Search Results (16,809)

Al_0.2CoCrFeNi-5%WC high-entropy alloy (HEA) composites were fabricated via spark plasma sintering at temperatures ranging from 900°C to 1050°C, and the effects of sintering temperature on phase constitution, microstructure, and mechanical properties were systematically investigated. The results show that all composites consist predominantly of an FCC matrix, WC, M₂₃C₆ and M₆C carbides. With increasing sintering temperature, interfacial reactions are promoted, leading to the progressive consumption of WC and an increase in carbide content. The composite sintered at 1000 °C achieves the optimal combination of properties, with a relative density of 96.8%, a yield strength of 468 MPa, an ultimate compressive strength of 1871 MPa, and a fracture strain of 43.6%. The outstanding strength–ductility synergy originates from near-full densification, robust interfacial bonding, and multiple carbide strengthening mechanisms. Excessively high sintering temperature (1050 °C) results in reinforcement coarsening and degradation of mechanical properties. Full article

Electrospun sulfonated polyketone (PK) nanofiber membranes were prepared to investigate the sulfonation-time-dependent structure–property relationships of hydrocarbon-based polymer electrolyte membranes for PEMFC (Polymer Electrolyte Membrane Fuel Cell) applications. NaCl addition to the electrospinning solution increased solution conductivity and enabled the formation of uniform PK nanofibers with an average diameter of approximately 270 nm. Subsequent sulfonation introduced sulfonic-acid-related groups into the PK nanofiber framework, and the resulting membrane properties were strongly governed by sulfonation time. Among the tested membranes, PK-NC16 exhibited the highest proton conductivity of 0.107 ± 0.031 S cm⁻¹ and an ion exchange capacity of 2.82 m_eq g⁻¹, exceeding or comparable to those of Nafion 115 under the tested conditions. FTIR-based analysis indicated that the relative sulfonation index increased up to 16 h, whereas extended sulfonation for 24 h generated additional sulfone/sulfonate-related bands, suggesting possible side reactions or structural changes under prolonged acid treatment. The high water uptake of PK-NC16 enhanced proton transport but also revealed a hydration-sensitive polymer network, as reflected by a voltage degradation rate of approximately −590 μV h⁻¹ during a 100 h short-term stability constant-current test. These results demonstrate that sulfonation time is a key parameter controlling the balance among ionic functionality, hydration, mechanical response, proton conductivity, and PEMFC-relevant single-cell performance in electrospun PK nanofiber membranes. Full article

This research analyzes the wavy, axisymmetric flow of a Ree–Eyring non-Newtonian nanofluid, infused with motile microorganisms, within a porous, tapered cylindrical channel under a transverse magnetic field. This investigation presents a theoretical framework that may inform the improvement of energy efficiency and thermal management in biomedical engineering applications, such as drug delivery systems and microfluidic biosensors. The work provides an extended insight by a contribution to the evaluation of entropy generation, explicitly considering the influence of motile microorganisms, thereby bridging a gap in the existing literature. The comprehensive physical model further incorporates the combined effects of Joule heating, viscous dissipation, nonlinear thermal radiation, and chemical reactions. Methodologically, the governing nonlinear equations of the system were rendered tractable under long-wavelength and low-Reynolds-number assumptions and subsequently solved using the numerical Runge–Kutta–Fehlberg technique. The key conclusion is that, based on the present numerical model, careful selection of magnetic field strength and microorganism motility parameters may reduce irreversible energy losses, potentially improving the net usable work in advanced nanofluid transport systems for biomedical applications, subject to experimental validation. The most significant finding reveals that the magnetic field serves as a dual-purpose control parameter: increasing its strength boosts total entropy generation by 20–30% while simultaneously raising the Bejan number, confirming heat transfer as the dominant irreversibility mechanism in the system. Additionally, nanoparticle concentration diminishes substantially with elevated chemical reaction rates and Schmidt numbers, while microorganism density is highly sensitive to the Péclet number, which causes flow disruptions. Full article

