Search Results (15,113)

Heavy oil and extra-heavy oil represent mobility-limited petroleum resources because supramolecular associations of asphaltenes and resins, together with strong interfacial resistance, generate extremely high apparent viscosity. In recent years, nanotechnology has emerged as a promising approach for viscosity management and enhanced oil recovery (EOR). This review critically examines recent advances in nano-assisted viscosity reduction from a reservoir-operational perspective and organizes the literature into two field-relevant categories: metal-based and non-metal nano-systems. Metal-based nanoparticles (NPs) mainly promote catalytic aquathermolysis and related bond-cleavage and hydrogen-transfer reactions under hydrothermal conditions, enabling partial upgrading and persistent viscosity reduction during thermal recovery. In contrast, non-metal nano-systems—particularly silica- and graphene-oxide-derived materials—primarily operate through interfacial and structural regulation mechanisms at low or moderate temperatures. These effects include wettability alteration, interfacial-film stabilization, modification of asphaltene aggregation behavior, and the formation of dispersed-flow regimes such as Pickering-type emulsions that reduce apparent flow resistance in multiphase systems. Beyond summarizing nanomaterial types, this review emphasizes reservoir-scale considerations governing field applicability, including brine stability, NPs transport and retention in porous media, and formulation compatibility. Comparative analysis highlights the distinct operational windows of thermal catalytic nano-systems and cold-production nano-systems, providing a reservoir-oriented framework for designing nano-assisted viscosity-reduction technologies. Full article

The large-scale generation of industrial waste salts (IWSs) across sectors such as coal chemical, pesticide, pharmaceutical, and dye manufacturing has raised increasing environmental and regulatory concerns. These IWSs often exhibit complex physicochemical profiles—featuring high concentrations of inorganic salts, persistent organic pollutants, and trace heavy metals—that pose significant challenges for both safe disposal and resource recovery. This review provides a comprehensive and pollutant-oriented overview of industrial waste salts, focusing on their sector-specific characteristics, dominant contaminant types, and tailored treatment strategies. Removal pathways for organic matter (e.g., thermal decomposition, advanced oxidation) and inorganic impurities (e.g., precipitation, ion exchange) are systematically analyzed, followed by technical pathways for salt separation based on crystallization and membrane processes. Resource utilization routes for major salt components, particularly NaCl and Na₂SO₄, are critically assessed in terms of technical feasibility, impurity tolerance, and end-use compatibility. The emergence of reclaimed salt quality standards and sector-specific impurity thresholds reflects a paradigm shift from purity-based to performance-based reuse evaluation. Finally, the review highlights future priorities including adaptive impurity control, downstream-specific salt grading, and enforceable regulatory frameworks to ensure the safe, scalable, and circular deployment of reclaimed salts in industrial systems. This study supports the coordinated advancement of control technologies and reuse standards, enabling the transformation of waste salts from environmental liabilities to secondary resources. Full article

As a result of the high safety, low cost, and environmental benignity, aqueous zinc-ion batteries are regarded as one of the most promising candidates for next-generation large-scale energy storage systems. However, their further development is constrained by performance bottlenecks in existing cathode materials, including capacity, cycle life, and reaction kinetics. In this study, a high-entropy design strategy is employed to synthesize the metal oxide (FeNiMnMgCuCo)₃O₄ with a cubic spinel structure, and its electrochemical performance as a cathode for zinc-ion batteries is systematically evaluated. The prepared (FeNiMnMgCuCo)₃O₄ high-entropy cathode exhibits high reversible capacity (341.3 mA h g⁻¹ at 0.1 A g⁻¹) and remarkable long-term cycling stability (76.1% retention after 1000 cycles at 3 A g⁻¹). This work not only demonstrates a high-entropy cathode material with practical potential but also provides new research insights for optimizing zinc-ion storage performance through composition design and entropy regulation. Full article

