Browse Articles

Alleviation of tannery wastewater toxicity in Spinacia oleracea through application of metal oxide nanoparticles

Abstract Hexavalent chromium [Cr(VI)] rich tannery wastewater has negative impacts on physiological functions and growth of plants. We examined the effectiveness of foliar application of metal oxide nanoparticles including magnesium oxide, zinc oxide and iron oxide in mitigating chromium induced toxicity in Spinacia oleracea under 0%, 50%, and 100% tannery wastewater irrigation levels. The results reveal that chromium stress notably reduced plant growth, chlorophyll content, increased oxidative stress (H 2 O 2 and MDA), electrolyte leakage and build up of Cr both in roots and shoots of plants. The stress also reduced mineral nutrient acquisition including Mg, Fe and Zn. However, foliar application of MgO, FeO and ZnO nanoparticles strengthened the activities of antioxidant enzymes (SOD, POD and CAT) thus resulting in lowered oxidative stress and concentration of Cr within plant body. Application of nanoparticles helped the plants to absorb more mineral nutrients (Mg, Fe and Zn) as well. ZnO nanoparticles proved to be the most effective in mitigating Cr stress in Spinacia oleracia followed by MgO and FeO. This study demonstrates the effectiveness of ZnO NPs along with MgO and FeO in preventing Cr-actuated pressure in degraded conditions.

Numerical simulation of effective dielectric constant of MXene films

MXenes are two-dimensional carbides and nitrides that are relatively simple to manufacture. Even when very thin and flexible, their films can replace metals in many devices, such as electromagnetic shields and antennas, offering excellent performance. The lack of models for predicting their nanostructure-dependent homogenized electromagnetic properties hinders the design and optimization of such devices. Classical linear homogenization models, related to the Maxwell–Garnett approach, are useful for relatively low inclusion volume fractions and the dipolar field approximates the inclusion field well. Neither of these assumptions holds well for MXenes, which can be treated as layers of high-aspect-ratio conducting flakes. A numerical linear homogenization model and an analytical model useful for understanding the effects of the MXene nanostructure on the effective dielectric constant are presented. Numerical estimates are obtained using integral equations for the induced charges on the surfaces of MXene flakes. Parametric studies over varying aspect ratios, inter-flake spacing, and stacking configuration reveal that interleaved stacking can yield higher dielectric enhancement. The effective permittivity increases significantly with increasing aspect ratios in a linear fashion. The findings are consistent with experimental reports of high permittivity in MXene-based composites and offer design insights for engineering high-dielectric constant nanomaterials for electromagnetic interference shielding and communication applications.

Interpretable vocal tract and respiratory inversion via physics-informed neural operators

Near-field thermal radiation between deep subwavelength membranes driven by corner and edge modes

We demonstrate that the thermal radiation between deep subwavelength membranes of silicon carbide (SiC) exhibits a maximum enhancement over that of infinite SiC surfaces separated by the same vacuum gap. Based on fluctuational electrodynamics, we show that this enhancement occurs at a separation distance of 200nm and increases for thinner and colder membranes. This peak arises from the dominant contribution of electromagnetic modes localized at the corner and vertical edges of sufficiently thin membranes, which enable a strong coupling of surface phonon-polaritons appearing along their top and bottom surfaces. These resonant corner and edge modes effectively extend the emission cross-sectional area of the membranes over their geometrical one and, therefore, amplify their thermal radiation. For 10-nm-thick membranes of SiC at 300 K, the thermal conductance reaches 54pWK−1, which yields a maximum enhancement of 4.5 over the value for infinite SiC surfaces. Our findings, thus, reveal that the regime of near-field thermal radiation driven by corner and edge modes emerges and is optimized in deep subwavelength membranes separated by intermediate distances.

