Search Results (2,777)

Choline salts represent sustainable and safe electrolyte systems. In this study, an aqueous 1 M choline nitrate solution was employed to prepare hydrogel polymer electrolytes (HPE) via in situ photopolymerization. To enhance compatibility between the electrolyte and polymer matrix, choline methacrylate was synthesized and used as a functional monomer alongside HEMA and PEGDA. The photocurable formulation contained 70 wt.% electrolyte and 30 wt.% monomer mixture. Subsequent electrolyte uptake increased the electrolyte fraction in the HPE to 87 wt.%. The use of choline methacrylate enabled the formation of transparent HPE with favorable mechanical performance, showing puncture resistance of 0.33 N and 0.28 N at elongations of 7.9 mm and 4.4 mm for samples with 70 and 87 wt.% electrolyte, respectively. High ionic conductivity was achieved, reaching ~18 mS/cm and ~34 mS/cm for HPE with 70 and 87 wt.% electrolyte. Finally, a capacitor assembled with HPE containing 87 wt.% electrolyte demonstrated good operational parameters, confirming the applicability of this system in energy storage devices. This work highlights the potential of choline-based electrolytes and polymerizable choline derivatives as functional components for the design of efficient, safe, and environmentally friendly gel polymer electrolytes. Full article

Incorporating Cu into gold-based catalysts effectively reduced nanoparticle sintering and free carbonate accumulation, promoting long-term preservation of catalytic surface area over time. This study explores the catalytic activity of monometallic Au and bimetallic AuCu catalysts with varying Au:Cu atomic ratios (1:0.5, 1:1, and 1:1.5) that were synthesized on $\gamma$-Al${}_2$O${}_3$ via sequential deposition–precipitation with urea. The catalysts were pretreated in either air or H${}_2$ and evaluated for CO oxidation activity and stability. A comprehensive characterization (EDS, BET, TEM, H${}_2$-TPR, O${}_2$-TPO, XPS, DRIFTS, and UV–Vis) was used to investigate particle size, metal oxidation states, and redox properties. Among all materials, the AuCu 1:1 catalyst exhibited the highest low-temperature CO conversion (>90% at 0 ${}^{\circ }$C) and improved stability during 24 h tests, reflecting minimal nanoparticle sintering as confirmed by TEM analysis. In situ DRIFTS revealed that the presence of Cu${}^{+}$ and Cu${}^{2+}$ minimizes the accumulation of free carbonates (one of the main deactivation pathways in Au/$\gamma$-Al${}_2$O${}_3$) while promoting the formation of reactive intermediates that facilitate CO${}_2$ production. Notably, air pretreatment at moderate temperature proved as effective as H${}_2$ pretreatment in activating both monometallic and bimetallic catalysts. These findings highlight the role of Cu as a structural and electronic promoter of gold, offering practical guidelines for designing durable, cost-effective catalysts for low-temperature CO oxidation on non-reducible supports. Full article

This study provides the first comprehensive characterization and classification of organic microfacies within the globally significant Jurassic hydrocarbon source rocks of Iraqi Kurdistan. This study aims to resolve the knowledge gap in the Jurassic source rocks of northern Iraq by establishing the first organic microfacies classification scheme, utilizing an integrated petrographic and geochemical approach to reconstruct the regional paleoenvironmental evolution and confirm the source rock’s petroleum potential. The Middle–Late Jurassic Sargelu, Naokelekan, and Barsarin formations were investigated using samples from the Mangesh-1 and Sheikhan-8 wells. Using cluster analysis, we identified five distinct organic microfacies (A–E). Microfacies A (highly laminated bituminite), B (laminated/groundmass bituminite), C (laminated rock/lamalginite), and D (massive organic-matter-rich) show the highest hydrocarbon generation potential. The findings reveal a clear paleoenvironmental evolution: the Sargelu Formation was deposited in anoxic open marine conditions (microfacies C, D); the Naokelekan Formation represents a progressively restricted silled basin with intense anoxia leading to condensed sections dominated by microfacies A, which shows the highest source rock potential; and the Barsarin Formation reflects increasing restriction and hypersalinity, showing diverse microfacies (B, C, D, E) that captured variations in marine productivity and terrigenous influx. Principal component analysis (PCA) quantitatively modeled these paleoenvironmental gradients, aligning the distinct organic microfacies and their transitions with conceptual basin models. Geochemical analysis confirms that the organic matter is rich, predominantly Type II kerogen, and thermally mature, falling within the oil window. The presence of solid bitumen, both in situ and as evidence of migration (microfacies E), confirms effective hydrocarbon generation and movement. This integrated approach confirms the significant hydrocarbon potential of these Jurassic successions and highlights the critical role of specific organic microfacies in the region’s petroleum system, providing crucial guidance for future hydrocarbon exploration in northern Iraq. Full article

