© The Author(s), under exclusive licence to The Brazilian Society of Mechanical Sciences and Engineering 2025.Uncertainty in the natural frequencies of composite cylindrical shells is typically assessed with parametric models that assume specific probability laws for material and geometric inputs. Here, we propose a fully data-driven, nonparametric alternative based on the orthogonal bootstrap, integrated into a semi-analytical Rayleigh–Ritz framework for shells subjected to axial load and internal pressure. This study makes four key contributions: (1) It introduces the orthogonal bootstrap to the structural dynamics of composite shells, enabling uncertainty propagation directly from empirical samples without prescribing distributions; (2) it provides a head-to-head comparison between the nonparametric approach and a conventional parametric Monte Carlo scheme (Beta-distributed), clarifying the conditions under which each method is most advantageous; (3) it incorporates stress-stiffening effects (geometric stiffness) from axial compression and internal pressure into the Rayleigh–Ritz formulation, enabling probabilistic frequency estimates under combined loading; and (4) it validates the semi-analytical results against a refined finite-element model, demonstrating an order-of-magnitude reduction in computational time with orthogonal resampling. The results reveal that frequency variability is primarily dominated by the radius-to-thickness ratio and fiber elastic modulus, while density predominantly influences mass-driven shifts. The proposed framework offers a transparent, efficient means of quantifying uncertainty in composite shell dynamics without the risk of distributional misspecification, and it can be readily extended to other laminated configurations and loading scenarios.

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.Structural Health Monitoring (SHM) plays a crucial role in ensuring the integrity and longevity of aerospace structures. This study investigates the detectability of structural defects using Lamb waves, focusing on the impact of defect size on wave propagation characteristics. Numerical simulations were conducted on an aluminum plate embedded with a sensor-actuator network, evaluating the interaction of fundamental Lamb wave modes (A0 and S0) with defects of 2, 4, and 8 mm in diameter. Frequency spectrum analysis revealed that larger defects lead to significant energy attenuation, spectral shifts, and mode conversion, particularly influencing the dispersive nature of the A0 mode. Detectability maps derived from FFT energy loss highlight the sensitivity of different sensor locations to damage, demonstrating that defect size and wave scattering influence signal degradation. The findings confirm that Lamb wave-based SHM effectively enables early defect detection and damage quantification. The results support the optimization of sensor placement and excitation frequency selection to enhance defect characterization.

© 2026 The Authors.The use of binder-stabilized fabrics in wet compression molding (WCM) processes may be necessary to maintain fabric integrity and improve the bending stiffness of thick fabric stacks for improved resin management, particularly for unidirectional non-crimp fabrics (UD-NCFs). Therefore, it is essential to characterize the influence of stabilizing binder on the mechanical properties and quality of the final part. In this study, UD-NCF composite panels were manufactured with distinct processing conditions, including binder pre-activation and vacuum application during WCM, and extracted specimens were mechanically tested and microscopically assessed via optical microscopy and X-ray computed tomography. Pre-activation of the stabilizing binder reduced void content within the composite panels, thereby enhancing mechanical properties. Additionally, drawing vacuum for a duration of 20 s reduced the volume of large voids and increased the fiber volume fraction and interlaminar shear strength. This study provides valuable insights into the effects of a stabilizing binder and vacuum assistance on the mechanical properties of binder-stabilized UD-NCF composites.

© The Author(s), under exclusive licence to Springer Nature India Private Limited 2026.Closed-form analytical solutions for displacement, strain, and stress serve as essential benchmarks for validating numerical methods. This work constructs complete function sets that generate two classes of strong solutions to the governing partial differential equations of two-dimensional beams. The boundary conditions are of Neumann type, prescribing displacement derivatives (strains) or equivalently stresses along all surfaces. The proposed framework is demonstrated on orthotropic and isotropic beams, effectively reproducing continuous and discontinuous surface stresses. The results provide a versatile set of benchmark solutions for assessing beam mechanics models.

© 2026 The Author(s).In wet compression molding (WCM), understanding the compaction behavior of infiltrated reinforcement fabrics is essential, as it impacts the microstructure and fiber volume fraction of the finished part. Incorporating binder-stabilized reinforcements may be necessary in WCM to improve material handling and enhance part quality. This research aims to characterize and model the time-dependent compaction behavior of an infiltrated, binder-stabilized carbon fiber unidirectional non-crimp fabric (UD-NCF) through multi-phase experiments, specifically focusing on effects of resin viscosity, stacking sequence, and binder pre-activation. Findings indicate that infiltrated fabric requires lower compaction forces compared to dry fabric, mainly due to the lubrication of tows and stitching, which reduces tow-stitch friction and provides less resistance to tow spreading. Furthermore, compaction forces increase with binder pre-activation across all conditions tested, while the degree of relaxation is reduced. Lastly, the stacking sequence has a minor influence on the compaction response owing to limitations in tow nesting imposed by supporting fibers. Maxwell and fractional Zener models are considered to capture the fabric time-dependent response, with the latter providing an improved fit to the experimental data. This is the first detailed investigation on compaction behavior of infiltrated, binder-stabilized UD-NCFs, offering new and important insights into their complex deformation response.

© The Author(s), under exclusive licence to The Brazilian Society of Mechanical Sciences and Engineering 2025.This study proposes a quasi-2D composite beam finite element based on a global–local superposition, combined with an interlaminar damage model, with the aim of accurately assessing, predicting, and evaluating delamination in composite laminates, as well as structural health, under both environmental and operational conditions. The changes in the mechanical properties of the laminated material induced by delamination are computed as a function of the interfacial displacements The main advantage of this formulation lies in its computational efficiency, ensured by the global-local superposition of displacement fields, which not only captures the expected zig-zag behavior of stresses and displacements, but also makes the total number of degrees of freedom (DOFs) independent of the number of layers. This is achieved because the local DOFs, whose quantity is related to the interpolation functions in each layer, are efficiently eliminated through the application of boundary conditions and the CZ0continuity criteria, allowing the displacements and stresses to be determined exclusively by the DOFs used in beam elements. In this context, the finite element (FE) formulation is applied only to mode I delamination (opening) with a bilinear loading–unloading curve, considering cases of different interlaminar thicknesses, loading conditions, and environmental situations. It is worth noting, however, that the new proposal enables the inclusion of other delamination modes as well as formulations based on different forms of stress–displacement curves for loading and unloading. Finally, the proposed beam element provides a concise, detailed, and efficient analysis of laminated structures of varying complexity, delivering relevant and consistent results regarding structural damage behavior. Moreover, it enhances damage predictability, contributes to structural health monitoring, and improves design efficiency in composite structures, since the algorithm is simple to implement, requires low computational cost, and offers results comparable to commercial software for two-dimensional analyses, making it an excellent economic and effective option.

© 2025 The Author(s)Assessing the bending response of infiltrated reinforcement fabrics is crucial in wet compression molding (WCM) as it affects macroscopic wrinkling. Binder-stabilized fabrics may be used in WCM to improve handleability and reduce defects, necessitating their characterization. This study examines the bending behavior of an infiltrated binder-stabilized carbon fiber unidirectional non-crimp fabric (UD-NCF), focusing on the effects of viscosity, loading rate, and binder pre-activation. Infiltration reduces bending stiffness compared to dry fabric owing to lubrication and lower tow-stitch friction, while higher loading rates increase bending stiffness for all considered conditions. Moreover, binder pre-activation increases fabric stiffness by enhancing tow-stitch cohesion and friction. As the first investigation on infiltrated binder-stabilized UD-NCF bending, this work advances understanding of the complex bending response.

© 2026 The Author(s)In this computational study the explicit interaction of Bi and Te with (111), (110), and (100) platinum surfaces was investigated, focusing on structural and electronic characteristics of the studied systems as a function of the adsorbate coverage. For Bi/Pt systems, good agreement was found between calculated results and previously published data. At all coverages adsorbed Bi or Te atoms interact repulsively. At coverages close to half a monolayer the structure of the adlayers on more open Pt(110) and (100) surfaces is defined by the geometry of the substrate, while on densely packed Pt(111) the regular pattern breaks and adsorbed Bi or Te layers become more disordered, as experimentally reported for Bi. Additionally, whereas the downshift on the d-band centre of Pt atoms in contact to the adatoms weakens the Pt-Bi(Te) bond, the depolarization of the adlayer contributes to the stabilization of the adatom-adatom interaction within the adlayer. Obtained results evidence that Bi and Te adlayers supported on Pt cannot be treated as a mere combination of their parts and, instead, must be considered as unique materials with properties different from their parent systems.

This journal is © The Royal Society of Chemistry, 2026In this work, the use of a mechanically chopped laser beam as the excitation source of an ambient tip-enhanced Raman (TER) spectrometer is studied. In the experiments, all macroscopic variables are identical except the nature of the laser excitation, with the objective to increase the time resolution of this technique toward the (sub)millisecond time scale. A (sub)monolayer of thiophenol adsorbed on the Au(111) surface was analyzed in terms of the stability of the TER signal as a function of time and laser power. The results show that TER spectra with chopped excitation have similar stability, sensitivity, spectral resolution, peak position and peak width and signal-to-noise ratio, as the ones recorded by employing continuous wave (cw) excitation. The proposed methodology allows to successfully overcome the trade-off of spectral and temporal resolution given by ps or fs excitation and increases the pulsed laser power tolerated by the tip/sample junction and the adsorbed molecules before degradation occurs. This work opens the possibility to perform ambient TER measurements with a temporal resolution on the millisecond scale at spectral resolution and SNR, comparable to the one achieved with cw excitation without modification of the standard detection system of the TER set-up.

