Search Results (4,009)

Fracturing-fluid retention caused by capillary trapping and surfactant loss during transport through porous media can impair post-fracturing productivity in tight reservoirs. In this study, a rhamnolipid/isopropanol/limonene/water nanosized dispersed formulation was developed as a biosurfactant-based flowback aid. Pseudo-ternary phase diagrams, dynamic light scattering, surface- and interfacial-tension measurements, contact-angle measurements, porous-medium transport experiments, and sand-packed drainage tests were employed to evaluate the formulation behavior and flowback-aiding performance. The largest optically clear single-phase region was obtained at a rhamnolipid/isopropanol mass ratio of 3:1. The formulation maintained nanoscale hydrodynamic dimensions at NaCl or CaCl₂ concentrations up to 10 g/L, while systems containing ≤80 wt.% water exhibited comparatively stable hydrodynamic sizes during 7 d of aging at 70 °C. The equilibrium surface tension reached 25.87 mN/m at 200 mg/L. After passage through the proppant/rock-powder-packed medium, the formulation retained a surface tension of 32.02 mN/m and produced a water contact angle of 95°, compared with 51.20 mN/m and 67°, respectively, for the rhamnolipid aqueous solution. The maximum relative aiding-drainage enhancement approached 89.2% at 2000 mg/L. These results indicate an association among formulation characteristics, interfacial properties, porous-medium transport behavior, and drainage performance, and support the potential of the rhamnolipid-based dispersed formulation as a flowback-aid candidate under the investigated laboratory conditions. Full article

The one-step deposition of binary and ternary polyelectrolyte complexes (PECs) based on poly(ethyleneimine) (PEI), catalase (Cat), and poly(sodium methacrylate) (PMANa) onto quartz sand microparticles (180 μm average diameter) resulted in the formation of sand/polyelectrolyte/enzyme composites with sorption/degradation properties, demonstrated in both static and dynamic conditions toward a model pollutant (indigo carmine (IC)). Prior to the deposition onto a solid surface, the capacity of the pairs PEI/Cat, PMANa/Cat, and PEI/PMANa/Cat to form binary and ternary PECs was studied by dynamic light scattering. Then, two types of composites were prepared, either by including Cat in the initial mixture of components used to form the composites (sand/Cat-PECs) or by adding Cat after the sand/PEC composite formation (sand/PECs/Cat). The distribution of the enzyme in the formed shell of the composites or onto the external surface played an important role in the subsequent sorption/degradation of IC in the presence/absence of H₂O₂. The newly synthesized sand/polyelectrolyte/enzyme composites could immobilize and degrade dye molecules at high flow rates (2–15 mL/min) in dynamic conditions, demonstrating that this new type of composite represent very promising materials for application in water cleaning. Full article

This study investigates the mechanical properties and strength formation mechanism of loess solidified with a ternary blend of fly ash, lithium slag, and magnesium slag. The mix proportion was optimized using response surface methodology with a Box–Behnken design. Unconfined compressive strength (UCS) tests, digital image correlation (DIC), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were employed for evaluation. The optimal 7-day mix (15.926 wt.% fly ash, 10.158 wt.% lithium slag, and 6.427 wt.% magnesium slag) achieved a UCS of 0.974 MPa, while the 28-day optimum (16.064 wt.% fly ash, 10 wt.% lithium slag, and 2 wt.% magnesium slag) yielded 1.834 MPa. Strength development followed a quadratic nonlinear model at early age, shifting to a linear superposition model at 28 days. XRD and SEM revealed that strength enhancement originates from synergistic pozzolanic and hydration reactions under alkaline activation, producing C-S-H gel and ettringite (AFt) that fill pores and cement soil particles. The ternary system demonstrates effective utilization of industrial solid wastes for loess stabilization. Full article

