis. Herein, we synthesized a series of cMOFs (M₃(HHTP)₂, M = Fe, Zn, Cu, Co, Ni) via conjugated coordination between hexahydroxytriphenylene (HHTP) ligands and metal ions and systematically investigated their NO₃RR performance. Electrochemical tests revealed that Fe₃(HHTP)₂ exhibits superior catalytic performance for nitrate reduction, achieving a high NH₃ selectivity of 99.5% and a yield rate of 676.4 mg·g_cat⁻¹·h⁻¹ at −1.0 V vs. RHE (reversible hydrogen electrode), along with excellent cyclic and structural stability. In situ attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy identified key intermediates (*NO₂, *NH₂OH) and proposed the reaction pathway: NO₃⁻ → *NO₃ → *NO₂ → *NO → *NOH → *NH₂OH → *NH₂ → *NH₃. DFT calculations revealed that Fe center exhibited a lower energy barrier for NO₃RR compared to other metal ions (Zn, Cu, Co, Ni). This study demonstrates the significant potential of Fe₃(HHTP)₂ for efficient NO₃RR and provides new insights into the structure-function relationship of cMOF-based electrocatalysts. Full article

Nanotechnology is becoming a key tool in plant biotechnology, enabling nanoparticles (NPs) to deliver biomolecules with high precision and to enhance plant and tissue resilience under stress. However, the literature remains fragmented across genetic delivery, in vitro regeneration, stress mitigation, and germplasm cryopreservation, and it still lacks standardized, comparable protocols and robust long-term safety assessments—particularly for NP use in cryogenic workflows. This review critically integrates recent advances in NP-enabled (i) genetic engineering and transformation, (ii) tissue culture and regeneration, (iii) nanofertilization and abiotic stress mitigation, and (iv) cryopreservation of plant germplasm. Across these areas, the most consistent findings indicate that NPs can facilitate targeted transport of DNA, RNA, proteins, and regulatory complexes; modulate oxidative and osmotic stress responses; and improve regeneration performance in recalcitrant species. In cryopreservation, selected nanomaterials act as multifunctional cryoprotective adjuvants by suppressing oxidative injury, stabilizing cellular membranes, and improving post-thaw viability and regrowth of sensitive tissues. At the same time, NP outcomes are highly context-dependent, with efficacy governed by dose, size, and surface chemistry; formulation; plant genotype; and interactions with culture media or vitrification solutions. Evidence of potential phytotoxicity, persistence, and biosafety risks highlights the need for harmonized reporting, mechanistic studies on NP–cell interfaces, and evaluation of environmental fate. Expected outcomes of this review include a consolidated framework linking NP properties to biological endpoints, identification of design principles for application-specific NP selection, and a set of research priorities to accelerate the safe and reproducible translation of nanotechnology into sustainable plant biotechnology and long-term germplasm preservation. Full article

Corrosion in complex acid environments, such as high temperatures and acidic downhole conditions, remains a critical threat to well integrity during oil and gas acidizing. This review firstly examines the influence of downhole variables, including temperature, acidity, and steel, on the performance of organic inhibitors. It analyzes molecular design strategies that enhance the stability and adsorption of traditional inhibitor classes, including Mannich Bases, quaternary ammonium salts, and benzimidazoles, through structural modifications such as rigid heterocycles, extended alkyl chains, and multi-dentate architectures. The discussion extends to synergistic formulations, sustainable alternatives derived from biopolymers or green chemistry, and intelligent responsive systems. Furthermore, the growing role of computational methods, from molecular dynamics simulations to AI-driven molecular design, in accelerating the discovery of high-performance inhibitors is highlighted. Together, these advances offer a comprehensive and forward-looking perspective on developing adaptive, efficient, and environmentally compatible corrosion protection strategies for next-generation hydrocarbon extraction. Full article