© The Author(s), 2026. Published by Cambridge University Press.In this study, we explore the effect of basis functions on the performance and convergence of the Galerkin projection-based reduced-order model (ROM) in the minimal flow unit of Couette flow. POD (proper orthogonal decomposition) modes obtained from direct numerical simulation, and controllability and balanced truncation modes from the linearised Navier–Stokes equations (LNSEs) with different base flows (laminar base flow and turbulent mean flow) and an eddy viscosity model are considered. In the neighbourhood of the laminar base state, the ROMs based on the modes from the LNSEs with the laminar base flow and molecular viscosity are found to perform very well as they are able to capture the linear stability of the laminar base flow for each plane Fourier component only with a single degree of freedom. In particular, the ROM based on the balanced truncation modes models the linear dynamics involving transient growth around the laminar base flow most effectively, consistent with previous studies. In contrast, for turbulent state, the ROM based on POD modes is found to reproduce its statistics and coherent dynamics most effectively. The ROMs based on the modes from the LNSE with turbulent mean flow and an eddy viscosity model performs better compared with any other ROMs using the modes from the LNSE. These observations suggest that the performance and convergence of a ROM are highly state-dependent. In particular, this state dependence is strongly correlated with the information and dynamics that each of the basis functions contain. Discussions supporting these observations are also provided in relation to the flow physics involved and the form of coherent structures in Couette flow.

© 2025 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.This study evaluates the potential of resolvent analysis to model broadband trailing-edge (TE) noise generated by a turbulent boundary layer over an airfoil. A compressible resolvent formulation is applied to the mean flow obtained from large-eddy simulation (LES) of a NACA0012 airfoil at a chord Reynolds number of Re = 200;000. The resulting modes are validated against spectral proper orthogonal decomposition of the LES data, enabling direct comparison between a physics-based model and data-driven analysis. We identify regions in the frequency– spanwise-wavenumber spectrum where the flow exhibits low-rank behavior, notably for low Helmholtz numbers and spanwise wavenumbers, coinciding with peak acoustic emissions. In these regions, the leading resolvent mode captures the dominant hydrodynamic and acoustic structures: wave packets on the suction side exploiting the Orr mechanism. The resolvent framework isolates the structures responsible for sound generation from the complete turbulent dynamics and links them to the mean flow, offering a physics-based model suited for noise control. Unlike empirical models requiring full turbulent spectra or high-fidelity simulations with prohibitive cost, the resolvent approach provides a low-order, efficient alternative. These results demonstrate its potential as a foundation for future sensitivity-based design strategies targeting broadband TE noise reduction.

© The Author(s), 2026. Published by Cambridge University Press.A linear theory for unsteady aerodynamic effects of the actuator line method (ALM) is developed. This theory is validated using two-dimensional ALM simulations, where we compute the unsteady lift generated by the plunging and pitching motion of a thin aerofoil in uniform flow, comparing the results with Theodorsen’s theory. This comparison elucidates the underlying characteristics and limitations of ALM when applied to unsteady aerodynamics. Numerical simulations were conducted across a range of chord lengths and oscillation frequencies. Comparison of ALM results with theoretical predictions shows consistent accuracy, with all Gaussian parameter choices yielding accurate results at low reduced frequencies. Furthermore, the study indicates that selecting a width parameter ratio of ε/c (the Gaussian width parameter over the chord length) between 0.33 and 0.4 in ALM yields the closest alignment with analytical results across a broader frequency range. Additionally, a proper definition of angle of attack for a pitching aerofoil is shown to be important for accurate computations. These findings offer valuable guidance for the application of ALM in unsteady aerodynamics and aeroelasticity.

© 2025, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.High-speed-jet turbulent mixing noise remains a challenging problem, and here we aim to reduce it using a wavepacket-cancellation strategy. This approach is enabled by the recently developed resolvent-based estimation and control framework, which uses near-nozzle sensors to detect noise-generating wavepackets and suppress them via actuation. This paper presents three main results toward this larger goal: (i) data-driven estimation for a Mach 1.5 supersonic jet using large-eddy simulations to identify coherent structures and inform sensor-target placement; (ii) resolvent-based estimation for the linearized jet, which achieves reasonable accuracy in reconstructing relevant flow features from limited sensor data; and (iii) preliminary resolvent-based control for the linearized jet, demonstrating a 34% reduction in the root mean square of streamwise-momentum fluctuations using only one sensor and one actuator. These findings demonstrate the potential of the resolvent-based framework for mitigating noise-generating wavepacket structures in supersonic jets and provide an important foundation for future computational and experimental investigations.

© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2026.In this work, we investigate airfoil tonal noise generation and reduction by the means of streak generators in form of cylindrical roughness elements. Roughness elements attenuate tones in the acoustic field for the case with chord base Reynolds number Re=80,000. Further, the coupling between structures generated by surface roughness and instability modes (Kelvin-Helmholtz) of shear layer has been identified through stability analysis, suggesting stabilisation mechanisms of Kelvin-Helmholtz instabilities by which the sound generation by the airfoil is reduced by the roughness elements.

© 2026 The Authors.Tip-Enhanced Raman Spectroscopy (TERS) provides nanoscale chemical sensitivity, but its routine use remains constrained by thermal drift, unstable optical coupling, heterogeneous hotspot formation, and inconsistent approaches to signal quantification. Here, we present a commissioning-oriented AFM-TERS workflow for planar Au thin films under the specific instrumental and substrate conditions used in this study. A 20 min thermal stabilization period reduced the lateral drift rate by approximately 3.6× (from 186 to 51 nm·min−1), thereby improving platform stability; however, the residual drift remains significant for long spectral maps and requires cautious interpretation of pixel-level co-localization. Optical coupling was standardized through a camera-based scattering-footprint analysis used as an operational alignment proxy, not as a direct measurement of the TERS hotspot or as a quantitative predictor of absolute Raman enhancement. Near-field mapping of Rhodamine 6G, Methylene Blue, and Crystal Violet confirmed local molecular identification at selected nanoscale positions, while paired far-field controls were used to evaluate the near-field contribution. Under the present experimental conditions, ensemble SERS on planar Au was practically limited to ≈10−6 mol·L−1, whereas TERS allowed local identification of R6G at selected positions on samples prepared down to 10−8 mol·L−1 via isolated, hotspot-mediated observations rather than as evidence of a practical detection capability. These measurements should not be interpreted as a formal statistical detection-limit study. Concentration-dependent measurements revealed strong local variability, including regimes in which substrate-mediated far-field hotspots locally dominated the response (FF > NF). We therefore recommend reporting paired near-field/far-field (NF/FF) intensity ratios and the differential signal metric (ΔI) as directly measurable descriptors that complement, rather than replace, conventional enhancement-factor estimates when the assumptions required for molecule-normalized EF calculations are uncertain.

© 2026 The AuthorsAdditively manufactured polylactic acid (PLA) is a lightweight, low-cost material for spacecraft hardware but undergoes rapid oxidative erosion in the atomic oxygen (AO) environment of low-Earth orbit (LEO). This study evaluates the AO resistance of PLA coated with Al₂O₃ films deposited by low-temperature thermal atomic layer deposition (ALD) using 100–1000 ALD cycles. Samples were exposed to low-pressure oxygen plasma in a capacitively coupled RF reactor under two exposure regimes: (i) a radical-dominated plasma bulk rich in atomic oxygen (O) radicals (with background O₂), and (ii) an ion-assisted cathode-sheath region where positive oxygen ions enhance material removal, used here as an accelerated oxidative-erosion proxy for AO-driven degradation. Atomic oxygen (O) generation in the plasma was monitored by optical emission actinometry, and FTIR, SEM, EDS mapping, spectroscopic ellipsometry on co-deposited Si reference coupons, and gravimetric analysis assessed chemical, morphological, and mass changes. In the plasma bulk, even the 100-cycle coating suppressed mass loss below the detection limit. In the cathode sheath, performance was orientation-dependent: in the face-up configuration (coated face toward the plasma), a 100-cycle coating reduced the etch rate by a factor of 82; in the face-down configuration, the reduction was by a factor of 3.90 relative to uncoated PLA, consistent with lateral ingress through edges and/or localized coating defects. Increasing the ALD cycle count improved face-down protection, and at 1000 cycles no measurable mass variation was detected for either orientation, indicating erosion suppression below the detection limit under cathode sheath exposure. Elemental mapping showed that incomplete coverage of recessed print features was a key cause of reduced protection at low cycle counts, which was mitigated by increased ALD cycle count and geometry-aware fixturing. Applying 250 ALD cycles to both sides of a flat PLA panel increases the mass by 37.5 mg per 100 cm2, while providing effective protection against both oxygen-radical ingress and ion-assisted erosion.

© Pleiades Publishing, Ltd. 2026.Abstract: This work presents an analysis of the thermal conversion of coal tar pitch (CTP), a toxic waste from the steel industry, into high-added-value products, such as syngas (H2 and CO) and nanostructured carbon black. A Double-Vortex Chamber Plasma Torch (DVCPT) was used to perform the gasification and pyrolysis of CTP. The electrical characteristics of DVCPT were experimentally investigated, operating at a power of 6–10 kW. Simultaneously, nanostructured carbon black (CB) with particle sizes of 70–100 nm and surface areas up to 130 m2/g was obtained. In addition, the composition of the gas was estimated theoretically, reaching up to 98% in syngas of the total volume of gas produced. These results highlight the advancement of industrial innovation, promoting a sustainable solution for the circular economy and mitigating environmental impacts associated with the management of carbonaceous industrial waste.