In light of frequently occurring wellbore instability such as wellbore collapse and sand production that often occur in drilling and the completion of shale oil and gas development, we propose one-run shape memory thermosensitive screen technology that can expand spontaneously at a specific temperature to help strengthen the formation. Based on the theory of thermal expansion and large deformation of shape memory materials, the expansion process of the thermosensitive screen is calculated by the finite element method. After expanding to the wellbore wall, the effects of the screen squeezing force on the formation production parameters are evaluated theoretically. The analysis shows that the radial compressive stress of the thermosensitive screen decreases with the increase in the radial distance, but as the original outer diameter of the thermosensitive screen is greater than the wellbore diameter, it can provide extrusion force for the wellbore wall. According to the in situ stress model, the extrusion force after the screen contacts the wellbore can effectively improve the stress distribution near the wellbore and reduce the impact of sand production caused by formation instability. Moreover, in shale oil and gas completion, it can effectively increase the bottom hole flowing pressure and drawdown pressure. Full article

Surgical site infections in oral and maxillofacial interventions are often exacerbated by biofilm formation, and current antimicrobial treatments are hampered by issues such as resistance and adverse effects. This article aimed to develop, characterize, and evaluate the antimicrobial activity of Lippia sidoides Cham. essential oil (LSEO) gel composed of poloxamer (P) and chitosan (C). Gas chromatography–mass spectrometry (GC-MS) analysis identified thymol as the major component of LSEO (71.04%). In situ P-gels containing LSEO (0.25–1.0%) were produced with and without C. The addition of C resulted in gels with nanometric particle sizes (263.8 ± 231 nm; PDI 0.39 ± 0.17) and a positive zeta potential (+4.81 ± 1.97 a + 8.19 ± 0.51 mV), exhibiting pseudoplastic behavior in rheological analysis. The sol–gel transition temperature (Tsol–gel) was found to be between 20 and 28 °C, with a transition time at 37 °C ranging from 18.76 ± 1.24 s to 46.46 ± 8.89 s. LSEO showed MIC values of 256, 128, and 128 µg/mL against Staphylococcus aureus, Escherichia coli, and Candida albicans, respectively, while in situ LSEO gels presented MIC values above 5 µg/mL for all tested strains. Therefore, the developed gel containing LSEO showed promising application in dentistry, offering a potential new treatment perspective for surgical site infections in oral and maxillofacial surgery. Full article