The development of multifunctional cosmetic creams requires balancing functional performance with consumer acceptability. This study aimed to develop cream formulations containing aloe vera gel, eucalyptus essential oil, and vitamin E. Their relative proportions were optimized using mixture-design methodology. Ten formulations were prepared, and antioxidant activity was evaluated using the DPPH radical scavenging assay. A special cubic mixture model was fitted to the experimental data, followed by numerical optimization. The formulations were further characterized in terms of pH, microstructure, sensory attributes, and microbiological quality during refrigerated storage. Antioxidant activity varied among creams, with significant aloe vera × eucalyptus essential oil and aloe vera × vitamin E interactions. The model showed high explanatory capacity (R² = 93.14%) and predicted an optimum mixture of 30.3% aloe vera gel, 29.3% eucalyptus essential oil, and 40.4% vitamin E. The pH of the creams remained within 4.74–5.18, while most sensory attributes were comparable among formulations. Odor and cooling sensation were formulation-dependent, while willingness to use exceeded 60% for several formulations and reached approximately 71% for BIO8. Microbial counts remained below the applicable quantitative acceptance criterion during the 60-day refrigerated storage assessment, while the specified target microorganisms were not detected under the microbiological methods employed. The findings support further investigation of ternary formulations under formulation and stability conditions relevant to cosmetic use. Full article

With growing attention on renewable resources, hydrogen production as a sustainable alternative to increasingly depleted non-renewable fossil fuels has attracted significant interest. To develop economical electrocatalysts for HER that can replace platinum, this study synthesized a ternary CoFe₂O₄/Fe₂O₃/Co₃O₄-AC (activated carbon) nanocomposite via a urea-assisted one-step hydrothermal method, using water-soluble AC-ONa as a crystal growth regulator. The morphology and structure of the catalyst were thoroughly characterized by SEM, TEM, XRD, and XPS. Electrocatalytic water splitting performance was subsequently evaluated in 1.0 M KOH electrolyte. Results show that the catalyst requires an overpotential of 271 mV at a current density of 10 mA·cm⁻², significantly outperforming single-phase Fe₂O₃-AC (576 mV), Co₃O₄-AC (511 mV), and CoFe₂O₄/Fe₂O₃/Co₃O₄ (291 mV). The Tafel slope is 72.2 mV·dec⁻¹, consistent with the Volmer–Heyrovsky pathway. After a 10 h i-t stability test, the HER current remained essentially unchanged; moreover, after 1000 cyclic voltammetry cycles, the overpotential slightly decreased to 259 mV, demonstrating excellent HER stability. This work establishes a facile one-pot strategy for constructing multicomponent metal-oxide composite materials, in which soluble carbon additives play a key role in guiding interfacial growth. This method is easily scalable and avoids complicated procedures, providing a potential route for designing low-cost, highly active non-noble metal catalysts for alkaline HER. Full article

This study presents the development and comprehensive characterisation of a sustainable 3D-printable cementitious composition in which up to 40 wt.% of Portland cement was replaced by a ternary binder containing oil shale ash (OSA) and metakaolin (MK). Following laboratory optimisation, the developed formulations were successfully transferred to industrial production as pre-blended dry mixes at Sakret Latvia Ltd., demonstrating the feasibility of large-scale manufacturing of printable cementitious materials. Attention was devoted to the characterisation of the raw materials and dry mixtures using particle size distribution (PSD), scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS), and X-ray diffraction (XRD). Two compositions—a reference mixture (REF) and the ternary OSA mixture—were evaluated in terms of printability, mechanical performance, durability, and the influence of the type of sample production. The ternary composition (due to the pozzolanic activity of MK and OSA) exhibited strength development resulting in compressive strength (60.6 MPa) exceeding that of the reference mixture after 90 days of curing (55.3 MPa). Mechanical testing of compression and flexural properties indicated direction-dependent differences between printed and cast specimens. Durability assessment, including capillary water absorption and surface freeze–thaw scaling tests performed using two standardised methods, confirmed frost resistance and the suitability of both mixtures for outdoor applications. The results further indicate that the layered manufacturing process governs moisture transport and direction-dependent mechanical behaviour associated with interlayer interfaces. The developed pre-blended OSA–MK composite represents a promising low-carbon material for industrial 3D concrete printing, combining reduced cement consumption with reliable printability, mechanical performance, and durability. Full article