© 2026The influence of substrate surface roughness on the growth, adhesion, and tribological behavior of AlCoCrFeNiNb0.6 high-entropy alloy (HEA) coatings is reported in this manuscript. The coatings were deposited by magnetron sputtering onto API 5L X70 steel substrates using deposition powers of 100 W and 200 W. Two surface preparation conditions, mechanical polishing and abrasive blasting, were evaluated. Structural analysis by X-ray diffraction (XRD) indicated that the coatings were predominantly amorphous, while scanning electron microscopy (SEM) revealed that variations in morphology and thickness uniformity were dependent on both substrate topography and deposition power. Nanoindentation results showed hardness values of 9.9 GPa and 12.6 GPa, with corresponding elastic modulus of 189 GPa and 207 GPa, for coatings deposited at 100 W and 200 W, respectively. Adhesion tests demonstrated that increased substrate roughness significantly enhanced coating adhesion, with the critical load increasing from 316 mN to 4252 mN for the best-performing coating condition. For blasted substrates, the coefficient of friction was reduced from approximately 0.25 for the uncoated steel to values below 0.15 for the HEA-coated samples, with improved wear stability even under higher normal loads. Abrasive and fatigue wear mechanisms were predominant in the coated samples, whereas adhesive wear dominated the uncoated substrates. These results highlight that substrate surface condition is a key parameter for optimizing the adhesion and tribological performance of HEA coatings in mechanically demanding applications.

© 2026 by the authors.Turbines experience pressure losses from various sources, one of which is the tip leakage flow in the rotor blades. This is one of the main factors responsible for the decrease in turbine efficiency. This leakage is caused by pressure differences between the blade pressure and suction sides. High-pressure turbines with low aspect ratios and high-pressure loading face critical tip clearance losses, impacting turbine performance. One way to reduce tip leakage flow is to apply the desensitization technique to modify the rotor blade tip geometry. This study aims to apply the desensitization technique to the Energy-Efficient Engine developed by NASA. Different Winglet geometries with varying extensions along the blade tip chord (A— (Formula presented.), B— (Formula presented.), and C— (Formula presented.)), three types of Squealers with different rim dimensions and cavity heights (Squealer A and B), and the same rim thickness and cavity height of Squealer A with a decreased trailing edge region down to (Formula presented.) (Squealer C) were numerically tested. Additionally, the study simulates blending Winglet A with Squealer A (Squealer–Winglet A), Squealer A with Winglet B (Squealer–Winglet B), and Winglet A with Squealer B (Squealer–Winglet C). Numerical simulations are conducted and compared with experimental data. Comparing the various geometries at the design-point pressure ratio, the Winglet A configuration demonstrates an increase of (Formula presented.) in efficiency, Squealer C an increase of (Formula presented.), and for cases involving all Squealer–Winglet models, no improvement was obtained. For (Formula presented.) N at the design-point pressure ratio, Winglet B demonstrates an increase of (Formula presented.) in efficiency, Squealer C an increase of (Formula presented.), and Squealer–Winglet A an increase of (Formula presented.). These are interesting results in the case of the engine operating at cruise condition, in which the rotational speed is around (Formula presented.) N.

© 1965-2011 IEEE.Aviation plays a fundamental and valuable role in the modern world, yet it faces significant challenges, including high fuel costs and substantial environmental pollution. These issues have prompted the aviation industry to establish emission standards and develop less-polluting propulsion systems, such as those utilizing synthetic fuels, fuel cells, and electrification. Among these, electrification holds promise as a potential solution for reducing emissions in commuter aircraft, despite the mass limitations posed by batteries. In this study, a methodology was developed and implemented within in-house software to simulate the performance of a commuter aircraft with a hybrid-electric propulsion system. The analysis focused on key metrics like fuel economy and climb time to cruise altitude. The EMB-120 Brasilia was chosen as the base aircraft for this research. Its long-standing use by the Brazilian Air Force (FAB), the authors' extensive familiarity with its performance, and the availability of experimental data for lift and drag coefficients made it an ideal model for our simulations. To evaluate the performance of the hybrid propulsion system and compare it with the standard case, a gas turbine was utilized as the primary engine. Mathematical models were developed for the PW118 gas turbine, which powers the real aircraft that was considered the standard case, and for the PT6A-68C, which was suggested as a substitute for the hybrid system. To evaluate the aircraft's performance, a standard mission was simulated on a short-range route of 926 km (500 NM), flying at an altitude of 7,620 m (25,000 ft), a common mission that is used by Brazilian Air Force. For hybrid simulations, battery packs were tested with specific energies ranging from 0.125 kWh/kg to 0.750 kWh/kg, in multiples of the initial value. Batteries with 0.250 kWh/kg were considered the current state-of-the-art, while the 0.750 kWh/kg packs represent an extreme upper bound associated with far-future technological developments. The results demonstrated significant performance gains depending on the chosen battery technology and the power split, the hybrid system achieved fuel savings of up to 18% to 19% and reduced climb time by 17% to 25%.

© 2026 The Author(s).Sustainable aviation fuels (SAFs) are a critical pathway for reducing carbon dioxide (CO2) emissions from the aviation sector, yet the deployment of new SAF candidates requires a robust understanding of their fundamental combustion behavior. Limonene, a renewable terpene derived from pine and citrus biomass, has emerged as a promising candidate due to its favorable energy content and bulk properties relative to conventional Jet A-1. However, despite increasing interest, fundamental premixed combustion data for limonene—particularly laminar burning velocity and flame stability parameters—remain limited. The aim of this study is to address this gap through an experimental investigation of the premixed combustion characteristics of limonene. Laminar burning velocity measurements were performed in spherical and cylindrical constant-volume reactors at atmospheric pressure and unburned-gas temperatures of 358, 398, and 438 K using Schlieren imaging. Experiments were conducted for pure limonene, the Jet A-1 surrogate fuel MURI-1, and a 70/30 (vol./vol.) MURI-1–limonene blend over equivalence ratios from 0.7 to 1.4. The results show that pure limonene exhibits high laminar burning velocities, reaching peak values of approximately 70 cm s⁻1, exceeding those of conventional kerosene surrogates. Flame stability analysis reveals that limonene flames become increasingly sensitive to stretch under fuel-rich conditions, as indicated by decreasing Markstein length and Lewis number. Blending limonene with MURI-1 yields intermediate burning velocities and improves flame stability through increased Markstein length, despite a modest reduction in flame thickness, with enhancements of up to 8% observed under rich conditions. These findings provide new fundamental combustion data for limonene and demonstrate combustion trends consistent with other SAF candidates, supporting its potential as a viable component for future ASTM-certified sustainable aviation fuel formulations and for the development of validated chemical-kinetic models.

© 2026 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license. http://creativecommons.org/licenses/by/4.0/This paper investigates how a single vibration neutraliser can be attached to a beam to create a wide frequency range in which vibration transmission is reduced. This range, termed the smooth wide attenuation band (WAB), is defined as the region where the displacement transmissibility across the beam is below unity and exhibits no peaks or troughs. The concept is motivated by similar behaviour observed in mono-coupled periodic rods. The primary aim of the study is to identify the physical mechanisms responsible for the formation of the WAB and to establish an effective approach for tuning the neutraliser. Using the receptance method, with the beam modelled using its vibration modes, it is shown that the formation of a WAB requires specific conditions. The neutraliser must be placed at a nodal point of the beam and be tuned such that the real part of its dynamic stiffness is equal and opposite to the mass-like receptance of the beam at the corresponding natural frequency. The analysis shows that the WAB results from a degenerate mode condition in which two vibration modes of the combined beam–neutraliser system coincide in frequency. Numerical simulations indicate that attaching the neutraliser at the nodal point nearest to the end of the beam which is excited, produces a wider WAB and greater reduction in transmissibility than using the nodal point near the opposite end. These findings, which are supported by experimental validation, provide new physical insight into the WAB phenomenon on a beam.

© 2025 Elsevier Ltd.The dynamics of hanging chains, a topic studied since the 18th century, has relevance in contemporary engineering applications, particularly in low-frequency vibration control. This paper concerns the use of hanging chains to mitigate vibrations of a host structure. To enable predictions to be made and to identify the key parameters of the chain, four models are developed, each of which contributes to the predictions and physical insight in a different way. The first is a continuous model, which is only strictly valid at relatively low frequencies, when the length of a chain link is small compared to the wavelength at the top of the chain. The second is a finite element model considering a chain made of discrete rigid links, which is valid up to much higher frequencies. The other two models are an approximate hybrid lumped parameter/continuous model, which provides some additional physical insight, and a very simple approximate lumped parameter model, which can be used to predict the vibration attenuation effectiveness of a chain when connected to a host structure. Laboratory measurements are presented to assess the validity of the models and to demonstrate the efficacy of chains as a passive vibration control device.

© 2025 Wiley-VCH GmbH.Graphene oxide (GO) has attracted huge interest due its exceptional properties, being widely applied in many applications such as: flexible sensors, biomaterials, coatings, and energy storage. However, the direct application of these materials in their pure form is challenging due to their tendency to agglomerate and hard processability. To overcome these limitations, GO is often combined with other materials, giving rise to composites, hybrid mixtures, conductive inks, and structured films, expanding their application possibilities in different technologies. Thus, properties such as piezoresistivity can be explored allowing their use in the development of deformation and impact sensors, structural monitoring devices, and intelligent detection systems. In this study, the piezoresistivity of GO ink on different surfaces is investigated, analyzing how the combination of GO with ethylcellulose and terpineol influences its electrical and mechanical properties. A complete characterization is carried out to understand the polymeric interactions of the ink. A gauge factor of up to 30, in polyetherimide substract, is observed with a strain of 2% and low hysteresis.