Background/Objectives: Gallic acid (GA) is a naturally occurring polyphenol with reported antioxidant and anticancer properties. This study investigated whether GA enhances carboplatin (CARB)-associated anticancer activity in HeLa cervical cancer cells through mechanisms related to oxidative stress, mitochondrial dysfunction, apoptosis, and cell cycle dysregulation, while comparatively evaluating cytotoxicity in HaCaT cells. Methods: The effects of GA and CARB, individually and in combination, were evaluated using cell viability assays, apoptosis and cell cycle analyses, intracellular reactive oxygen species (ROS) measurements, N-acetylcysteine (NAC)-mediated rescue experiments, mitochondrial membrane potential assessment, reverse transcription–quantitative polymerase chain reaction (RT-qPCR), immunocytochemistry, and three-dimensional (3D) tumor spheroid models. Bioinformatic analyses were performed to explore pathways associated with the observed molecular responses. Results: The GA + CARB combination demonstrated enhanced cytotoxicity and apoptotic activity in HeLa cells compared with either monotherapy, while exhibiting comparatively lower toxicity in HaCaT cells. Combination treatment increased intracellular ROS levels, whereas NAC pretreatment partially reversed ROS accumulation and cytotoxicity, supporting a contributory role of oxidative stress in treatment-associated responses. The combination also induced mitochondrial membrane depolarization, increased G2/M arrest and SubG1 accumulation, and modulated apoptosis- and cell cycle-related gene expression. In 3D spheroid models, GA + CARB reduced spheroid growth and viability and disrupted spheroid integrity more effectively than single-agent treatments. Bioinformatic analyses identified interconnected pathways associated with oxidative stress, apoptosis, and cell cycle regulation. Conclusions: GA may enhance CARB-associated anticancer activity through mechanisms linked to oxidative stress, mitochondrial dysfunction, apoptosis, and cell cycle dysregulation. The incorporation of ROS/NAC rescue experiments and 3D spheroid validation further supports the biological relevance of the observed effects. Nevertheless, these findings remain preliminary and require confirmation in advanced in vivo and translational cervical cancer models. Full article

Blast furnace (BF) ironmaking is a complex multiphase process involving gas–solid flow, heat transfer, chemical reactions, burden movement, and phase transformation under high-temperature conditions. Since many internal states of the blast furnace cannot be directly observed during operation, numerical simulation and mathematical modeling have become important tools for understanding furnace behavior and optimizing operational parameters. This paper reviews recent advances in blast furnace numerical simulation and internal state reconstruction methods. Existing approaches, including packed-bed flow models, cohesive zone reconstruction methods, burden distribution models, and temperature field prediction methods, are summarized and discussed. In addition, the evolution of blast furnace mathematical models from early one-dimensional steady-state formulations to modern three-dimensional multifluid and hybrid simulation approaches is reviewed. Recent developments in computational fluid dynamics (CFD), the discrete element method (DEM), digital twin, and data-driven modeling are also discussed. Compared with traditional simplified models, modern multidimensional and hybrid approaches show improved capability in describing asymmetric furnace inner states, multiphase transport behavior, and operational parameter effects under industrial conditions. However, challenges still remain in achieving computational efficiency, parameter calibration, multiphase coupling, and real-time industrial application. Future studies are expected to focus on the integration of mechanism-based simulation and intelligent data-driven methods to improve prediction accuracy, operational adaptability, and intelligent control capability in blast furnace ironmaking. Full article

Demand for greener and safer chemistries has driven the innovation of bioinspired and enzyme-mimicking catalysts for selective and efficient oxidation and hydrogenation under mild conditions. Natural catalysts, including peroxidases, oxidases, hydrogenases, oxygenases and dehydrogenases, boast remarkable activity, specificity, stability, selectivity, low energy requirements and atom economy. Disadvantages of enzymes, such as poor thermal stability, a narrow operational range, low recovery yield and the expense of purification, are motivating the discovery and design of enzyme substitutes. Several artificial platforms have appeared recently: nanozymes, artificial metalloenzymes, biomimetic metal Complexes, MOFs, atomic catalysts, bioinorganic hybrid systems, among others. These systems aim to replicate key structural and mechanistic features of enzymes while providing greater operational stability, recyclability, and scalability. Recent work has demonstrated the benefit of enzyme mimics in increasing eco-sustainability in reactions such as alcohol oxidation, selective alkane oxidation, waste degradation, catalytic photooxygen activation and biomass waste conversion. Similarly, biomimetic hydrogenation catalysts have shown outstanding activity in asymmetrically hydrogenating chemicals, reducing CO₂ into chemicals, hydrogenation by hydrogen transfer and creating hydrogen through water. Through control of active sites, second coordination sites, defects and electrons/protons in the system, significant gains have been seen in reaction selectivity and frequency of turning over substrate into product. Nanozymes, biohybrid catalysis and artificial catalysts guided by deep learning are further broadening the applications of biomimetic catalysis in oxidation and hydrogenation. The article review aims to provide a summary of the most current progress with bioinspired and enzyme-mimicking catalysts, focusing on catalytic mechanisms, how to design such catalysts, how green chemistry benefits from their development and where further application is likely in the coming years. Full article