In this study, commercial Ospray-2507 super-duplex stainless steel powder was investigated for the first time as a potential metal support material for solid oxide cells. Initially, metal supports were fabricated and processed in air using various sintering profiles, followed by comprehensive mechanical, structural and electrochemical characterization. The optimal sintering condition was identified as 900 °C for 5 h. Subsequently, sintering under a H₂ atmosphere was explored, and its effects on the microstructural and functional properties of the metal supports were systematically to assessed to evaluate the influence of the sintering atmosphere on material performance. Although X-ray diffraction patterns showed no phase changes between the two sintering atmospheres, notable improvements were observed in mechanical, electrochemical, and microstructural properties under H₂ sintering. XPS spectra reveal that both air- and hydrogen-treated surfaces remain rich in chromium (Cr) and Manganese (Mn), which together dominate the surface and consequently attenuate the signal from the underlying iron. The thickness of the Cr- and Mn-based oxide layer decreases when sintering MS in H₂ atmosphere. Specifically, mechanical strength, as measured by three-point bending tests, increased by a factor of 12.5, and hardness rose from 500.3 to 523.5 HV. Furthermore, electrical conductivity also improved significantly, exhibiting an approximately 2.3–2.4 fold increase under H₂-sintered conditions. Full article

Pure LaFeO₃@C and LaCoO₃@C and substituted LaFe_1-xCo_xO₃ and LaCo_1-xFe_xO₃ perovskites (x = 0.10; 0.30) were used as catalysts for the liquid-phase oxidation of furfural at 150 °C and 30 bar of O₂ pressure. The perovskites were characterized by XRD, H₂-TPR, N₂ physisorption, TPR-MeOH, and XPS. The carbon in situ incorporation (@C) increases the surface area, favoring oxygen mobility leading to LaFeO₃@C stabilizing the redox pair Fe³⁺/Fe²⁺. In contrast, no evidence of the formation of a LaCoO₃@C perovskite structure through @C incorporation was observed. The gradual substitution of Fe with Co (10 and 30%) in LaFeO₃@C decreases the crystallinity, redox and basic properties, and surface area. For LaCoO₃@C, after the substitution of Co with 10 and 30% of Fe, only metal (La, Fe, Co) oxides as segregated phases were observed. The highest catalytic activity and selectivity to maleic acid of LaFeO₃@C is attributed to the higher surface area, crystalline structure, and surface-reducible Fe³⁺ species, favoring oxygen mobility and promoting their more oxidizing capacity. The lower catalytic activity of LaCoO₃@C, the Co- and Fe-substituted LaFeO₃@C and LaCoO₃@C catalysts, is attributed to the smaller surface area, and the similar selectivity towards maleic acid, 5-hydroxy-2(5H) and furanone indicates that the active site type is not modified in comparison to LaFeO₃@C. Full article

In this work, we report the fabrication of SnO₂-based composite nanostructures in view of their application as a sensor element toward N₂O gas exposure. The samples were produced by laser ablation of a composite SnO₂-TiO₂ target performed in air at atmospheric pressure (in open air). We examined how the structure, morphology, composition, and physical properties of the samples change with the TiO₂ content being introduced into the SnO₂ target. The laser ablation of SnO₂-based targets in open air produced samples with a structure in which SnO₂ and SnO crystal phases co-existed, as the crystal phases were distinguished in separate nanoparticles. The nanoparticles formed a complex porous structure with oxygen-related defects. We investigated the gas-sensing properties of composite SnO₂-based sensor elements working under UV irradiation. The highest response to N₂O exposure and the fastest response/recovery times were demonstrated by the sensor element produced by the laser ablation of a composite target prepared by 10 wt% TiO₂ in SnO₂. Additionally, we found that a small amount (below 0.1 wt%) of noble metal (Pt) added to the sensor element substantially improved the gas sensor performance without inducing significant structural and/or morphological changes. Further, we explored how simultaneous irradiation of the sensor surface with UV and visible light changes the sensor properties. The best sensor performance toward N₂O exposure was achieved by irradiating the Pt-doped SnO₂-TiO₂ sensor surface simultaneously with UV and red lights. Full article