The joining of solid-state sintered silicon carbide (SiC) was achieved using a novel Si-Ti-Al ternary alloy via vacuum brazing. This study investigates a predominantly non-carbide-dominated interfacial bonding mechanism and the influence of brazing temperature on joint microstructure, mechanical properties, and high temperature reliability. The high Si content promoted the incorporation of Ti into Ti–Si phases within the brazed seam, thereby limiting the amount of Ti available for reaction with SiC. No continuous TiC layer was detected within the spatial resolution of the employed characterization methods. Minor discrete Al₄C₃ precipitates were identified at the interface but did not constitute the dominant bonding phase. Brazing at 1360 °C yielded an optimal microstructure featuring highly regular coral-like eutectic clusters, resulting in a peak room temperature shear strength of 102.8 MPa. The joints also exhibited favorable high temperature reliability, maintaining a shear strength of 58.4 MPa at 1000 °C. Microstructural analysis following thermal exposure revealed partial coarsening of primary blocky phases and interfacial Al₄C₃ precipitates via Ostwald ripening, which contributed to the reduction in high temperature strength. Nevertheless, the robust retention of fine eutectic clusters ensured satisfactory structural stability under thermal loading. This work provides a viable strategy for designing Si-based brazing fillers for high-performance SiC ceramic joining. Full article

Translating adsorption performance from batch experiments to continuous-flow operation is a key step toward practical water-treatment applications. In this study, a laboratory-scale continuous adsorption system based on a water-insoluble β-cyclodextrin-epichlorohydrin (β-CD-EPI) polymer was validated from hydrodynamic, adsorptive, and operational perspectives. Downflow operation caused progressive bed compaction and excessive pressure development, whereas a 90 mm column operated in upflow mobile-bed mode, with visually observed bed expansion, showed comparatively stable pressure-drop behavior at superficial linear velocities below approximately 12 m h⁻¹. Under these controlled high-loading conditions, removal was strongly contaminant-dependent: cyproconazole exceeded 90%, acetaminophen reached 72–77%, hydrochlorothiazide reached 40–65%, ciprofloxacin reached 24–50%, and furosemide remained below 30%. The relative performance for furosemide and hydrochlorothiazide differed from that predicted by previous batch-derived adsorption parameters, demonstrating that batch results cannot be directly extrapolated to dynamic operation. Competitive adsorption in binary and ternary mixtures reduced contaminant removal, while cyproconazole removal decreased from >90% in tap water to 48–55% in secondary-treated wastewater, demonstrating the relevance of the aqueous matrix under the tested continuous-flow conditions. Operational screening tests showed that desorption with 220 mM acetate buffer at pH 4.0 recovered >80% of the retained cyproconazole within 10 min in the tested sequence, followed by a two-stage rinse that restored the operational pH. These preliminary conditions require confirmation through replicated adsorption–desorption cycles under continuous-flow operation. These results identify laboratory-scale hydrodynamic, adsorption, matrix, and regeneration considerations that require confirmation through fixed-condition, long-term testing during subsequent process development. Full article

The paper includes the synthesis and characterization of a new ternary composite electrode material based on MXene (Ti₃C₂T_x), Molybdenum Disulfide (MoS₂), and Cerium Oxide (CeO₂) nanoparticles for supercapacitor applications. The heterostructure was prepared by a hydrothermal technique with a 1:1:1 ratio, ensuring a well-integrated heterostructure. The successful anchoring and uniform distribution of MoS₂ and CeO₂ on the layered MXene matrix were confirmed by structural and morphological analysis using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electrochemical performance measurements such as cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) were used to collectively show that the composite has a higher specific capacitance of 1220 F g⁻¹ at 1 A g⁻¹, good cycling stability of 90, and content retention at 5K cycles. A negative binding energy, calculated using Complementary Density Functional Theory (DFT), shows strong interfacial interaction and the structural stability of the composite. Moreover, the analysis of the Density of States (DOS) showed indicators of metallic-like behavior due to the interaction of Ti-d, Mo-d, and Ce-f orbitals, which largely reduces the energy barrier to the flow of electrons. These findings demonstrate the synergistic nature of high conductivity by MXene, pseudocapacitance by the metal oxides/sulfides, and improved redox performance, and thus make the MoS₂-CeO₂ @ MXene hybrid an attractive target in the next generation of energy storage devices. Full article