© The Author(s) 2026.The application of uncertainty quantification (UQ) methods to realistic industrial-scale structures remains a challenging task, due to the typical geometric complexity, the existence of various sources of uncertainties and the high dimension of structural models. These challenges are even bigger when dealing with composite material structures, which are knowingly prone to uncertainties arising from manufacturing processes and environmental influences. In this context, the present paper intends to contribute to increase the maturity level of UQ techniques to composite aeronautic structures, under the combined effects of space-dependent material and environmental fluctuations. Variations in temperature, laminate thickness and fiber volume fraction are jointly considered, being represented as random fields discretized using the Karhunen-Loève Expansion (KLE), while fiber angles are treated as random variables. Aiming at expanding the range of situations possibly found in practice, both Gaussian and non-Gaussian random fields are considered within a methodology combining the Iterative Translation Approximation Method (ITAM) and KLE. A micromechanical model is used to represent temperature- and moisture-dependent material properties, capturing the coupled effects of environmental degradation of material properties and hygrothermally-induced stresses. Monte Carlo Simulation (MCS) is employed to perform uncertainty quantification for buckling loads and vibration natural frequencies of a regional aircraft composite wing structure modeled with a relatively high-dimension finite element model. Additionally, global sensitivity analysis based on Sobol’ indices is conducted to identify the most influential random parameters, where structural responses are approximated using artificial neural network (ANN)-based surrogate models. From the simulation scenarios analyzed, accounting for different values of standard deviations attributed to random variables and correlation lengths assigned to random fields, the statistics of structural responses are assessed. The significant spread of structural responses highlights the importance of incorporating the considered types of uncertainty in analysis and design procedures for achieving robust and reliable aerospace composite structures.

© 2025 Wiley-VCH GmbH.Graphene oxide (GO) has attracted huge interest due its exceptional properties, being widely applied in many applications such as: flexible sensors, biomaterials, coatings, and energy storage. However, the direct application of these materials in their pure form is challenging due to their tendency to agglomerate and hard processability. To overcome these limitations, GO is often combined with other materials, giving rise to composites, hybrid mixtures, conductive inks, and structured films, expanding their application possibilities in different technologies. Thus, properties such as piezoresistivity can be explored allowing their use in the development of deformation and impact sensors, structural monitoring devices, and intelligent detection systems. In this study, the piezoresistivity of GO ink on different surfaces is investigated, analyzing how the combination of GO with ethylcellulose and terpineol influences its electrical and mechanical properties. A complete characterization is carried out to understand the polymeric interactions of the ink. A gauge factor of up to 30, in polyetherimide substract, is observed with a strain of 2% and low hysteresis.

Copyright © 2026. Published by Elsevier Ltd.Slurry transport in tumbling mills is rarely resolved at the particle scale, limiting the prediction of discharge performance in large ball mills. In particular, the application of grate discharge in mills of 20–28 ft diameter has been constrained by uncertainty in evacuation capacity and the risk of restriction under high-throughput conditions. This work presents a particle-resolved Smoothed Particle Hydrodynamics–Discrete Element Method (SPH–DEM) framework to investigate slurry–particle interactions at the discharge interface. The granular phase is resolved by DEM within a GPU-based Blaze framework, and the slurry phase is advanced by a natively integrated SPH module built on the DualSPHysics formulation. Within this implementation, particles relevant to charge dynamics and discharge interactions are explicitly resolved by DEM, while the sub-resolution fine and ultra-fine fraction is represented by the slurry-phase properties (density, viscosity, solids fraction). This combination enables direct simulation of industrial-scale ball mills, capturing free-surface and multiphase dynamics at the discharge interface without relying on homogenization assumptions (e.g., porous-medium or averaged-mixture representations) for the resolved particulate bed. The results show that discharge is not governed by geometric open area alone, but by a dynamically evolving effective discharge area reduced by transient particle–slot interactions. These finite-duration restriction events are continuously formed and resolved, producing a statistically stable deficit in discharge capacity at the mill scale. This behavior is captured through a dimensionless Withdrawal Restriction Number, which combines particle size, slot geometry, and expansion effects. The effective discharge area follows a bounded relation as a function of this parameter, defining transitions between self-cleaning and restriction-dominated regimes. At the system level, grate discharge suppresses slurry pooling, reduces total power draw in the industrial comparison reported here, and shifts energy utilization toward impact-dominated events, enabling operation at lower grinding media load without measurable product coarsening in the analyzed plant case.

© 2025 Elsevier Masson SAS.This study investigates the use of an artificial neural network-based method for solving one-dimensional inverse heat conduction problems, providing insights into the behavior of network weights and their performance in estimating heat flux in near real-time, in comparison with classical methods such as the sequential function specification method (SFSM) and Tikhonov regularization based filter solutions. This class of problems involves estimating the unknown boundary heat flux condition from experimental temperature measurements at accessible locations. While neural networks have become increasingly popular in this area, there is limited understanding of how their internal parameters, particularly the weights, behave. This article explores the structure of these neural network weights, showing that they exhibit a well-defined, linear, and approximately antisymmetric pattern for this type of problem. With the aid of the neural network solution, it is possible to identify a model for the filter coefficients, referred to in this study as Linear Structured Filter Coefficients (LSFC). The method was applied to real temperature data obtained from laboratory experiments on an AISI 1040 steel plate, in which the heat flux supplied by a resistive heater was estimated using the LSFC approach. The results were compared with traditional filter-based methods, such as Tikhonov regularization and the Sequential Function Specification Method (SFSM). In this study, the LSFCs provide a more compact solution, requiring fewer temperature data points and resulting in shorter response delays, making them suitable for near real-time heat flux estimation.

© The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2026.This article proposes a modification to the Transient Plane Source (TPS) method for simultaneous estimation of thermophysical properties in low thermal conductivity and moderate-to-high volumetric heat capacity materials like powders, by solving the inverse parameter estimation problem employing Levenberg–Marquardt (LM) algorithm using an integrated COMSOL and MATLAB LiveLink approach. The symmetric placement of thermocouples on either side of the Kapton-insulated TPS sensor further enhances sensitivity and reduces parameter correlation. Sensitivity and correlation analysis was conducted to identify a suitable location for the additional thermocouples, aimed at improving the accuracy of the estimation. The forward model was developed in COMSOL and was connected to the inverse problem solving LM algorithm in MATLAB using LiveLink server. Using the combined dataset consisting of experimental TPS data (obtained from Zhang et al. in Prog Comput Fluid Dyn 13:191–201, 2013) and numerically generated thermocouple data, the proposed inverse framework yielded mean deviations in thermal conductivity and specific heat capacity of less than 1 % for both materials. The deviation in the estimated thermal conductivity reported by Zhang et al. (Prog Comput Fluid Dyn 13:191–201, 2013) was 1.92 % for stainless steel and 2.86 % for ceramic.

© 2026 The Authors.Laser welding of 5083-H112 aluminum alloy presents several challenges due to the material's high reflectivity and thermal conductivity. Consequently, it becomes difficult to establish a processing window that properly associates parameters with the desired weld bead geometry. This study aims to analyze and compare the predictive performance of five widely used machine learning regression techniques (Support Vector Regression, Decision Trees, Random Forest, K-Nearest Neighbors, and Artificial Neural Networks) for estimating weald bead geometry, considering a challenging dataset. It has small size, high process variance, and a discontinuity corresponding to the conduction-to-keyhole transition, thereby providing an important benchmark for assessing the models' capability of calibration on limited datasets. Weld bead width and penetration depth were selected as outputs, while scanning speed and power as inputs. A total of 99 bead-on-plate experiments were performed by combining 11 levels of laser power (1000 to 4600 W) and three levels of scanning speed (0.5, 1.0, and 4.0 m/min), within each parameter combination, process repeatability was accessed. The dataset was split into training (80%) and testing (20%) subsets. The best hyperparameters for each machine learning technique were determined by using GridSearch and five-fold cross-validation. The K-Nearest Neighbors technique resulted as the most recommended due to its low mean absolute percentage error, 4.68% for width and 8.35% for penetration depth, combined with the generation of smoother curves for physical plausibility. Feature importance analysis highlighted laser power as predominant factor. The proposed techniques demonstrate strong potential for industrial implementation, specially assisting technical personnel in defining process windows.

© 2026, Begell House Inc. All rights reserved.Parallelized computation with Graphics Processing Unit (GPU) offers significant advantages for Computational Fluid Dynamics (CFD) problems, leveraging their massively parallel architecture to efficiently solve large-scale, computationally intensive tasks such as fluid flow simulations. This study presents a novel GPU Fully-Implicit Finite Volume Solver (GPU-FIFVS) designed to solve the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations of k-ω Shear Stress Transport (SST) turbulence model. To demonstrate the speed gained by using GPU vs CPU based finite volume computations and considering turbulent flow conditions, this research focused on two well-known cases: NACA (National Advisory Committee for Aeronautics) 0012 airfoil and Backward Facing Step (BFS). Simulations were carried out using two computational frameworks: a GPU-based solver implemented via Nvidia Compute Unified Device Architecture (CUDA) architecture, and a commercial software relying on conventional Central Processing Unit (CPU)-based processing. The study evaluates flow characteristics through wall shear stress and pressure distributions, along with velocity profiles. Simulated results are compared to well-known experimental data to assess predictive consistency across platforms. GPU-based simulations were conducted on a high-end consumer-grade GPU with 32 GB of memory, while CPU-based runs utilized a multi-core CPU operating at up to 4.3 GHz. The findings highlight that the GPU implementation delivers an improved computational time compared to the CPU-based solution, demonstrating the improvement with the application of GPU-FIFVS approach.