Oxidative catalytic fractionation (OCF) under the lignin-first strategy has emerged as a critical technological approach for biomass refining. To address the inevitable carbohydrate degradation and lignin condensation in conventional OCF, this study designed a cobalt-doped layered double hydroxide oxide (Co-LDO) catalyst compatible with non-alkaline (without Brønsted bases) organic systems, which exhibits excellent performance in poplar biomass OCF. With a straightforward preparation process, the Co-LDO catalyst yields high-content oxidized lignin oligomers while efficiently retaining carbohydrates, providing feedstock rich in carbohydrates (cellulose and hemicellulose) for the subsequent production of bioenergy and biomass-based chemicals. Under optimized conditions screened via systematic reaction condition investigation and metal-doped LDO catalyst evaluation, the process achieved a 94.01 wt% delignification rate, with 72.19 wt% of lignin converted into lignin oligomer oil, supported by detailed product composition and structural characterization. Meanwhile, 74.14 wt% hemicellulose and 98.23 wt% cellulose were recovered in solid residues, with structurally intact hemicellulose retention being 2.3 times higher than in traditional OCF. Mass balance calculation confirmed a total poplar refining yield of 81.58 wt%. In summary, this Co-LDO-catalyzed OCF strategy provides a high-activity non-precious metal system, effectively suppressing lignin condensation while preserving high-yield carbohydrates, realizing the efficient full-component refining of poplar biomass. Full article

The spontaneous reduction of one Cu(II) center to Cu(I) in a series of three dinuclear copper complexes in acetonitrile is described. These complexes feature ligands that include nitrogen donors from a diazecine ring and imidazole, designated as promeim, thiopromeim, and thioenmeim; the latter two incorporate a thioether as a third donor component. The mechanism of metal reduction was elucidated through spectroscopic and spectrometric techniques (UV-vis, EPR, XANES, ESI-MS) and electrochemical tools, in combination with DFT electronic structure calculations. Based on these and on spectroelectrochemical results, a mechanism is proposed in which the one-electron reduction of one of the copper ions is achieved by a one-electron oxidation in the adjacent imidazole group, while the other copper ion remains as Cu(II). The persistent detection of superoxide and peroxide over long periods suggests a mechanism in which a catalytic cycle involving electron transfer occurs between copper, ligand, and dioxygen. Full article

The redox mechanisms of silica-supported Ni particles were investigated using their in situ X-ray absorption fine structure, providing mechanistic insights into partially reduced NiO and partially oxidized metallic Ni. The results of surface oxidation of partially reduced NiO particles at room temperature revealed that the surface was not fully covered with metallic Ni and that metallic Ni had also formed within the particle interior. During NiO particle reduction, the process initiates at specific surface sites, and before the metallic Ni phase fully covers the surface, O²⁻ ions are expelled from the particle. Conversely, the oxidation of metallic Ni particles progresses inward from the surface, with an accompanying increase in the thickness of the NiO layer that forms upon O₂ exposure at room temperature. This mechanism is supported by observations that the reduction of a thin NiO shell on metallic Ni particles was completed below 200 °C, while reduction temperatures shifted to higher values as the NiO layer thickness increased. The distinct oxidation and reduction mechanisms are attributed to differences in the migration direction of O²⁻ ions. During reduction, it is proposed that O²⁻ ions within the particles migrate to the surface along the interface between the NiO phase and the metallic Ni phase. This study elucidates the detailed mechanism behind the redox interconversion between NiO and metallic Ni in solid catalyst particles. Full article