Seismic performance of weak-axis steel beam-to-column connections with a T-adapter

Global modeling and performance analysis of a water-fueled radio-frequency gridded ion thruster

This study presents a global model analysis of a water-fueled gridded ion thruster powered by a radio-frequency inductive coil. A comprehensive reaction set is developed to capture the complex plasma chemistry of water, including the formation and ionization of secondary neutrals generated through dissociation and neutral–wall recombination reactions. The global model solves coupled particle and energy balance equations to predict plasma properties and thruster performance as a function of operating parameters, such as the input radio frequency power and the propellant mass flow rate. The results demonstrate that while water exhibits a greater discharge complexity than xenon, the dissociative pathways contribute only marginally to the formation of light ions, such as H+ and H2+. The discharge is instead dominated by heavier ions, such as H2O+, O+, and OH+, which contribute to meaningful thrust production. Compared with xenon (for a 12-cm diameter thruster studied here), water exhibits higher electron temperatures and an enhanced coil–plasma power transfer efficiency, although the propellant mass utilization efficiency and the thrust-to-power ratio are lower. A thrust performance analysis reveals that water can achieve a competitive thrust and specific impulse at higher input powers, establishing its viability as an alternative propellant. Overall, the model provides a robust foundation for the development of future water-fueled electric propulsion systems and addresses a critical gap in general low-temperature water plasma research.

Thermal insulation performance and environmental assessment of vermiculite and agricultural residue based composites for the Kahramanmaras climate

Abstract Thermal insulation plays a crucial role in improving energy efficiency in buildings, particularly in regions with high residential and industrial energy demand. However, conventional petrochemical-based insulation materials raise significant environmental concerns, highlighting the need for sustainable and renewable alternatives. In this study, bio-based composite insulation materials were developed using locally available agricultural residues—stubble, sunflower stalks, corn cobs, corn stalks, and olive pits—incorporated into a vermiculite–epoxy resin matrix. The developed composites exhibited low thermal conductivity values of approximately 0.041 W/mK, comparable to that of expanded polystyrene, while demonstrating enhanced fire resistance due to the presence of vermiculite. Life cycle assessment and experimentally based CO₂ savings analyses revealed substantial reductions in both embodied and operational carbon emissions. The utilization of agricultural waste not only prevents open-field burning but also reduces environmental impacts and supports local economies. Statistical analysis using ANOVA confirmed that the type of agricultural residue significantly influences the thermal and mechanical performance of the composites. Overall, the results demonstrate that the proposed bio-based composites provide a balanced combination of thermal, mechanical, and fire-resistant properties, offering a sustainable, cost-effective, and regionally adaptable solution for energy-efficient building insulation, particularly in climatic conditions similar to those of Kahramanmaras, Turkey.

Understanding in-chamber plasma behavior using a dimensionally scaled gridded ion thruster in three-dimensional kinetic particle-in-cell simulations

We investigate facility effects on a reduced-scale gridded-ion-thruster plume using a fully kinetic, three-dimensional particle-in-cell/Monte Carlo collision solver coupled with a direct simulation Monte Carlo neutral background. This approach enables detailed examination of key plasma processes governing beam neutralization and wall interactions under ground-test conditions. We find that inelastic electron cooling is essential for achieving a physically consistent, neutralized beam. Increasing the background pressure enhances ion–neutral collisions, leading to more charge- and momentum-exchange events that reduce ion mean energies, broaden the beam, and increase sidewall losses. Inelastic processes flattens the potential, sustains quasi-neutrality, and preserves beam collimation farther downstream. Single-particle trajectory analyses show that primary electrons undergo mixed escape and temporary trapping, while low-energy post-inelastic electrons remain confined, sustaining the neutralization cloud. Sheath diagnostics reveal that at the beam dump, classical Child–Langmuir and Hutchinson models underpredict the sheath length due to residual electrons, while near the sidewall, the sheath is truncated by beam-sheath interference within the compact domain. Current-flow analysis indicates that higher background pressure conditions yield lower beam energies and increased sidewall currents.