© The Author(s), 2026. Published by Cambridge University Press.Collaborative robots (cobots) have emerged as a pivotal paradigm for the upcoming leap to Industry 5.0. In recent years, the range of applications has expanded significantly, particularly in assembly tasks within the manufacturing industry. The primary goal of this paper is to review the application of cobots in industrial assembly tasks, highlighting possibilities for innovative research in smart robotics, including prospects for challenging applications in aircraft final assembly processes. The paper systematically reviews recent literature to analyse the use of collaborative robotics in industrial assembly tasks, encompassing characterisation of application environments, motivations, characteristics and outcomes of relevant use cases across various industrial segments. Additionally, it reviews a set of innovative technological patents issued by the aeronautical industry over the past 14 years, highlighting trending projects in industry. The investigation reveals that the automotive and electronics industries remain at the forefront of cobot applications, mainly for tasks like pick-and-place operations and component manipulation. Applications in open work cells, where humans and robots operate at supportive or sequential interaction levels, using conventional communication interfaces and camera-assisted technologies, have been the most prevalent. The review identifies potential opportunities and key aspects from future application scenarios for cobots. The findings are relevant to the industrial robotics community, emphasising the need for novel applied research on human–robot colla boration in aeronautical industry.

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.With the advancement of techniques for designing manned and unmanned aircraft, testing systems and dynamics in a previous phase became necessary. These tests are done through simulations with movement on or without a Stewart platform. The tests aim to determine the in-flight behavior of the systems and dynamics of the designed aircraft. Aiming at this type of test, this research aims to design a flight simulator with a flight envelope safe enough for actuator testing. The data used for the aircraft dynamics are from the F-16 Block 50. The tested actuator models are from the A7-D, DC-8, and F-16 aircraft. For the development of the flight envelope, a Stability Augmentation System (SAS) was designed using root locus, seeking optimization in various sets of speed and altitude. This scaled gain technique makes the aircraft controllable by one pilot throughout the defined flight envelope. Ultimately, a stable and reliable simulation environment was obtained for testing different actuators. The next step in this research is embedding the software on the robotic simulation platform SIVOR for pilot tests.

© The Author(s) 2026.Traditional aircraft rely on a combination of ailerons, elevators, rudders, and propulsion for flight control. However, a failure in the rudder can significantly compromise lateral-directional control and even be catastrophic, depending on flight phase and the aircraft dynamics. Recent advancements in hybrid-electric propulsion technologies offer new opportunities for using differential thrust to enhance aircraft safety. This paper presents four novel contributions to hybrid-electric aircraft control: (1) a modified Daisy Chaining control allocation that eliminates fault detection modules by using actuator position feedback for seamless transition; (2) a systematic MIMO PID controller design methodology specifically optimized for hybrid-electric differential thrust with Target-Zeros tuning that allows the reuse of the same controller for rudder actuation (reducing complexity by having less components and using less memory for the gains); (3) comprehensive analysis of electric motor dynamics requirements for aircraft with different Dutch-Roll characteristics; and (4) design guidance and insights for implementation of the proposed solution in a practical application, to address the real-world challenges mapped in this work. We applied this control law to two aircraft models: a wide-body jet airliner and a multi-role fighter, both equipped with hybrid-electric propulsion systems. The control system was optimized using advanced tuning techniques and incorporated an over-actuation strategy through a Daisy Chaining architecture. Our results demonstrate that the proposed control strategy achieves yaw control performance comparable to traditional systems while effectively mitigating the impacts of rudder failures, which means it is suitable as a safety mechanism able to stabilize the aircraft during an emergency until safe landing, that would otherwise be catastrophic without this system. However, the scalability of this approach is limited, as maintaining performance at higher yaw angles requires increased propulsion sizing. These findings highlight the need for further research to assess the feasibility of using differential thrust as a primary control mechanism—and not just a fallback control strategy—in aircraft equipped with hybrid-electric and distributed electric propulsion.

© 2026, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.The turn-back maneuver—colloquially known as the “impossible turn”—following engine failure after takeoff remains a contentious subject in aviation safety. Often discouraged in civil operations yet critical for military contingency planning, this maneuver requires a precise understanding of aerodynamic limits. This study evaluates the stall speed dynamics during the turn-back using the EMBRAER-312 Tucano aircraft (designated T-27 in the Força Aérea Brasileira), contrasting Aircraft Flight Manual (AFM) steady-state data with flight test results obtained from high-fidelity instrumentation. The investigation highlights significant discrepancies in which AFM-derived stall speeds prove excessively conservative for the dynamic conditions of the return profile. The results confirm that stall margins are more accurately predicted using an instantaneous load factor (nza ) model, which accounts for vertical trajectory unloading. These findings challenge the reliance on static performance charts for dynamic emergency scenarios and demonstrate that, with proper technique—specifically the pitch-up entry followed by a timely nose-down transition—the maneuver can be executed at bank angles of up to 60◦ with safer margins than traditionally assumed, resolving the conflict between geometric necessity and aerodynamic safety.

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.The joint 8th Drag Prediction Workshop (DPW-8) and 4th Aeroelastic Prediction Workshop (AEPW-4) evaluate computational aeroelastic analysis and drag predictions for aircraft. The initiative promotes collaboration between aerodynamics and aeroelasticity communities, focusing on enhancing simulation methodologies based on the Common Research Model (CRM), a benchmark aircraft supported by extensive experimental and finite element data. The ITA-Embraer team is developing a fluid-structure interaction (FSI) framework using SU2 as the computational fluid dynamics (CFD) solver and MSC Nastran for the finite element method (FEM) solver. A major challenge in this process is the high computational cost due to the fine structural mesh provided by NASA, which increases simulation time during iterative FSI coupling cycles. To address this, a coarser FEM mesh was proposed and validated through detailed comparisons with the original high-fidelity model. Results demonstrated strong agreement in natural frequencies and mode shapes, confirming that the reduced mesh preserves essential structural dynamics and statics characteristics. Additionally, the FEA runtime was reduced by approximately 60%, significantly improving computational efficiency without compromising result quality.

© Pleiades Publishing, Ltd. 2026.Abstract: This work presents an analysis of the thermal conversion of coal tar pitch (CTP), a toxic waste from the steel industry, into high-added-value products, such as syngas (H2 and CO) and nanostructured carbon black. A Double-Vortex Chamber Plasma Torch (DVCPT) was used to perform the gasification and pyrolysis of CTP. The electrical characteristics of DVCPT were experimentally investigated, operating at a power of 6–10 kW. Simultaneously, nanostructured carbon black (CB) with particle sizes of 70–100 nm and surface areas up to 130 m2/g was obtained. In addition, the composition of the gas was estimated theoretically, reaching up to 98% in syngas of the total volume of gas produced. These results highlight the advancement of industrial innovation, promoting a sustainable solution for the circular economy and mitigating environmental impacts associated with the management of carbonaceous industrial waste.

© The Author(s) 2026Calcium silicate cements (CaSiO3) are widely used in bone repair treatments for both medical and dental applications. To meet the demands of tissue engineering, three calcium silicate cements were developed: a control group without carbon nanotubes (CNT) and two experimental groups incorporating CNT nanoparticles at concentrations of 0.2% and 0.5%. The surface topography of the calcium silicate-based cements was analyzed using field emission scanning electron microscopy (FEG-SEM) and X-ray diffraction. Additionally, an in vitro cell viability assay was performed to assess cytotoxicity. An in vivo study was also conducted using 24 Wistar rats, where critical bone defects of 3.0 mm in diameter were surgically created in both tibiae using a trephine drill. A clot group was included as a control. Following euthanasia, the samples were evaluated through histological and histomorphometric analyses, and a three-point flexural biomechanical test was performed. Statistical analysis was conducted using one- and two-way ANOVA, with a significance level set at 5%. The results indicated that none of the cements exhibited cytotoxicity. Regarding bone neoformation, the clot group showed significantly lower values compared to the SiCa and SiCa+0.5%CNT (mass) groups (p < 0.05), while the SiCa+0.2%CNT group did not differ statistically from the others (p > 0.05). The biomechanical test revealed a statistically significant difference between the SiCa+0.2%CNT group and the SiCa and SiCa+0.5%CNT groups, with the SiCa+0.2%CNT group exhibiting lower values (p < 0.05), whereas the clot group showed no statistical difference from the other groups (p > 0.05). These findings indicate that the incorporation of carbon nanotubes (CNT) into calcium silicate cements did not result in significant differences in bone tissue regeneration when compared to cements without CNT.

© 2026 by the authors.Electrospinning (ES) can produce nonwoven fibrous mats with high surface area and interconnected porosity, making them attractive for biomedical and functional material applications. However, conventional ES often relies on volatile organic solvents, raising safety, environmental, and translational concerns. Fully aqueous (“green”) ES offers an appealing alternative, although many water-soluble polymers remain difficult to spin and may show limited stability under hydrated conditions. In this study, two fully aqueous binary systems, poly(vinylpyrrolidone)–sodium alginate (PVP–SA) and poly(vinylpyrrolidone)–riboflavin (PVP–RF), were investigated to decouple the roles of sodium alginate (SA) and riboflavin (RF) on solution behaviour, fibre formation, morphology, dry-state mechanical properties, and surface chemistry. Aqueous PVP solutions (20% w/v; molecular weight 1.3 MDa) were blended with SA (1–5 wt% relative to PVP) or RF (1–10 wt% relative to PVP). Electrical conductivity and rheological properties were evaluated prior to ES under controlled conditions, with simultaneous ultraviolet (UV) exposure at 344 nm during fibre collection. RF did not significantly alter conductivity (~0.74–0.75 µS·cm−1), whereas SA increased conductivity up to 2.75 ± 0.03 µS·cm−1 at 5 wt%. All formulations exhibited shear-thinning behaviour, while 10 wt% RF increased the zero-shear viscosity relative to neat PVP. Morphological analysis showed that low SA contents produced uniform fibres, whereas higher SA levels (4–5 wt%) led to bead defects and reduced fibre diameter (down to 85 ± 25 nm). Dry-state mechanical performance decreased with increasing SA content, while 10 wt% RF improved tensile strength and toughness, reaching an ultimate tensile strength of 5.21 ± 0.15 MPa and toughness of 40.51 ± 1.53 MJ·m−3. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) indicated subtle UV-driven redistribution of surface chemical states, consistent with mild photo-oxidative microstructural modification rather than extensive covalent network formation. Because the UV irradiance was not directly measured and wet-state stability was not assessed, the UV-related findings are interpreted as preliminary chemical evidence rather than confirmation of stabilized fibre mats. Overall, this work establishes a solvent-free aqueous ES platform in which ionic and photoactive additives can be used to tailor fibre morphology, dry-state mechanical behaviour, and surface characteristics without toxic reagents.