The Jiali Fault Zone is one of the key active tectonic structures along the southeastern margin of the Tibetan Plateau and has been widely regarded as the southern boundary structure accommodating the lateral extrusion and eastward escape of the Qiangtang and Sichuan–Yunnan blocks. Assessing its Quaternary activity is important for understanding the tectonic evolution and deformation partitioning of southeastern Tibet. This study focuses on the Yi ong–Zayu segment of the Jiali Fault Zone, using high-resolution stereo imagery from the GF-7 satellite. The ERDAS dense image matching method was applied to generate a dense point cloud and a 0.8 m high-resolution digital surface model. Combining regional remote sensing image interpretation with field surveys, we characterize the geomorphic expression and Quaternary deformation of the Yi ong–Zayu segment. The results show no significant surface displacement along the fault. The alluvial fans are largely preserved, and there are no continuous, co-directional offsets along the tributary channels or river systems. In particular, clear evidence for Quaternary right-lateral strike-slip displacement is absent. Instead, localized normal faults with NW–SE to approximately E–W strikes occur in limited areas. This study focuses on the Yi ong–Zayu segment of the Jiali Fault Zone, using high-resolution stereo imagery from the GF-7 satellite. The ERDAS dense image matching method was applied to generate a dense point cloud and a 0.8 m high-resolution digital surface model. Combining regional remote sensing image interpretation with field surveys, we characterize the geomorphic expression and Qua-ternary deformation of the Yi ong–Zayu segment. The results show no significant surface displacement along the fault. The alluvial fans are largely preserved, and there are no continuous, co-directional offsets along the tributary channels or river systems. In particular, clear evidence for Quaternary right-lateral strike-slip displacement is absent. Instead, localized normal faults with NW–SE to approximately E–W strikes occur in limited areas. These findings indicate that the Yi ong–Zayu segment experienced limited Quaternary deformation and has not functioned as a major boundary strike-slip fault since the Quaternary. Instead, it has been influenced by the rotational extrusion of the southeastern Tibetan Plateau, exhibiting characteristics of regional extensional tectonic activity. The present-day deformation is consistent with a rotation–extrusion model, in which crustal material undergoes clockwise rotation around the eastern Himalayan syntaxis and gradually transfers southeastward toward the Sichuan–Yunnan region due to the obstruction of the rigid Sichuan Basin. Full article

A sequential two-stage chemo-biocatalytic process was investigated for the conversion of D-xylose to furfuryl alcohol (FOL), an important furan derivative widely used in the manufacture of resins, polymers, fuels, and other value-added products. In the first stage, D-xylose was dehydrated to furfural (FAL) in a ternary Betaine:Formic acid:Malonic acid–water (Bet:FA:MA–H₂O) reaction medium. Under the selected conditions, a FAL yield of 65.8% was obtained from 22.5 g/L D-xylose using 15 wt% Bet:FA:MA at 170 °C for 30 min. For the subsequent bioreduction stage, a recombinant Escherichia coli strain co-expressing the aldehyde reductase EutG and glucose dehydrogenase (GDH) was constructed. Using glucose as a co-substrate, EutG–GDH whole cells were able to reduce commercial FAL at concentrations up to 150 mM under the selected conditions of 40 °C and pH 7.5. For the sequential process using the D-xylose-derived dehydration liquor, the acidic reaction mixture was adjusted to pH 7.5 and diluted from 98.7 to 30.0 mM FAL before whole-cell bioreduction. The conditioned 30.0 mM FAL feed was essentially completely converted to FOL within 24 h. These results demonstrate the laboratory-scale feasibility of sequentially combining Bet:FA:MA–H₂O-mediated D-xylose dehydration with EutG–GDH whole-cell FAL reduction after interstage pH adjustment and dilution. Full article