Lone pair localization governs ferroelectric stability and excitonic properties in lead free halide perovskites

Effectiveness of fluorine termination at nitrogen vacancies inside gallium nitride crystals based on first-principles calculations

Nitrogen (N) vacancies inside gallium nitride (GaN) crystals can scatter carriers and degrade the performance of GaN-based devices. Hydrogen (H) termination is an effective approach for eliminating defect levels in Si crystals but is less effective for GaN because the latter requires higher processing temperatures, which causes H to desorb more easily. Fluorine (F) is a potential alternative to H owing to its high chemical reactivity and small atomic radius. In this study, first-principles calculations were used to investigate the effectiveness of F termination at N vacancies in GaN crystals. The calculated density of states and the band dispersion diagram indicated that F termination eliminated defect states near the conduction band edge and made the electronic states near the band edges resemble those of intrinsic GaN. These effects were attributed to the bonding of F atoms with Ga dangling bonds. Although H termination also resulted in the bonding of H atoms with Ga dangling bonds, the bonding states remained within the bandgap near the band edges; therefore, defect levels were not eliminated as effectively as with F termination. This behavior was attributed to the larger energy difference between the bonding and antibonding states of Ga–F bonds compared with Ga–H bonds. These results suggest that F termination can eliminate defect levels caused by N vacancies inside GaN crystals and improve the performance of GaN-based devices.

Harnessing multimodal deep representation with dimensionality reducing approach for enhanced intrusion detection system in internet of things networks

3D printing technologies for metasurface fabrication and applications of metasurfaces manufactured by 3D printing processes

Metamaterials are artificial materials engineered to possess extraordinary properties, while metasurfaces represent their two-dimensional counterparts, capable of freely defining desired amplitude, phase, and polarization responses. Metasurfaces exhibit significant potential for miniaturizing, integrating, and multifunctionalizing optical devices. However, traditional micro-nano fabrication techniques face bottlenecks such as difficulties in manufacturing complex three-dimensional structures, poor material compatibility, high costs, and limited functionality. In recent times, the swift progress of 3D printing technology has sparked interest in its utilization for metasurface manufacturing. Noticing its characteristics of free-form fabrication design, multi-material integrated manufacturing, and programmable dynamic structures, 3D printing endows metasurfaces with high precision, low cost, and reconfigurable functionality, establishing it as a core pathway for next-generation metasurface production. This article reviews various 3D printing technologies applicable for fabricating metasurface devices and categorically introduces three application domains of metasurfaces prepared via these technologies. First, it presents the concepts of metamaterials and metasurfaces, as well as the merits of 3D-printed metasurfaces. Second, it elaborates on the characteristics, strengths, and applications of two-photon 3D printing, inkjet printing, and material extrusion 3D printing. Then, it classifies and discusses metasurfaces fabricated using 3D printing for three key application areas: singular beam generation, metasurface invisibility cloaks, and metasurface antennas. Finally, we give a summary and evaluation of 3D-printed metasurfaces.

Ergothioneine promotes osteogenesis and angiogenesis through PI3K/AKT pathway and prevents glucocorticoid-induced osteonecrosis of the femoral head

Enhanced multiple pulses incubation of high-repetition-rate femtosecond laser via seed guidance

Multiple pulses incubation based on defects accumulation in laser processing can reduce material ablation threshold and improve machining accuracy, but the randomness of the laser-induced defects leads to unstable incubation. Here, the enhanced multiple pulses incubation strategy of a high-repetition-rate femtosecond laser via seed guidance is proposed to improve machining accuracy. The stable multiple pulses incubation is attributed to a pre-designed seed at a laser processing starting point and a high-repetition-rate femtosecond laser being used. A defect called seed is first prepared on the substrate at a high laser fluence, which significantly increases the absorption of subsequent laser pulses energy. Taking the seed as the starting point of laser processing, subsequent pulses can realize laser ablation at a much lower laser fluence and create new seeds. With the multiple pulses irradiation of the high-repetition-rate femtosecond laser, the stable incubation is finally realized by forming cascade seeds along the scanning path. The material ablation threshold is significantly reduced via the enhanced incubation effect. At a lower laser fluence, the fabricated size is reduced from ∼2.5 to ∼0.7 μm on a silicon substrate. Using this strategy, high-performance reflection grating and a superhydrophobic functional surface are fabricated on silicon substrates. Meanwhile, this strategy can also be extended to transparent material processing.