© 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.High-temperature oxidation is a major challenge in steel thermomechanical processing, as oxide scale formation reduces performance, increases production costs, and accelerates material degradation. The rate of oxidation is strongly influenced by temperature, and alloy composition, with temperature-dependent behaviors often governed by the formation and stability of protective oxide layers. Classical oxidation models, such as parabolic and linear rate laws, are limited because they assume planar geometries and single-limiting step mechanisms, making them unsuitable for multi-step oxidation or for comparing alloys with distinct oxide compositions. In this study, the Unreacted Shrinking Core Model (USCM) was, for the first time, applied to describe the oxidation rate of four distinct steel alloys (AISI 1045, 1095, 4340, and D6) oxidized between 900 °C and 1200 °C. The model was fitted to experimental data, supported by SEM, EBSD, and XRD characterization. Results show that scale diffusion and mixed diffusion–reaction mechanisms govern oxidation in AISI 1045, 1095, and 4340, while AISI D6 oxidation is primarily surface-reaction controlled due to its high chromium content. Among the alloys, AISI D6 exhibited the highest oxidation resistance, following a reaction-controlled oxidation rate mechanism, while AISI 1095 also showed improved resistance at 900–1000 °C attributed to its high carbon content. The USCM successfully quantified metal-to-oxide conversion as a function of temperature and time, enabling the determination of Arrhenius parameters for reaction rate and diffusivity, which can be extrapolated to different geometries. This geometry-flexible framework makes the USCM highly relevant for optimizing processing parameters such as working temperature, time and alloy composition in industrial applications.

© 2026 by the authors.Acrylic resin is widely used in the fabrication of complete dentures, interacting significantly with the intraoral environment. However, complete dentures face challenges such as stability issues and biofilm accumulation. Glaze application is a common method to reduce surface porosity and microbial adhesion, but it also decreases surface wettability, potentially impairing salivary film formation essential for peripheral sealing. This study aimed to incorporate titanium dioxide and zinc oxide nanoparticles into the glaze applied to thermally activated acrylic resin (TAAR) via spray coating to enhance surface wettability and antifungal activity. Four groups were tested: G (TAAR + commercial glaze − control); AlG (TAAR + commercial glaze + aluminum oxide − roughness control); TiG (TAAR + commercial glaze + titanium dioxide); and ZnG (TAAR + commercial glaze + zinc oxide). Evaluations included flexural strength, color and translucency, surface analysis and antibiofilm activity against Candida albicans. Data were analyzed using one-way ANOVA. No statistically significant differences in mechanical strength (MPa) were observed (G: 108.54 ± 8.36; AlG: 113.60 ± 11.95; ZnG: 111.98 ± 9.27; TiG: 113.66 ± 10.41). Surface roughness significantly increased, and contact angle decreased, indicating improved wettability. Regardless of the antifungal activity no improvement was detected (G: 6.71 ± 0.10; AlG: 6.82 ± 0.08; ZnG: 6.72 ± 0.20; TiG: 6.66 ± 0.18). In conclusion, the incorporation of nanoparticles into the glaze improves the wettability of acrylic resin surfaces, potentially enhancing peripheral sealing and denture retention, which is beneficial for patients with reduced alveolar ridge height.

© 2025 Wiley-VCH GmbH.Graphene oxide (GO) has attracted huge interest due its exceptional properties, being widely applied in many applications such as: flexible sensors, biomaterials, coatings, and energy storage. However, the direct application of these materials in their pure form is challenging due to their tendency to agglomerate and hard processability. To overcome these limitations, GO is often combined with other materials, giving rise to composites, hybrid mixtures, conductive inks, and structured films, expanding their application possibilities in different technologies. Thus, properties such as piezoresistivity can be explored allowing their use in the development of deformation and impact sensors, structural monitoring devices, and intelligent detection systems. In this study, the piezoresistivity of GO ink on different surfaces is investigated, analyzing how the combination of GO with ethylcellulose and terpineol influences its electrical and mechanical properties. A complete characterization is carried out to understand the polymeric interactions of the ink. A gauge factor of up to 30, in polyetherimide substract, is observed with a strain of 2% and low hysteresis.

© 2025 Elsevier B.V.Bioactive glasses are recognized for their ability to release ions and induce apatite formation in physiological media. However, conventional glasses often cause a marked increase in pH during dissolution, which may lead to cytotoxic effects. In this study, chlorinated bioactive glasses were synthesized via a hydrolytic sol–gel route using tetraethyl orthosilicate (TEOS) and calcium chloride, aiming to obtain materials with efficient ionic release and controlled pH response. Samples were thermally treated at 500 °C, 600 °C, and 700 °C and characterized by FTIR, Raman spectroscopy, specific surface area (BET), scanning electron microscopy (SEM), and ionic release tests. The chlorinated bioactive glass calcined at 500 °C exhibited the most promising combination of characteristics: presence of hydroxyl groups (–OH), a structure predominantly composed of Q² units, high specific surface area (31.75 m² g⁻¹), well-defined mesoporosity, high ionic release (∼2000 µS cm⁻¹), and effective control of pH increase in aqueous media. These properties directly contribute to bioactivity and indicate that this material can be incorporated into biomedical formulations without the need for prior neutralization steps, in contrast to many conventional bioactive glasses. The results also demonstrate that the hydrolytic sol–gel route enables the synthesis of chlorinated bioactive glasses with tunable structure and dissolution profiles, overcoming limitations associated with more complex routes, such as those based on ion-exchange resins or precursors like metasilicate. The ability to combine high ionic release with low impact on pH represents a relevant advance in the design of bioceramics for regenerative and dental applications.

© 2025 The Author(s). Journal of the American Ceramic Society published by Wiley Periodicals LLC on behalf of The American Ceramic Society.Graded multilayer zirconias exhibit a microstructural gradient based on yttria content, but the transition zone between layers remains poorly characterized. This study evaluated the fracture energy required to create new surfaces in multilayer zirconias. Brazil-nut specimens were tested under different loading angles to induce tensile, shear, or mixed failure modes, using 3Y-TZP and 5Y-PSZ as controls. Groups were defined by zirconia type, loading angle, and hydrothermal aging. Fractured specimens underwent fractographic analysis, failure classification, scanning electron microscopy, and energy-dispersive X-ray spectroscopy characterization. Two-way analysis of variance revealed significant differences between loading angles but not aging. At 25°, where shear forces predominated, fracture energy was significantly higher [baseline: 964.74 (± 202.43); aged: 1389.12 (± 978.47) N/m] compared with most groups, except 15°. Multilayer zirconia showed intermediate fracture energy values between 5Y-PSZ and 3Y-TZP. Importantly, the transition zone presented a heterogeneous interphase rather than a smoothly graded structure. Shear stresses required higher energy release than tensile stresses. These results reveal the microstructural discontinuity and distinct fracture behavior of multilayer zirconias, providing new insights into the structure–property relationships of this class of ceramics.

© 2026 The Author(s).The demand for ultrafast transportation and strategic defense systems has intensified research on air-breathing hypersonic vehicles powered by scramjet engines. These systems face critical technological challenges, particularly the strong coupling between propulsion and flight dynamics. Current simulation frameworks often oversimplify engine behavior, neglecting effects such as heat transfer, supersonic combustion, and compressible flow. To address this gap, this work develops an integrated simulation model that couples six-degree-of-freedom rigid-body flight dynamics with a thermodynamic model of a scramjet engine. The framework incorporates atmospheric and mass variation models, aerodynamic coefficients based on engineering methods, and full-actuator dynamics. Control laws are implemented through inner-loop stabilization and outer-loop autopilot logic. Simulation results indicate that the vehicle maintains aerodynamic stability from Mach 5 to 10, with maximum efficiency near Mach 8. Lift, drag, and pitching moment coefficients show consistent compressibility effects, while elevon deflections provide effective control authority across the hypersonic envelope. Dynamic mode analysis reveals lightly damped open-loop behavior typical of hypersonic configurations, especially in roll and pitch, which are stabilized by control laws.

© The Author(s) 2026.The dynamics of hypersonic flight present significant challenges due to extreme thermal conditions and the strong coupling between the airframe and propulsion system, making vehicle design highly complex. Scramjet engines, while structurally simple, require extensive optimization, particularly in material selection and thermodynamic efficiency. To address these challenges, this study developed and integrated a complete six-degree-of-freedom (6DoF) dynamic model with a detailed thermodynamic representation of a scramjet-powered LOGAN hypersonic vehicle. This coupled framework enables a holistic assessment of the interactions between flight dynamics and engine thermodynamics, capturing the mutual influence of propulsion variations on vehicle trajectory and vice versa. The model was validated through simulations of a high-speed cruise scenario, where the vehicle transitioned from 65,000 to 100,000 ft at Mach 10, demonstrating stable altitude capture and performance consistency. The results revealed that scramjet operation at higher Mach numbers enhances thermal and exergy efficiencies, exceeding 70% at Mach 10, although these values do not include propulsive efficiency effects. However, the improved thermodynamic performance at higher Mach regimes is accompanied by significantly higher fuel demand, with fuel mass flow rates stabilizing above 6.5 kg/s at Mach 10 compared with values below 3 kg/s at Mach 5, while intermediate regimes between Mach 7 and Mach 8 presented a more balanced operational condition between efficiency and fuel consumption. The propulsion model effectively regulated thrust-to-drag balance, ensuring an efficient transition between flight phases. The combustion process was identified as the primary source of exergy loss, with heat addition generating peaks exceeding 3 × 106 W, reinforcing the need for advanced fuel injection and thermal management strategies. The integrated approach developed in this study provides a valuable framework for assessing next-generation conceptual hypersonic vehicles studies.