High-entropy materials have emerged as promising candidates for high-temperature structural, magnetic, and electrochemical applications due to their unique combination of compositional complexity, thermal stability, and tailored functionality. In this study, self-propagating high-temperature synthesis (SHS) was employed to fabricate high-entropy composite in a Ti–Cr–Mn–Co–Ni–Al–C multicomponent system with a focus on elucidating the effect of titanium content on the combustion parameters, as well as on the phase and structure formation patterns of the resulting materials. In situ profiling enables evaluating the maximum combustion temperature of 1560 °C, combustion wave propagation velocity ranging from 0.22 to 4.3 mm/s depending on titanium content, and heating and cooling rates of 300–2000 °C/s and 3 °C/s during synthesis. The synthesized powders exhibited a bimodal particle size distribution, with ~90% of particles below 25 μm and a D50 of 5.38 μm. Post-synthesis densification via spark plasma sintering (SPS) at 1250 °C under 45 MPa yielded dense bulk samples, which exhibited a high relative density and high Vickers microhardness of 1270 ± 35 HV10 attributed to fine TiC dispersion and secondary carbide formation. Thermogravimetric analysis performed under air flow with a heating rate of 20 °C/min showed enhanced thermal stability for both the powder and the sintered bulk. These findings demonstrate the efficacy of SHS for rapid, energy-efficient fabrication of high-entropy composites and underscore the critical role of composition in tailoring their structural and mechanical properties. Full article

The effect of KOH concentration as a boron-free coolant for prospective use in Small Modular Reactors (SMRs) on the corrosion of Alloy 690 is studied by in situ impedance spectroscopy at 280 °C/9 MPa during 168 h exposure in a flow-through cell connected to a high-temperature/high-pressure loop. To follow further oxidation of the passive film, the samples were subsequently polarized up to potentials 0.5 V more positive than the corrosion potential. The formed oxides were analyzed ex situ by measuring the atomic concentration of the constituent elements via glow discharge optical emission spectroscopy (GDOES) depth profiling. The Mixed-Conduction Model for Oxide Films (MCM) was employed to quantitatively interpret the impedance results. The estimated parameters are used to quantify the influence of KOH concentration and anodic polarization on oxide formation and soluble product release rates. Results are compared to those obtained in the nominal primary chemistry of pressurized water reactors and indicate that Alloy 690 can also be successfully used as a steam generator tube material in SMRs. Full article

Surface coatings have proven highly effective in addressing the critical challenges of friction, wear, and corrosion on steel substrates, which are responsible for over 80% of mechanical failures in industrial applications. Recent research highlights that advanced coatings—such as ceramic carbides/nitrides, high-entropy alloys, and metal-matrix composites—significantly enhance hardness, wear resistance, and environmental durability through mechanisms including protective oxide film formation, solid lubrication, and microstructural refinement. Moreover, these coatings exhibit robust performance under combined tribological-corrosive (tribocorrosion) conditions, where synergistic interactions often accelerate material degradation. Key developments include multilayer and composite architectures that balance hardness with toughness, self-lubricating coatings capable of in situ lubricant release, and active or self-healing systems for sustained corrosion inhibition. Despite these advances, challenges remain in predicting coating lifetime under multifield service conditions and optimizing interfacial adhesion to prevent delamination. Future efforts should prioritize multifunctional coating designs, improved tribocorrosion models, and the integration of sustainable materials and AI-driven process optimization. This review consolidates these insights to support the development of next-generation coatings for extending the service life of steel components across demanding sectors such as marine, aerospace, and energy systems. Full article

A composite material based on polyvinyl alcohol (PVA) and hydroxyapatite modified with magnesium (0.3; 0.5; 1.0 mol) was developed using the in situ mineralization method. A thorough analysis confirmed the formation of a two-phase system, with a uniform distribution of HA particles within the PVA matrix. In addition, the analysis confirmed the successful incorporation of magnesium into the crystal lattice without the formation of secondary phases. The material exhibited a developed macroporous structure, with porosities ranging from 50 to 200 μm. In order to ensure that the rheological properties of the composition were suitable for 3D printing, 4 wt.% gelatin was added, resulting in stable scaffolds. In vitro studies demonstrated high biocompatibility of the materials and a synergistic effect of the components: PVA has been demonstrated to neutralise the cytotoxic effects of HA, while magnesium has been shown to statistically significantly increase the viability of macrophages. The combination of a polymer matrix with an inorganic phase results in a material that exhibits both elasticity and bioactivity. The structural and functional characteristics of these systems render them promising materials for tissue engineering, particularly for bone regeneration and the creation of biocompatible 3D scaffolds. Full article