Aluminium powder, an energetic material, is prone to thermal runaway upon water exposure under local heat sources, yet the nonadiabatic mechanisms of micron-sized accumulated aluminium powder under localised heating remain unclear. This study employs a proprietary characterisation platform to investigate the effects of particle size, water content, and local heat source power on heat transfer in the dry state and on parameters including induction time, onset temperature, peak heat release rate, and reaction heat during the induction and main reaction phases. In the dry state, decreasing particle size enhances effective thermal conductivity and accelerates temperature rise, whereas elevated local heat source power exacerbates thermal inertia. Under local heating upon water exposure, reduced particle size significantly enhances reactivity; the reaction heat of 2 μm powder reaches 983 J/g, approximately fourfold that of 106 μm powder. Water content exhibits a nonmonotonic effect, with the onset temperature reaching a minimum of 66.4 °C at a water content of 25%, while the reaction heat peaks at 33% water content. Interestingly, increasing local heat source power was found to suppress reaction intensity, and reaction heat at 10 W is one sixth of that at 2.5 W, attributed to rapid product layer densification and the possible steam-film barrier effect shifting the controlling mechanism from chemical to diffusion control. A coupled multifactorial predictive model incorporating the three factors was established with a correlation coefficient R² of 0.92, providing a theoretical basis and practical guidance for hazard assessment and safe storage of aluminium powder. Full article

Aqueous zinc–manganese dioxide (Zn–MnO₂) batteries are undergoing a paradigm shift from traditional ion-insertion mechanisms to a reversible deposition/dissolution process. By leveraging a two-electron transfer (Mn²⁺/MnO₂), this electrolytic system achieves a high theoretical capacity of 616 mAh g⁻¹ and a theoretical operating voltage of 1.99 V. However, the accumulation of dead Mn, electrically isolated inactive phases, and dynamic interfacial pH fluctuations remain critical barriers to cycle life and practical energy density. This review systematizes a trinitarian strategy to overcome these bottlenecks, focusing on interfacial engineering, redox mediator-assisted recovery, and advanced electrode architectures. We evaluate how anion engineering and pH-buffering stabilize reaction pathways, and how diverse mediators (e.g., halogens, metal ions, and organic molecules) chemically rescue inactive manganese. Furthermore, we examine the integration of 3D carbon networks and low-cost hybrid electrodes to sustain high-areal-capacity deposition. To elucidate these complex mechanisms, we highlight multiscale analytical approaches combining synchrotron X-ray techniques and density functional theory (DFT). Finally, we outline a roadmap for applications ranging from grid-scale flow batteries to flexible wearable electronics. This work provides a comprehensive perspective on realizing sustainable, safe, and high-performance zinc-based energy storage. Full article

Aqueous magnesium-ion batteries (AMIBs) are promising for next-generation energy storage technologies due to their high safety, low cost, high theoretical energy density, and environmental friendliness. In particular, manganese-based oxides have attracted much attention due to the abundant resources, high theoretical capacity, and environmental friendliness. This paper provides a comprehensive overview of manganese-based oxide cathode materials for AMIBs, including the crystal structure, electrochemical performance, optimization strategies, and electrode reaction mechanisms. Meanwhile, recent research progress of AMIB full cells based on Mn-based oxide cathode materials is summarized. Finally, the challenges and future perspectives of Mn-based oxide cathode materials for AMIBs are discussed. This review will provide a valuable reference and source of inspiration for future research of manganese-based oxide cathode materials for AMIBs. Full article