© 2026, Begell House Inc. All rights reserved.Parallelized computation with Graphics Processing Unit (GPU) offers significant advantages for Computational Fluid Dynamics (CFD) problems, leveraging their massively parallel architecture to efficiently solve large-scale, computationally intensive tasks such as fluid flow simulations. This study presents a novel GPU Fully-Implicit Finite Volume Solver (GPU-FIFVS) designed to solve the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations of k-ω Shear Stress Transport (SST) turbulence model. To demonstrate the speed gained by using GPU vs CPU based finite volume computations and considering turbulent flow conditions, this research focused on two well-known cases: NACA (National Advisory Committee for Aeronautics) 0012 airfoil and Backward Facing Step (BFS). Simulations were carried out using two computational frameworks: a GPU-based solver implemented via Nvidia Compute Unified Device Architecture (CUDA) architecture, and a commercial software relying on conventional Central Processing Unit (CPU)-based processing. The study evaluates flow characteristics through wall shear stress and pressure distributions, along with velocity profiles. Simulated results are compared to well-known experimental data to assess predictive consistency across platforms. GPU-based simulations were conducted on a high-end consumer-grade GPU with 32 GB of memory, while CPU-based runs utilized a multi-core CPU operating at up to 4.3 GHz. The findings highlight that the GPU implementation delivers an improved computational time compared to the CPU-based solution, demonstrating the improvement with the application of GPU-FIFVS approach.

© 2025 Elsevier Masson SASThe increasing demand for ultrafast aerospace transportation and high-performance strategic systems has fueled the interest in air-breathing hypersonic vehicles. However, their design still presents considerable challenges owing to the tight coupling between the thermodynamic and flight dynamic phenomena. This study proposes an integrated simulation framework capable of representing the coupled behavior of a six-degree-of-freedom hypersonic vehicle and a multi-stage scramjet engine model. The proposed framework incorporates atmospheric variation, aerodynamic and mass models, actuator dynamics, and energy-based thrust modeling under transient conditions. The objective was to evaluate the dynamic and thermodynamic responses of a vehicle during flight maneuvers. To that end, several scenarios were simulated, including descent and transition to level flight, acceleration and deceleration. The results demonstrate that the model captures the strong transients associated with ignition, control response, and inlet compression modulation. Thermodynamic analysis revealed consistent heat transfer, irreversibility, and exergy trends, with the combustion stages being the main source of entropy generation. The propulsive efficiency and specific impulse evolve coherently with thrust demand and flight conditions, whereas control logic successfully stabilizes critical thermodynamic parameters during maneuvering. These findings validate the capacity of the framework to reproduce the coupled dynamics of scramjet-powered hypersonic flights, providing a solid basis for future studies on optimization and thermodynamic analysis.

© 2026 by the authors.Turbines experience pressure losses from various sources, one of which is the tip leakage flow in the rotor blades. This is one of the main factors responsible for the decrease in turbine efficiency. This leakage is caused by pressure differences between the blade pressure and suction sides. High-pressure turbines with low aspect ratios and high-pressure loading face critical tip clearance losses, impacting turbine performance. One way to reduce tip leakage flow is to apply the desensitization technique to modify the rotor blade tip geometry. This study aims to apply the desensitization technique to the Energy-Efficient Engine developed by NASA. Different Winglet geometries with varying extensions along the blade tip chord (A— (Formula presented.), B— (Formula presented.), and C— (Formula presented.)), three types of Squealers with different rim dimensions and cavity heights (Squealer A and B), and the same rim thickness and cavity height of Squealer A with a decreased trailing edge region down to (Formula presented.) (Squealer C) were numerically tested. Additionally, the study simulates blending Winglet A with Squealer A (Squealer–Winglet A), Squealer A with Winglet B (Squealer–Winglet B), and Winglet A with Squealer B (Squealer–Winglet C). Numerical simulations are conducted and compared with experimental data. Comparing the various geometries at the design-point pressure ratio, the Winglet A configuration demonstrates an increase of (Formula presented.) in efficiency, Squealer C an increase of (Formula presented.), and for cases involving all Squealer–Winglet models, no improvement was obtained. For (Formula presented.) N at the design-point pressure ratio, Winglet B demonstrates an increase of (Formula presented.) in efficiency, Squealer C an increase of (Formula presented.), and Squealer–Winglet A an increase of (Formula presented.). These are interesting results in the case of the engine operating at cruise condition, in which the rotational speed is around (Formula presented.) N.

© 1965-2011 IEEE.Aviation plays a fundamental and valuable role in the modern world, yet it faces significant challenges, including high fuel costs and substantial environmental pollution. These issues have prompted the aviation industry to establish emission standards and develop less-polluting propulsion systems, such as those utilizing synthetic fuels, fuel cells, and electrification. Among these, electrification holds promise as a potential solution for reducing emissions in commuter aircraft, despite the mass limitations posed by batteries. In this study, a methodology was developed and implemented within in-house software to simulate the performance of a commuter aircraft with a hybrid-electric propulsion system. The analysis focused on key metrics like fuel economy and climb time to cruise altitude. The EMB-120 Brasilia was chosen as the base aircraft for this research. Its long-standing use by the Brazilian Air Force (FAB), the authors' extensive familiarity with its performance, and the availability of experimental data for lift and drag coefficients made it an ideal model for our simulations. To evaluate the performance of the hybrid propulsion system and compare it with the standard case, a gas turbine was utilized as the primary engine. Mathematical models were developed for the PW118 gas turbine, which powers the real aircraft that was considered the standard case, and for the PT6A-68C, which was suggested as a substitute for the hybrid system. To evaluate the aircraft's performance, a standard mission was simulated on a short-range route of 926 km (500 NM), flying at an altitude of 7,620 m (25,000 ft), a common mission that is used by Brazilian Air Force. For hybrid simulations, battery packs were tested with specific energies ranging from 0.125 kWh/kg to 0.750 kWh/kg, in multiples of the initial value. Batteries with 0.250 kWh/kg were considered the current state-of-the-art, while the 0.750 kWh/kg packs represent an extreme upper bound associated with far-future technological developments. The results demonstrated significant performance gains depending on the chosen battery technology and the power split, the hybrid system achieved fuel savings of up to 18% to 19% and reduced climb time by 17% to 25%.

© 2026 The Author(s). International Journal of Applied Ceramic Technology published by Wiley Periodicals LLC on behalf of American Ceramics Society.Multicomponent mesoporous bioactive glass nanoparticles (MMBGs) were engineered to enable coupled ionic and molecular release for controlled ionic and molecular release applications. The nanoparticles (70SiO2–20CaO–4B2O3–3ZnO–3CuO, mol%) were synthesized via a microemulsion-assisted sol–gel route, yielding spherical particles (∼560 nm) with high specific surface area (∼135 m2·g−1) and well-defined mesoporosity. Curcumin was successfully incorporated (∼6 wt%), resulting in reduced surface area and pore volume, consistent with mesopore occupation. Release studies in simulated body fluid revealed a biphasic profile, with ∼80% of curcumin released within 50 h, followed by a sustained release regime. The release behavior is governed by the coupling between glass network depolymerization and mesopore-mediated diffusion. Concurrently, dissolution studies evidenced the progressive release of ionic species (Si, Ca, Zn, Cu, and B), accompanied by pH evolution and surface transformations associated with silica gel formation and apatite nucleation. Structural and surface analyses (XRD, FTIR, XPS, and N2 physisorption) confirmed the preservation of the amorphous network and the role of network-modifying ions in controlling dissolution kinetics. These findings establish a structure–function relationship linking glass composition, structural evolution, and transport processes, highlighting the potential of MMBGs as tunable platforms for controlled ionic and molecular release governed by composition and structure.

© 2026 The AuthorsDespite multimodal therapy, bone tumours can lead to high morbidity and poor survival, with recurrent limited success from trials investigating targeted or immunotherapies. Surgery remains essential and is often the only option available for refractory disease, skeletal metastases, and some benign bone lesions. However, primary bone tumours, such as osteosarcoma, often recur locally when complete resection is hindered by limited safety margins or proximity to vital structures. A multifunctional biomaterial capable of eradicating residual tumour cells while promoting bone regeneration could significantly improve outcomes of surgical procedures in these clinical settings. Here, we report the anticancer and antibacterial properties of gallium-containing bioactive glasses (Ga-BGs). We show that osteosarcoma cell lines are especially sensitive to gallium and that Ga-BGs can release therapeutic levels of gallium ions that selectively kill osteosarcoma cells. Our mechanistic investigation reveals that gallium promotes a multi-pronged molecular attack on key hallmarks of cancer cells, primarily through disrupting iron metabolism leading to increased oxidative stress, induction of cell death pathways, and suppression of oncogenic and metastatic signalling. Moreover, gallium nitrate and Ga-BGs are shown to present inhibitory effects upon gram-negative bacteria P. aeruginosa. Taken together, our results indicate that Ga-BGs constitute a model biomaterial for the development of multi-functional scaffolds for the treatment of osteosarcoma.