The combination of microplasma generation and optical multi-material fiber technologies enables real-time diagnostics. The stack-and-draw technique has emerged as a promising method for creating multimaterial fibers suitable for plasma-based diagnostics. The elaboration of such devices for the generation of long-lasting microplasma for real-time and remote analyses remains challenging due to the difficulties of reaching long lengths without defects and with continuous electrodes. Post-functionalization of the electrode surface is also required to increase the plasma emission duration. In this study, glass was preferred over polymers for producing rectangular fibers (ribbons) that are easy to stack without wasting space and are resistant to high operating temperatures. Conversely, an aluminum alloy was chosen for the electrodes to reduce discontinuity defects. With the chosen bi-electrode geometry, the cooling rate during drawing has to remain between 200 and 300 °C/s to limit defect formation and guarantee low electrical resistivity. During plasma generation, an in situ oxide layer forms on the tip of each electrode. This results in a significant increase in plasma emission duration without the need for an additional post-functionalization step after drawing. These ribbons were tested in combination with an optical emission spectrometer to create a miniature gas detector for hydrocarbons. Full article

The spontaneous formation and stability of a protective passive film on a metal surface are crucial for the metal material’s corrosion resistance during its service life. Passive films have been extensively studied, and our understanding of passive films has been significantly improved with the development of advanced analytical techniques. Modern synchrotron X-ray sources offer unprecedented possibilities for detailed analyses of passive films and for in situ and operando studies of passive films in both gaseous/aqueous environments, as well as in electrochemical environments. This mini review presents a short summary of recent studies on passive films, mainly focusing on stainless steels and nickel-base alloys, which utilize state-of-the-art synchrotron X-ray techniques, particularly X-ray photoelectron spectroscopy (XPS), often in combination with other synchrotron techniques such as X-ray adsorption, diffraction, reflectivity, and fluorescence. These reports demonstrate that synchrotron-based techniques greatly improve probing sensitivity and spatial resolution, enabling in situ and operando studies of passive films at solid–liquid interfaces. These studies reveal changes in the passive film and underlying alloy layer, highlighting the important role of hydroxides, as well as the inhomogeneity in passive films associated with the complex microstructures in advanced industrial alloys. Full article

Monitoring water quality in Welsh rivers has become a critical public concern, particularly in efforts to address pollution and protect the environment. This study presents the development and assessment of an interactive web and mobile application, featuring a real-time mapping interface built using the Mapbox framework. The platform provides stakeholders, including farmers, environmental agencies, and the public, with easy access to real-time water quality data using the Ystwyth River in Mid-Wales as a trial system. Users can click on map markers to view sensor readings for key water quality parameters. These include pH, electrical conductivity (EC), temperature, dissolved oxygen (DO), total dissolved solids (TDS) and nutrients levels such as nitrate (NO₃). This paper focuses on the feasibility of combining in situ sensor technology with a user-friendly mobile app to enable stakeholders to visualize the impact of land management practices and make informed decisions. The system aims to enhance environmental surveillance, increase transparency, and promote sustainable agricultural practices by providing critical water quality information in an accessible format. Future developments will explore the integration of artificial intelligence (AI) for predictive modelling and satellite data for broader spatial coverage, with the goal of scaling up the system to other catchments and improving proactive water quality management. Full article

The poly-lactic acid (PLA) coating was widely applied to the WE43 alloy to modulate its degradation for biomedical implants, a strategy whose long-term efficacy is critically dictated by the coating’s protective and ion-permeation properties under dynamic physiological flow. This work systematically investigates the corrosion performance under the such flow condition using a novel in situ monitoring method. This method enables a direct, in situ assessment of both the ion-permeation rate across the PLA membrane acted as the coating and the concurrent evolution of the electrochemical properties of the membrane as well as the WE43 alloy substrate. Results revealed that the applied flow accelerated the formation of micro-cracks in the PLA membrane, which facilitated the permeation of Na⁺ and Cl⁻ ions and thereby intensified the corrosion of the underlying substrate. During the initial 15 days, the ion permeation rates for Na⁺ and Cl⁻ ions under the flow condition were 0.097 and 0.042 mmol/(L·h), respectively. The degradation rate of the substrate exhibited a strong positive correlation with the concentration of permeated Cl⁻ ions. In contrast, the deposition of calcium-containing compounds was identified as a time-dependent process, governed by the permeation kinetics of Ca²⁺ ions through the membrane. Full article