The increasing adoption of biopolymeric and nanostructured coatings for horticultural produce has emerged as a sustainable strategy to mitigate postharvest losses and extend shelf life. However, while their technological performance has been extensively documented, comprehensive and integrative assessments of biosafety, potential human health implications, and environmental risks profiles are still insufficiently explored. This review critically analyzes recent advances in polysaccharide, protein, and lipid-based coatings, including nanoenabled systems incorporating metallic nanoparticles and bioactive agents. The mechanisms underlying gas barrier properties, antimicrobial activity, and preservation efficacy are discussed alongside degradation pathways in composting, soil, and aquatic environments. Particular attention is given to nanoparticle release, migration potential, gastrointestinal fate, and toxicological endpoints such as oxidative stress, genotoxicity, endocrine disruption, and immunomodulation. Ecotoxicological evidence across trophic levels, from microorganisms and invertebrates to fish and amphibians, is examined, highlighting sublethal and mechanistic biomarkers relevant to environmental risk assessment. Regulatory frameworks from major agencies are also compared to contextualize current safety standards and limitations. Overall, although biopolymeric coatings represent promising alternatives to conventional plastics, their life-cycle impacts, transformation products, and nano-related uncertainties require comprehensive, multilevel risk evaluation to ensure truly sustainable and safe postharvest applications. Full article

Background: Miscarriage is the most common complication of pregnancy. Current trends in medicine point to the increasing importance of evidence-based personalization in diagnostic and therapeutic processes. Purpose: The aim of this study was to develop an innovative prenatal screening panel and treatment strategy for miscarriage prevention. Results: Previous studies have demonstrated an imbalance between oxidative and anti-oxidant mechanisms, resulting in systemic oxidative stress in women with a history of miscarriage. The importance of monitoring toxic metal concentrations as potential risk factors in early pregnancy was confirmed. The involvement of NETs in the pathogenesis of miscarriages was demonstrated, while identifying early biomarkers of this process. The effect of BPA on the activation of NETs and the development of an inflammatory response in the female participants was demonstrated. Furthermore, a mechanism of NO-dependent oxidative–anti-oxidative imbalance and NLRP3 inflammasome activation during pregnancy loss was identified in a pathway independent of NET formation, excluding apoptosis. The participation of certain microRNA molecules in reproductive failure and their value in minimally invasive diagnostics in the early stages of pregnancy have been proven. Conclusions: The proposed screening panel accounts for the above parameters, represents a novel approach in modern prenatal care, and prioritizes miscarriage prevention strategies. Full article

High-iron red mud presents a major obstacle to comprehensive resource utilization, as iron and aluminum minerals form tightly interwoven and encapsulated structures that resist conventional separation, hindering efficient co-recovery of these valuable elements. This study aimed to address this bottleneck by developing an effective strategy for iron–aluminum separation and synergistic recovery. A reduction smelting process was conducted in a sealed electric furnace using internally carbon-containing red mud pellets, enabling phase reconstruction to regulate aluminum-bearing phases while achieving iron–aluminum separation. XRD and SEM analysis verified that iron oxides were reduced to metallic iron with recovery exceeding 98%, and aluminum-bearing phases were selectively converted into active α-Al₂O₃ and mainly dodecacalcium hepta-aluminate (Ca₁₂Al₁₄O₃₃) in the slag. Under optimized Bayer leaching conditions (150 g/L NaOH, 240 °C, 90 min, liquid-to-solid ratio 6:1), aluminum extraction exceeded 60%, comparable to conventional red mud processing. This work overcomes the technical barrier of iron–aluminum co-recovery from high-iron red mud, offering a practical and efficient route for its sustainable valorization. Full article