Graphene oxide (GO) and reduced graphene oxide (rGO) have solidified their role as cornerstone nanomaterials in the pursuit of sustainable technology. This review synthesizes recent advances in harnessing the unique properties of GO and rGO such as their tunable surface chemistry and exceptional electrical conductivity for applications spanning environmental remediation and energy storage. In the environmental domain, they function as superior adsorbents and catalysts for the removal of hazardous pollutants. Concurrently, in the energy sector, their integration into supercapacitors and battery electrodes significantly enhances energy and power density. The adaptability of these materials also facilitates the creation of highly sensitive sensors and biosensors. However, the transition from laboratory research to widespread industrial application is hindered by challenges in scalable production, environmental health and safety concerns, and long-term stability. This review enhances the understanding of GO and rGO’s diverse applications and paves the way for future sustainable technologies in energy and environmental sectors. Full article

Chemical complexity is not a nuisance to be minimized in origin of life research, it is an enabling condition. This second edition of the Special Issue on the Origin of Life in Chemically Complex Messy Environments gathers contributions that embrace multicomponent mixtures, dynamic geochemical settings, and nonequilibrium processes. The papers collected here survey surface hydrothermal routes to reactive nitriles, groundwater evolution of alkaline lakes, and transition metal sulfide-driven amino acid and amide formation without cyanide. They report one pot nucleoside and nucleotide synthesis from formamide over cerium phosphate, review non aqueous organophosphorus pathways, and probe peptide rich mixtures and formose type networks under serpentinization associated minerals. The issue also advances conceptual frameworks, including atmospheric photochemical signatures for biosignature discrimination, the role of chiral mineral surfaces in enantioseparation, and computational simulations of the origin of LUCA. Together, these studies position messy chemistry as a crucible that turns chemical diversity and environmental heterogeneity into routes toward organization and function. Full article

This study builds on previous research into the surface modification of beech wood with polyethyleneimine (PEI) prior to finishing it with a waterborne coating. Poly(diallyldimethylammonium chloride) (PDADMAC) is introduced as an alternative cationic polyelectrolyte for the pretreatment of beech wood surfaces. Wood samples were treated with aqueous 1% PDADMAC solutions of low (LMW—8000 g mol⁻¹) and high (HMW—100,000–200,000 g mol⁻¹) molecular weights, with or without NaCl addition. The effects of the treatments on wood surface chemistry, wettability, surface energy, water absorption, coating penetration, coating adhesion strength, and surface roughness of coated wood were analysed using FTIR, fluorescence microscopy, SEM/EDS, and standardised tests commonly used in wood surface finishing. The results showed that polyelectrolyte pretreatment modified the surface properties of wood, reducing water absorption and surface roughness without significantly affecting coating adhesion strength. PDADMAC formed a more uniform surface layer of wood with limited coating penetration, and NaCl addition improved wood surface smoothness (reducing surface roughness parameters of coated wood by 23%–29%, in samples treated with PDADMAC LMW with 0.01 M NaCl). These findings confirm that cationic polyelectrolyte pretreatment enhances the compatibility and performance of waterborne coatings, offering an environmentally friendly approach to improving wood–waterborne coating interactions. Full article

The sea surface microlayer (SML) is a critical biogeochemical boundary, playing a key role in air–sea exchange processes, yet its sampling remains challenging due to potential dilution from subsurface water layers, susceptibility to contamination and labor- and time-consuming procedures. The design, development and operational verification of a research unmanned surface vehicle (USV), equipped with samplers for collecting both sea surface microlayer and subsurface water samples (SSW), are described in this study. The InterSeA autonomous vessel is of the catamaran type, equipped with an SML sampler consisting of rotating glass discs and a peristaltic pump for collecting SSW samples. Verification analysis with traditional manual sampling techniques (glass plate and mesh screen) revealed that the InterSeA achieved comparable results in terms of reproducibility and contamination control for both the inorganic and organic analytes examined. The results obtained highlight the effectiveness of autonomous platforms in achieving reliable, low-contamination SML sampling, emphasizing their suitability for broader use in marine biogeochemical research demanding high resolution and minimally disturbed interface measurements. InterSeA is one of the smallest and lightest USVs using rotating glass discs for SML sampling. Full article