Heterogeneous ice nucleation is a key process for ice cloud formation, snowfall, and freezing of water bodies. Ice nucleating particle (INP) cloud feedbacks are one of the largest sources of uncertainties in Earth’s Energy Budget. Although INPs are essential in the development of mixed-phased and glaciated clouds, their composition, sources, and cloud feedbacks remain poorly constrained. Previous studies have shown mixed results on the potential of light-absorbing particles (LAP), such as black carbon (BC) and high latitude dust (HLD), serving as INPs. However, many of these studies use laboratory or model-generated particles that may not represent the complex morphology and behaviors of ambient light-absorbing particles sufficiently. Here, we use in situ surface snow samples, collected during Spring 2018 in Svínafellsjökull, Iceland. The samples were analyzed by an immersion freezing mechanism for their ice nucleation activity (INA). Portions of the filtered samples were concentrated by lyophilization to observe the potential enhancement of INA. We investigated environmental samples of deposited aerosols to better understand the role activity of HLD and BC in ice nucleating activity in mixed-phase clouds in Iceland. We found concentrations of 16 ± 27 ng g⁻¹ and 33 ± 66 × 10⁶ ng g⁻¹ for BC and HLD, respectively. However, we found that isolated methanol-soluble organic aerosols have a more prominent role than BC and HLD in Iceland. We conclude that BC and HLD are insignificant INP but that they can inhibit INA from other INP. Full article

CO₂ fracturing (CO₂-Frac) is a novel technology for coal mine gas control, which is distinct from CO₂ Enhanced Coalbed Methane, and has been applied to alleviate in situ stress concentration and to eliminate coal and gas outbursts in coal mines. However, the reasons for the greatly varying effects of CO₂-Frac application among different regions remains largely unknown, and the influence of geological structures, particularly pre-existing fracture orientations, remains poorly understood. The equipment system of phase fracturing and permeability improvement of low-permeability coalbed methane and the gas phase fracturing and permeability improvement technology are studied and analyzed, and the engineering application is carried out in the head face of Xinyuan Coal Mine. This study conducted three CO₂-Frac experiments in the Xinyuan coal mine in which borehole orientations were varied, with the primary fracture strike of coal seam #3 in the Shanxi Formation ranging from N3°E to N15°E. The characteristics of reservoir stress redistribution after CO₂-Frac and its mechanism controlled by the orientation of primary fractures were explored based on the analysis of microseismic focal mechanisms. The results showed that (1) Both the fracturing section and the buffer section determined the stress relief effect of CO₂-Frac. While the different experiments showed largely similar stress relief effects of the fracturing section, the effects of the buffer section greatly differed. (2) The microseismic events generated by the CO₂-Frac in the borehole with an N–S orientation showed a more concentrated spatial distribution, with higher proportions of tensile and dip-slip events. (3) The range of the stress relief in the buffer section of the borehole with an N–S orientation exceeded those of the other sections. Further geological analysis revealed that higher stress relief was achieved in both boreholes with a N–S orientation and a smaller angle between the borehole direction and the primary fracture orientation (angle BF). An improved numerical calculation model that integrated fracture mechanics and gas reservoir engineering was used in this study; the result showed that an improved CO₂-Frac effect was achieved under a BF angle of 0–21°, in good agreement with the field experiment results. The results of this study can help improve the effectiveness of CO₂-Frac and reduce the occurrence of coal and gas outbursts. Full article