Silicone rubber is an important external insulating material for composite bushings, composite insulators, and other power equipment. During long-term service, it is inevitably exposed to coupled environmental and electrical stresses, such as elevated temperature, moisture ingress, strong electric fields, and partial discharge, which may lead to hydrophobicity loss, surface chalking, crack propagation, and particle shedding. To reveal the microscopic degradation mechanism of silicone rubber under complex operating conditions, a molecular model of methyl vinyl silicone rubber was constructed using Materials Studio. A stable silicone rubber molecular structure was obtained through crosslinking, geometry optimization, and ensemble relaxation. Subsequently, a reactive molecular dynamics simulation system under coupled temperature–humidity–electric field conditions was established using LAMMPS and the ReaxFF reactive force field. Different temperature gradients, electric field intensities, and aging–recovery stages were designed to investigate the degradation behavior of silicone rubber. The evolution of the maximum carbon content, maximum silicon content, carbon-containing decomposition products, and typical small-molecule products, including H₂, H₂O, CH₄, C₂H₂, C₂H₄, and C₂H₆, was statistically analyzed. In addition, atomic trajectory tracking was performed to clarify the processes of methyl group detachment, Si-O bond cleavage, water molecule participation, and molecular chain reconstruction. The results show that high temperature mainly promotes methyl group detachment from side chains and fracture of the siloxane main chain, while a strong electric field accelerates the decomposition process and induces the transformation of long siloxane chains into shorter chains. Water molecules can react with broken siloxane chains to form hydroxyl-containing structures, making the structural degradation partially irreversible. The degradation process of silicone rubber under coupled temperature–humidity–electric field stress can be summarized as side-chain detachment, main-chain scission, water-assisted reactions, free-radical recombination, and local molecular aggregation. This study provides a molecular-level theoretical basis for aging mechanism analysis, condition assessment, and lifetime prediction of composite external insulating materials. Full article

Many sectors that sustain humanity’s daily life and wellbeing contribute to the occurrence and accumulation of organic micropollutants (OMPs) in the environment, making them a global concern. This manuscript presents an appraisal of existing scientific literature on removal of OMPs from water by non-thermal plasma-ozonation (NTPO) synergy with specific attention on phenolics, pesticides and herbicides and organic dyes. An overview of non-thermal plasma (NTP) degrading agents in gas and aqueous phases has been given, complemented with diagnostic systems and reactive species detection methods. A scrutiny of reactor systems and their influencing operating parameters has also been discussed. For the analysed types of OMPs, the kinetics, reaction mechanisms and the synergistic degradation effects have been explored. Several studies showed NTPO and NTP/other process synergy resulting in higher degradation efficiency than the individual processes. Most removal reactions followed pseudo-first-order and second-order kinetics while the mechanistic breakdown mainly involved the action of the nonselective OH radical. This scientific critique brings to light utilisable data, provides novel insights on NTPO of OMPs, unveils science gaps for further investigation and presents a wide spectrum of points to consider in plasma water research on OMPs. Full article

The present work reports on the microstructural and micro-mechanical characterization of Ti-Nb-HA-based composites. The composites were prepared via a spark plasma sintering (SPS) consolidation process. The effect of two distinct levels of hydroxyapatite (HA) content (e.g., 10 and 20 wt.%) on the microstructural and micro-mechanical properties were investigated via in situ micro-pillar compression, and the results were compared against a sole Ti-Nb composite. The microstructure of the composites was composed of parent Ti and Nb grains, together with the reaction products; due to the decomposition of HA, there was a rise in different biocompatible phases. The Vickers hardness of the composite was sensitive to applied loads due to the presence of pores and voids, which was foreseen to be beneficial when the composite was used as an implant, according to the literature. The addition of 20 wt.% HA causes a decrease in hardness to 990 HV, compared to 1109 HV for 10 wt.% HA and 1275 HV for sole Ti-Nb. The addition of HA into Ti-Nb also lowers the compressive strength from 553 MPa for Ti-Nb to 189 MPa for Ti-30Nb-20HA. This was accompanied by a reduction in the elastic modulus, from 130 GPa for Ti-Nb to 29 GPa for Ti-30Nb-20HA. The deformation mechanism was ductile-dominated in all cases, with the presence of a quasi-brittle nature for HA-containing composites. Full article