The valorization of dredged sediments represents a major environmental and logistical challenge, particularly in the context of forthcoming regulations restricting their marine disposal. This study investigates the potential of untreated dredged sediments as sustainable raw materials for geopolymer binder development, with the dual objective of sustainable sediment management and reduction in cement-related environmental impact. Dredged sediments from the Grand Port Maritime de Bordeaux (GPMB) were activated with sodium hydroxide (NaOH) and sodium silicate (Na₂SiO₃), both alone and in combination, with supplementary aluminosilicate and calcium-rich co-products, to assess their reactivity and effect on binder performance. A multi-scale experimental approach combining mechanical testing, calorimetry, porosity analysis, Scanning Electron Microscopy and Energy-Dispersive Spectroscopy (SEM–EDS), X-ray diffraction (XRD), Thermogravimetric Analysis (TGA), and solid-state Nuclear Magnetic Resonance (NMR) was employed to challenge the commonly assumed inert behavior of sediments within geopolymer matrices, to elucidate gel formation mechanisms, and to optimize binder formulation. The results show that untreated sediments actively participate in alkali activation, reaching compressive strengths of up to 5.16 MPa at 90 days without thermal pre-treatment. Calcium-poor systems exhibited progressive long-term strength development associated with the formation of homogeneous aluminosilicate gels and refined microporosity, whereas calcium-rich systems showed higher early age strength but more limited long-term performance, linked to heterogeneous gel coexistence and increased total porosity. These findings provide direct evidence of the intrinsic reactivity of untreated dredged sediments and highlight the critical role of gel chemistry and calcium content in controlling long-term performance. The proposed approach offers a viable pathway for low-impact, on-site sediment valorization in civil engineering applications. Full article

This study addresses the need for sustainable and clean-label processing methods to enhance the functional and nutritional properties of sorghum flour. Reactive extrusion combining high shear forces and ozonization was selected as an environmentally friendly modification strategy. Whole and polished sorghum flours were processed using a twin-screw extruder, with ozone introduced via ozonated feed water under varying temperature profiles (140 °C and 160 °C) and moisture contents (20% and 23%). Characterization included specific mechanical energy (SME), textural attributes, water absorption and solubility indices (WAI/WSI), viscosity profiles (RVA), and surface chemistry via X-ray photoelectron spectroscopy (XPS). Finally, in vitro digestion was used to monitor the kinetics of starch and protein hydrolysis. Ozone reduced SME, increased extrudate density, and lowered expansion and fracture force, particularly in polished flour. The XPS confirmed successful oxidation, showing the conversion of hydroxyl groups into carbonyl and carboxyl groups. Ozone also improved water absorption but reduced solubility and decreased viscosity parameters in polished flour. In vitro digestion showed that extrusion ozonation enhanced protein digestibility at ~25%. At the gastric phase, ozonized whole samples showed 18.3% starch hydrolysis, and ozonized polished flour showed 8.3%, whereas non-ozonized flours exhibited ~25%. These findings prove that ozone-assisted reactive extrusion differentially changes sorghum flour properties, offering a promising approach for improved food applications. Full article

The construction sector faces the dual challenge of reducing energy consumption and mitigating the environmental burden of construction and demolition waste (CDW). Geopolymers offer a low-carbon alternative to Portland cement, yet their performance depends strongly on precursor composition. This study presents an extensive investigation of precursor chemistry, mechanical performance and phase composition, focusing on the partial substitution of ground granulated blast furnace slag (GGBFS) with mechanically activated CDW powder (15% and 30% by weight) alongside fly ash (FA). The oxide composition, amorphous content and particle size distribution were analyzed, using XRF, XRD and laser diffraction to evaluate the reactivity. Mortar samples were subsequently synthesized and tested for compressive and flexural strength, ultrasonic pulse velocity, density and porosity. The results demonstrate that while mechanically activated CDW incorporation decreases early strength compared with GGBFS-rich systems, compressive strengths above 45 MPa were attained at 28 days, with continuous improvement to >69 MPa for aged composites. The relationship between precursor chemistry, precursor sizes and mechanical performance highlights the feasibility of CDW valorization in geopolymer binders, contributing to energy efficiency, circular economy strategies and sustainable construction materials. Full article