Sex-specific influence of maturity status on jumping performance in adolescents: a cross-sectional study

Reducing the field emission energy spread of metal tip by tailoring the barrier shape

Finding alternative ways to reduce the field emission energy spread is highly significant for advancing high monochromatic electron sources. This work is proposed to utilize the fractional barrier shape of the metal tip structure, induced by the field concentration effect, to suppress the energy spread. Simulations indicated that the tip radius plays the most important role in the barrier shape among the geometrical parameters of the metal tip field emitter. As the tip radius decreased from 50 nm (where the barrier can be approximated as triangular) to 0.5 nm, the theoretical minimum of full width at half maximum (FWHM) of the energy spread at room temperature was reduced from ∼0.165 to ∼0.153 eV due to the fractional barrier shape. With further consideration of quantum confinement effect, this value could be reduced to ∼0.131 eV. The optimal tip radius for obtaining the minimum FWHM under an applicable emission current ranging from 1 to 100 nA was ∼1 nm. All results present the concept of modulating field emission electron energy spread by tailoring the barrier shape, which is useful for developing high monochromatic electron sources.

A Robust Lemuria Framework for efficient crop prediction

Raman spectroscopy for thermal transport characterization: Principles, techniques, and applications

Raman thermometry converts temperature-dependent spectral shifts into quantitative temperature fields, enabling noncontact measurement of heat transport across a wide range of materials and length scales. This Tutorial presents a unified and practical framework that couples heat-diffusion physics with spectroscopic temperature readout in steady-state and transient regimes. The governing heat equations are developed explicitly for experimentally relevant geometries, including supported and suspended films, multilayer structures, granular media, and particle-laden composites, allowing readers to adapt the models to specific sample structures and boundary conditions. The Tutorial also provides detailed methodological guidance for Raman thermometry in biological and soft-matter systems, addressing experimental configurations and heat-transport considerations in hydrated and heterogeneous environments. A key distinction of this work is its unified treatment of phonon-mediated and photon-mediated heat transport. Representative case studies demonstrate the extraction of intrinsic nanoparticle and interfacial thermal properties from composite measurements and the experimental quantification of near-field radiative heat transfer in densely packed nanoparticle assemblies. Together, these elements establish Raman thermometry as a versatile and quantitative platform for nanoscale thermal characterization across solid-state, granular, and biological systems.

Future-aware blood glucose forecasting using knowledge distillation with transformer-based sequence-to-sequence models

Mitigation of communication blackout with in-plane magnetic thin films

The communications blackout problem encountered by objects rapidly traveling in atmosphere can be mitigated via the application of magnetic fields. Traditional (electro-)magnets used to generate strong out-of-plane fields to magnetize plasma sheaths can be large and heavy, limiting the benefits of the approach. This article investigates the potential use of magnetic material sheets magnetized in-plane to reduce material size requirements and make use of the material’s natural shape anisotropy. Via frequency bandwidth analysis, the existence of open communication bands due to applied in-plane magnetic fields is revealed. Numerical solvers are formulated to compute (i) the varying B fields applied in 3D space from source magnetization regions and (ii) signal attenuation through magnetized plasmas. Performing three numerical studies, it is found that the sizes and locations (in frequency space) of opened windows depend on the plasma profile, the transmitter location, and the material shape, and the magnetic configurations, which offer the greatest reduction in signal attenuation, can often be unintuitive. In addition, it is shown that it is possible to use arrays of smaller magnetic elements to emulate the performance of bulk material, enabling the use of modern thin-film magnetic materials. The presented analysis and numerical studies show that thin-film magnets are expected to be able to open windows to overcome communication blackout.