Extracellular vesicles (EVs), particularly small extracellular vesicles (sEVs), are lipid bilayer-delimited particles involved in intercellular communication through the transfer of proteins, lipids, and nucleic acids; many products and studies in aesthetic medicine refer to these preparations as exosomes, although endosomal origin is not always demonstrated. This review examines current evidence on the mechanisms, clinical effectiveness, safety, therapeutic applications, and regulatory challenges of EV- and sEV-based interventions, complemented by an exploratory qualitative assessment of physicians’ perceptions regarding clinical implementation. A narrative review of studies indexed in Scopus and PubMed was conducted with emphasis on skin rejuvenation, hair restoration, wound healing, pigmentation disorders, and inflammatory dermatoses, and responses from 12 aesthetic physicians in Colombia were analyzed qualitatively. Available evidence suggests that EVs/sEVs may promote extracellular matrix remodeling, angiogenesis, immunomodulation, and tissue repair, with potential benefits across several aesthetic and regenerative indications. However, the literature remains heterogeneous and limited by variability in biologic sources, isolation and administration protocols, insufficient high-quality clinical trials, and unresolved regulatory issues. Reports of adverse reactions linked to unapproved products marketed as exosome-based formulations further highlight the need for stronger oversight. EVs, particularly sEVs, often referred to as exosomes in the aesthetic literature, remain a promising therapeutic platform, but safe clinical integration requires rigorous validation, technical standardization, and robust regulatory frameworks. Full article

To investigate the corrosion resistance and deterioration mechanism of cast-in situ concrete incorporating iron ore tailings aggregate (IOT), specimens with IOT replacement ratios of 0%, 30%, and 50% were exposed to distilled water, endogenous Cl⁻-SO₄²⁻ corrosion, exogenous Mg²⁺-SO₄²⁻ corrosion, and endogenous-exogenous coupled corrosion. The evolution of mass, size, compressive strength, and flexural strength was evaluated, while Nuclear Magnetic Resonance (NMR), Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS), X-ray Diffraction (XRD), and Thermogravimetric Analysis/Derivative Thermogravimetry (TG/DTG) were used to characterize pore structure and phase transformation. Results show that distilled water causes limited variation, whereas exogenous and coupled corrosion accelerate product accumulation, size expansion, pore coarsening, and strength degradation. Under exogenous Mg²⁺-SO₄²⁻ corrosion, the peak compressive strengths of specimens with 0%, 30%, and 50% IOT reach 43.30 MPa, 45.60 MPa, and 46.93 MPa, respectively, with the 50% IOT specimen showing an 8.38% increase compared with the specimen without IOT. TG/DTG results show that the Ca(OH)₂ related mass loss decreases from 5.42% under distilled water immersion to 4.37% under exogenous Mg²⁺-SO₄²⁻ corrosion, confirming calcium consumption during sulfate–magnesium attack. Microstructural characterization reveals that sulfate reaction, chloride binding, and Mg²⁺-induced decalcification jointly promote the formation of gypsum, ettringite, Friedel’s salt, magnesium silicate hydrate (M-S-H), and magnesium-associated corrosion products. Overall, 30% IOT provides better pore refinement and mechanical stability under endogenous and exogenous corrosion, whereas 50% IOT improves residual skeleton support under coupled corrosion. These findings provide guidance for durability design and sustainable utilization of IOT aggregate in cast-in situ concrete. Full article

Traditional electro-Fenton systems for chlorinated antibiotic wastewater suffer from low mineralization, catalyst deactivation, and secondary pollution caused by chloride ions. In this work, nitrogen-functionalized graphite felt cathodes were synthesized by electrodeposition-pyrolysis. Pyridinic N and graphitic N were identified by XPS. The obtained cathodes were employed in a metal-free electro-Fenton system for effective tetracycline (TC) removal and mineralization. The results show that the optimal electrode (N-GF-3) achieved 93% degradation efficiency and 73% mineralization of TC in 60 min, when the optimized conditions (pH = 3 and current density = 20 mA/cm²) were employed. Unusually, with the presence of Cl⁻, the system showed even higher catalytic performance, having a degradation kinetic constant 2.4 times higher than that without chloride. The electrode was also reusable, maintaining a TC degradation efficiency above 90% in the fifth cycle. Based on fluorescence analysis of ·OH, a possible dual-path reaction mechanism is proposed. This mechanism provides new insights into designing advanced oxidation processes for the treatment of complex chlorinated organic wastewater. Nevertheless, the potential formation of chlorinated byproducts requires additional investigation. Full article