The burgeoning global demand for rare earth elements (REEs), driven by rapid technological advancements, has elevated their strategic significance. As a ubiquitous metallic mineral that crystallizes throughout the magmatic and hydrothermal stages, pyrite can potentially record the history of REE enrichment within magmatic–hydrothermal systems. The Bachu carbonatite-hosted REE deposit in Xinjiang represents a significant rare earth resource base in China. Elucidating its ore-forming mechanism is therefore crucial for understanding regional metallogenesis and guiding future exploration efforts. In this study, pyrite from this deposit is investigated in detail by employing an integrated analytical approach that includes scanning electron microscopy (SEM), electron probe microanalysis (EPMA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) trace-element analysis, and in situ sulfur isotope analysis. Based on textural and petrogenetic relationships observed under microscopy, three distinct types of pyrite are identified: (1) pyrite coexisting with hydrothermal minerals such as barite and celestite; (2) pyrite showing evident replacement textures, despite the absence of direct intergrowth with sulfate minerals; and (3) pyrite displaying neither intergrowth nor replacement textures with sulfates. These textural distinctions, combined with variations in Co/Ni ratios, Co-Ni-As ternary plots, and Co/Sb vs. Se/As systematics, enable a clear discrimination between pyrite formed during the magmatic (Py1) and hydrothermal (Py2) stages. Pyrite from the magmatic stage (Py1) is characterized by positive δ³⁴S values ranging from 0.03‰ to 4.67‰, with a pronounced peak at 1.30‰, which is higher than the mantle δ³⁴S value (~0‰). This sulfur isotope signature suggests that crustal material was involved in the petrogenesis of the Bachu carbonatite. In contrast, pyrite from the hydrothermal stage (Py2) exhibits a bimodal distribution of δ³⁴S values. One group, peaking at approximately +0.93‰, indicates a magmatic sulfur source genetically related to Py1. The other group, however, displays distinctly negative values, with a peak around −4.93‰, which may be attributed to sulfur isotope fractionation processes during mineralization. Notably, barite from the hydrothermal stage exhibits consistently positive and elevated δ³⁴S values, ranging from 10.46‰ to 15.94‰ (average 12.82‰). The contrasting δ³⁴S values compared to the negative Py2 values manifest a clear “Tower Effect,” strongly suggesting that the extensive precipitation of barite was a primary driver of the negative sulfur isotope values observed in the composition of coexisting hydrothermal pyrite (Py2). The pyrite generations also establish a stage-specific link to REE mineralization: Py1 records the reduced magmatic interval of carbonatite differentiation and primary REE preconcentration, whereas Py2 is associated with the barite–celestine–fluorapatite–monazite assemblage of the REE-rich hydrothermal veins and records the later oxidized fluid overprint. By integrating detailed mineralogical and geochemical evidence, this study successfully distinguishes between magmatic and hydrothermal pyrite populations and provides critical constraints on the sources of ore-forming materials in the Bachu carbonatite-type REE deposit. Full article