The high-temperature corrosion behavior of A1, T22, and T91 steels was investigated in molten nitrate salts at 400, 500, and 600 °C during 100 h of exposure. The combined influence of temperature and chromium content on corrosion kinetics and oxide-scale stability was evaluated using open-circuit potential (OCP), linear polarization resistance (Rp), electrochemical impedance spectroscopy (EIS), scanning electron microscopy, X-ray diffraction, and cross-sectional elemental mapping. OCP measurements showed a progressive shift toward more negative potential with increasing temperature, indicating enhanced oxidation tendency. Electrochemical measurements revealed a systematic decrease in Rp and impedance magnitude as temperature increased, confirming accelerated corrosion kinetics and reduced interfacial resistance. EIS spectra exhibited two characteristic time constants associated with the outer corrosion products and the inner metal/oxide interface. Significant differences in scale growth were observed depending on alloy composition. At 600 °C, oxide thickness reached approximately 700–800 μm for A1, ~100 μm for T22, and ~10 μm for T91. Chromium-containing steels promoted the formation of a compact Cr-rich inner oxide layer that improved scale adhesion and suppressed the exfoliation phenomena observed in A1 steel. Overall, temperature controls corrosion kinetics, whereas chromium content governs oxide-scale compactness and long-term stability in molten nitrate environments. Full article

Extra-virgin olive oil (EVOO) is a chemically complex lipid matrix whose minor constituents—especially phenolic secoiridoids—drive sensory quality, oxidative stability, and health benefits. However, these bioactives are vulnerable to heat, light, oxygen, and pro-oxidant metals during processing and distribution, while the high cost of EVOO often makes it a target for adulteration and mislabeling. This review critically assesses nano-enabled, food-grade strategies that (i) preserve phenolics and aroma compounds through nanoencapsulation, inclusion complexes, Pickering stabilization, and structured lipid systems; (ii) control their release and bioaccessibility during digestion; and (iii) enhance authenticity verification via sensor-ready packaging, spectroscopy/chemometrics, and digital traceability systems (IoT, machine learning, blockchain). We align these innovations with the “product identity constraints” of the EVOO category and with official quality standards used in routine control (IOC/EU). Finally, we explore circular valorization of olive-mill by-products within food-centered biorefineries, outlining pathways to convert biomass into ingredients, materials, and energy, thus reducing environmental impacts. Research priorities are proposed to develop scalable, regulation-compliant nanotechnologies that extend shelf life and increase consumer trust without compromising EVOO category standards. Full article

The use of nanoparticles (NPs) synthesized from plant extracts is an alternative to conventional pesticides for the control of agricultural pests. This study aimed to optimize the conditions of synthesis of silver–zinc nanoparticles (Ag-ZnNPs) using extracts of Ocimum basilicum L. and Crotalaria longirostrata Hook. & Arn. and to evaluate their phytotoxic impact on maize seedlings. The Ag-ZnNPs (Ag-Zn nanoparticles) were synthesized by redox reaction between metal ions and reducing metabolites present in the extracts. A response surface methodology (RSM) with three factors (extract concentration, heating time and pressure) was applied to determine the optimal synthesis conditions. The phytotoxicity of nanoparticles (NPs) on maize seedlings was subsequently evaluated on root growth, oxidative stress enzymes (CAT, POD, and APX), and physiology of seedlings. Nanoparticles synthesized from C. longirostrata extract demonstrated superior properties, with an optimization of synthesis (R² = 95.3%) where the extract concentration (1:4 v/v; p < 0.01) was the critical factor influencing the reduction of metallic ions to nanoparticles. These NPs exhibited superior stability, smaller size (<100 nm), and zeta potential greater than 30 mV compared with O. basilicum extracts. Their NPs exhibited poorer optimization of synthesis (R² = 43.8%) without the effect of any of the variables evaluated. Essentially, C. longirostrata NPs showed no phytotoxic effects on maize seedlings’ physiological parameters and enhanced root growth (117.2 mm) without negatively affecting photosynthesis (PSII 70-81 FvFm). Ag-ZnNPs synthesized with C. longirostrata exhibited optimal stability and size, along with no observed possible phytotoxicity effects, unlike O. basilicum NPs, which cause stress on maize seedlings. Therefore, Crotalaria longirostrata NPs could represent a promising material for agricultural pest control, with no apparent adverse effect on maize crops. Full article