Understanding the structure of zooplankton communities in water contaminated with per- and polyfluoroalkyl substances (PFAS) is essential to the conservation of aquatic biodiversity. This study focused on the Weihe River and systematically characterized the PFAS pollution. By employing environmental DNA metabarcoding, multivariate statistics, and Partial Least Squares Path Modeling (PLS-PM), we systematically analyzed the associations between PFAS and zooplankton within the context of water parameters. The results showed that short-chain PFAS were the dominant PFAS compounds in the Weihe River (accounting for 70.89% of ΣPFAS), and that both PFAS and the zooplankton community exhibited similar spatial patterns. PLS-PM identified a key pathway: water chemistry promoted PFAS accumulation, which in turn exerted taxon-specific effects. Short-chain PFAS were primarily associated with Cercozoa, and path analysis indicated negative relationships, whereas long-chain PFAS were correlated with Ciliophora and Rotifera. Specific taxon within Ciliophora showed potential as bioindicators. Additionally, higher community relative abundance was associated with reduced diversity loss under anthropogenic stress, indicating a potential buffering response. Overall, short-chain PFAS, in combination with water parameters, were associated with higher ecological risk to zooplankton communities. This study highlights the importance of including indirect pathways and taxon-specific responses into risk assessments of emerging contaminants. Full article

This review critically examines the implementation of Universal Design for Learning (UDL) in science education, providing an integrative overview of research, methodologies, and disciplinary applications. The first section explores UDL across educational stages—from early childhood to higher education—highlighting how age-specific adaptations, such as play-based and outdoor learning in early years or language- and problem-focused strategies in secondary education, enhance engagement and equity. The second section analyses science-specific pedagogies, including inquiry-based science education, the 5E model (Engage, Explore, Explain, Elaborate, Evaluate), STEM/STEAM approaches, and gamification, demonstrating how their alignment with UDL principles fosters motivation, creativity, and metacognitive development. The third section addresses the application of UDL across scientific disciplines—biology, physics, chemistry, geosciences, environmental education, and the Nature of Science—illustrating discipline-oriented adaptations and inclusive practices. Finally, a section on multiple scenarios of diversity synthesizes UDL responses to physical, sensory, and learning difficulties, neurodivergence, giftedness, and socio-emotional barriers. The review concludes by calling for enhanced teacher preparation and providing key ideas for professionals who want to implement UDL in science contexts. Full article

1,4-Dihydropyridines (1,4-DHPs) are privileged heterocycles with broad relevance in medicinal chemistry and redox-related applications. However, conventional Hantzsch syntheses typically require prolonged thermal heating and often suffer from limited efficiency and regioselectivity. Herein, we report a sustainable and efficient microwave-assisted protocol for the synthesis of 1,4-DHPs, employing phosphotungstic acid (HPW) as a heteropolyacid catalyst in PEG-400 as a green reaction medium. The multicomponent cyclocondensation proceeds rapidly under microwave irradiation, affording the desired 1,4-DHP derivatives in good to excellent yields within short reaction times. Compared with classical acid-catalyzed conditions, the HPW/PEG-400 system markedly enhances regioselectivity toward the 1,4-DHP framework while simultaneously reducing energy input. Moreover, the catalytic system exhibits good recyclability, underscoring its potential as a practical and environmentally responsible platform for the synthesis of bioactive 1,4-dihydropyridine scaffolds. Full article