Severe heavy metal pollution in aquatic environments demands the engineered development of structurally optimized, highly selective adsorbents. Herein, we report the intentional fabrication of a novel ternary MnO₂/NH₂-MIL-101(Fe)/g-C₃N₄ nanocomposite via an integrated in situ interfacial growth pathway. The true architectural novelty of this multi-component assembly lies in utilizing the 3D mesoporous metal–organic framework (MOF) scaffolding to structurally isolate the 2D g-C₃N₄ layers and prevent the self-aggregation of redox-active MnO₂ nanoparticles. Comprehensive characterization via PXRD, FTIR, TEM, Raman, and high-resolution XPS confirmed that this unique interfacial hybridization maximizes the spatial exposure of unblocked chemical binding sites. Batch extraction trials demonstrated a high Pb²⁺ removal efficiency of 99.5 ± 2.7% at an optimized pH of 6.0, yielding a superior maximum monolayer adsorption capacity (q_max) of 431.8 mg.g⁻¹. Competitive selectivity matrices containing co-existing ions (Cu²⁺, Cd²⁺, Ni²⁺, and Cr³⁺) revealed noticeable selectivity toward Pb²⁺ ions, driven by soft Lewis’s acid-base affinities, while background electrolyte tests identified SO₄²⁻ as the most influential competing anion. Non-linear isotherm modeling showed a better agreement with the Langmuir model, suggesting dominant monolayer adsorption on accessible surface sites, while kinetic data followed the pseudo-second-order model. Spectroscopic profiling proved that this heightened performance is dictated by a multi-modal integrated network operating via cooperative inner-sphere Mn-OH complexation, oxygen-vacancy trapping, exocyclic framework amine (-NH₂) chelation, and g-C₃N₄ triazine dative configurations. These findings establish the ternary system as an advanced, highly recyclable benchmark for targeted heavy metal decontamination. Full article

Reducing carbon emissions in concrete production while improving structural performance has become a priority in the transition to carbon neutrality. High-volume fly ash and slag systems significantly reduce carbon emissions. However, their complex hydration interactions alter strength development, rendering conventional empirical strength models inadequate for reliable low-carbon binder design. To overcome this limitation, this study proposes an integrated hydration-mechanism-based framework that links strength prediction with carbon-oriented binder optimization. A unified hydration model is developed based on the coupled evolution of capillary water and calcium hydroxide, enabling a consistent description of cement hydration, slag latent hydraulic reaction, and fly ash pozzolanic reaction in ternary binder systems. A single set of material-specific kinetic parameters is applied across the investigated mixture proportions and curing ages, without recalibration for each mixture. Building on the predicted degree of reaction, a compressive strength model centered on effective reaction contributions is calibrated using 1030 experimental data points encompassing 3–365 days and 2.33–82.60 MPa. Within the calibration database, the model reproduces early-age strength reduction, later-age compensation, and strength crossover behavior induced by mineral admixtures. The strength model is subsequently embedded into a genetic algorithm framework to perform theoretical binder-level low-carbon inverse design under 28-day strength and composition-domain constraints. The optimization results reveal boundary-dominated solutions, with mineral admixture replacement ratios approaching upper limits and a reduced water content contributing to further calculated emission reduction. Because aggregates, paste volume, superplasticizer dosage, and workability are not included, the resulting binder compositions are theoretical candidates rather than complete concrete mixture designs. This work presents a physically interpretable and optimization-ready framework for binder-level low-carbon design within the adopted model domain. Full article

To promote the valorization of red mud (RM), a high-volume industrial solid waste, engineered geopolymer composites (EGC) were developed using a ternary binder comprising ground granulated blast-furnace slag (GGBS), fly ash (FA), and RM. Ten mixtures were designed using a simplex-centroid method, and the effects of binder composition on fresh-state flowability, axial compressive behavior, and axial tensile performance were systematically investigated. The results showed that GGBS was the dominant factor governing compressive strength. The mixture with the highest GGBS content, G50F50R0, achieved a maximum compressive strength of 111.7 MPa. Although RM incorporation reduced compressive strength, the strength remained approximately 70 MPa at an RM content of 30%, while the post-peak brittleness was noticeably mitigated. In tension, an appropriate RM content of 5–15% effectively reduced matrix toughness, enabling pronounced strain-hardening and multiple-cracking behavior through fiber bridging. Consequently, tensile ductility and strain energy density were substantially enhanced, with the ultimate tensile strain reaching up to 6.9%; however, excessive RM addition led to performance degradation. By overlaying multi-objective performance boundaries, an optimized composition range of 40–45% GGBS, 50–60% FA, and 0–8% RM was identified, enabling the simultaneous achievement of high strength, high toughness, and high energy absorption. These findings demonstrate the technical feasibility of using RM to produce EGC and provide a theoretical basis for the high-value utilization of RM. Full article