© 2026 The Authors.NiTi alloys are well known for their Shape Memory Effect (SME) and are widely used in various fields, including engineering and biomedical applications such as stents. In this study, the corrosion behavior of two solution-treated NiTi alloys with distinct microstructures, martensitic (Ti55Ni) and austenitic (Ti56Ni), was investigated in 0.9% and 3.5% NaCl solutions. The samples were subjected to immersion tests in accordance with ASTM G31–72 for up to 720 h, with monitoring of mass loss, pH variation, and surface characterization by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), along with X-ray diffraction (XRD) to evaluate the post-corrosion structural condition. Electrochemical tests (OCP and Linear Potentiodynamic Polarization) were also conducted to complement the assessment of alloy performance. The results showed low mass loss for both alloys; however, distinct corrosion responses were observed depending on microstructure and testing methodology. The austenitic alloy exhibited lower corrosion rates in immersion tests, whereas the martensitic alloy showed more favorable electrochemical behavior, characterized by more noble corrosion potentials and lower corrosion current densities. Overall, the corrosion behavior of NiTi alloys was found to depend on both microstructure and chloride concentration, with different trends observed under immersion and polarization conditions.

© 2025 The Authors.NiTi shape memory alloy (SMA) bone staples are functional devices that have the unique ability to exert continuous and dynamically active compression, aligning with the mechanobiological factors associated with bone healing. In this work, NiTi SMA alloys produced by electron beam melting were reprocessed to test the manufacturing of porous bone staples prototypes using the rapid investment casting (RIC) process. The results showed that the porous NiTi SMA bone staple exhibited superelasticity at body temperature (37 °C), reducing the compression force by up to 18 % compared to the dense staple, and thereby reducing the risk of stress shielding at the fracture site. Furthermore, we confirmed the presence of the protective passive TiO2 layer, ensuring cytocompatibility of the samples produced by the RIC process. Therefore, it was possible to demonstrate that RIC technology can be used to prototype porous NiTi SMA bone staples with thermomechanical strength and cytocompatibility, including the possibility of customization of the implant to a specific patient, and that this technology can be extended to other NiTi SMA implantable medical devices.

© 2026 The Author(s).The escalating generation of electronic waste (e-waste) poses critical environmental and health challenges, with waste printed circuit boards (WPCBs, 4 wt.%–6 wt.% of e-waste) representing a particularly hazardous fraction due to their complex composition of metals, polymers, and brominated flame retardants. This study explores the valorization of WPCBs as a partial cement replacement to both mitigate disposal risks and enhance cementitious performance. Portland cement pastes incorporating 0 wt.%, 5 wt.%, 10 wt.%, and 15 wt.% WPCBs were examined through isothermal calorimetry, Fourier transform infrared (FT-IR) spectroscopy, and reactive molecular dynamics (RMD) simulations using the reactive force field. Calorimetry revealed that 10% WPCBs yielded the highest heat release (≈25 °C peak, 10% higher than reference), indicating optimal hydration kinetics, while 15 wt.% WPCBs reduced exothermicity by 8% due to inert filler effects and bromine-induced retardation. FT-IR revealed intensified Si–O stretching (953 cm−1) and free O–H (3640 cm−1) at 10 wt.%, confirming enhanced C–S–H and CH formation. RMD simulations provided molecular-level insights, showing denser C–S–H networks and the lowest total energy (−6.82 × 105 kcal/mol) for 10 wt.% WPCBs, whereas 15 wt.% loading disrupted network formation. The integrated findings suggested that WPCBs can be safely immobilized within cement matrices, with 10 wt.% substitution offering a balance between performance gains and hydration integrity. This work advances the understanding of WPCB–cement interactions and supports the development of sustainable, circular-economy construction materials.

© 2026 Taylor & Francis Group, LLC.Increasing environmental regulations are driving the development of green solid propellants with reduced toxicity and lower life-cycle environmental impact. The binder plays a critical role in solid propellants, with hydroxyl-terminated polybutadiene (HTPB) being the most widely used despite its petroleum origin, environmental concerns, and restricted availability. This study evaluates castor oil (CO), a renewable, biodegradable, and low-toxicity resource, as a sustainable alternative binder. A CO-based polyurethane prepolymer containing 30% (w/w) toluene diisocyanate was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), rheology, particle distribution, hardness tests, and scanning electron microscopy (SEM). The results showed 20% faster curing and hardness comparable to HTPB, highlighting the potential of CO as a viable and sustainable binder for solid propellant applications. Additionally, SEM analysis comparing the top and bottom regions of two CO-based samples produced by different synthesis using ammonium perchlorate (AP) as filler demonstrated a more homogeneous AP distribution in the sample #2 (a prepolymer it was first synthesized by reacting CO with 30% of the TDI needed for complete curing).

© 2026, Springer Science and Business Media Deutschland GmbH. All rights reserved.Buildings and structures have been targets of detonations caused by explosives, whether intentional or accidental. Recently, with increasing global concern about terrorist actions and accidents in facilities handling explosives, the study of this area has received significant attention. Among the lethal effects of explosive devices, the blast generated by a detonation produces the most intense loads on structural elements. Consequently, it is important to examine the vibration response of structures under this type of load. This paper presents Finite Element Method (FEM) simulations to predict the blast effect on thin steel sheets and compares the results with detonations from field tests. Six charges of 334 g of Composition B explosive were detonated with standoff distances of 300 mm and 500 mm respectively from 2 mm thick bi-supported A36 steel sheets. The steel sheet displacements and vibrational behavior were measured using high-speed cameras (HSC). The results presented in this paper demonstrate the consistency of FEM simulations when compared with controlled field tests. The main contribution of this work is to advance the academic study of explosive effects on structures through a computational method that is simpler, cheaper, and safer than field blast tests.

© 2026 The AuthorsInconel 718 is crucial in high-demand thermomechanical applications such as components of gas turbines and rocket engines. With an increasing need for complex parts, additive manufacturing, especially Laser Based Powder Bed Fusion of Metals (PBF-LB/M), has become a useful processing route for engineering components. However, the PBF-LB/M process generates out-of-equilibrium solidification, promoting segregation, residual stresses and undesired phases, which compromises mechanical properties, such as fatigue strength. For this reason, PBF-LB/M components usually require post-processing heat treatments. This study evaluates the effectiveness of different single solution heat treatments followed by aging in PBF-LB/M IN718. In addition to the conventional 980 °C-1 h solution treatment, two higher-temperature routes, 1065 °C-1.5 h and 1160 °C-4 h, were investigated as simplified single-step solution treatments prior to aging. The purpose was to assess whether these routes can promote Laves phase dissolution, recrystallization, residual stress modification and acceptable mechanical response without requiring an additional solution heat treatment. It was observed that solution heat treatments at 1065 °C for 1.5 h and 1160 °C for 4 h resulted in recrystallization, with the latter condition even displaying grain growth and high compressive residual stresses at the surface. The conventionally treated condition at 980 °C for 1 h exhibited higher hardness and tensile strength due to increased dislocation density and presence of both Laves and δ-phase. However, even though the conditions at 1065 °C-1.5 h and 1160 °C-4 h present higher tensile strength than the wrought material, it still lacks ductility compared to the wrought material. It is concluded that both solution heat treatments at 1065 °C-1.5 h and 1160 °C-4 h have reached recrystallization and stress relief. Overall, the 1065 °C-1.5 h and 1160 °C-4 h routes showed potential as simplified solution heat treatments followed by aging, producing recrystallized, nearly texture-free and stress-relieved microstructures while retaining significant tensile strength.

© 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.High-temperature oxidation is a major challenge in steel thermomechanical processing, as oxide scale formation reduces performance, increases production costs, and accelerates material degradation. The rate of oxidation is strongly influenced by temperature, and alloy composition, with temperature-dependent behaviors often governed by the formation and stability of protective oxide layers. Classical oxidation models, such as parabolic and linear rate laws, are limited because they assume planar geometries and single-limiting step mechanisms, making them unsuitable for multi-step oxidation or for comparing alloys with distinct oxide compositions. In this study, the Unreacted Shrinking Core Model (USCM) was, for the first time, applied to describe the oxidation rate of four distinct steel alloys (AISI 1045, 1095, 4340, and D6) oxidized between 900 °C and 1200 °C. The model was fitted to experimental data, supported by SEM, EBSD, and XRD characterization. Results show that scale diffusion and mixed diffusion–reaction mechanisms govern oxidation in AISI 1045, 1095, and 4340, while AISI D6 oxidation is primarily surface-reaction controlled due to its high chromium content. Among the alloys, AISI D6 exhibited the highest oxidation resistance, following a reaction-controlled oxidation rate mechanism, while AISI 1095 also showed improved resistance at 900–1000 °C attributed to its high carbon content. The USCM successfully quantified metal-to-oxide conversion as a function of temperature and time, enabling the determination of Arrhenius parameters for reaction rate and diffusivity, which can be extrapolated to different geometries. This geometry-flexible framework makes the USCM highly relevant for optimizing processing parameters such as working temperature, time and alloy composition in industrial applications.

© 2026 by the authors.This study provides the first complete and experimentally validated Yoshida–Uemori (Y–U) parameter set for AA6005C aluminum alloy, enabling accurate constitutive modeling for stamping simulations. A comprehensive set of mechanical tests was conducted, comprising uniaxial tensile tests along 0°, 45°, and 90° to the rolling direction, hydraulic bulge tests, Nakajima tests for the forming limit curve (FLC), and cyclic tension-compression experiments. Results showed moderate planar anisotropy with R-values of 0.49–0.90, equi-biaxial yield stress around 105 MPa, and plane-strain FLC0 ≈ 0.25, typical for 6xxx-series alloys. The cyclic tests highlighted a strong Bauschinger effect and transient softening, which allowed precise calibration of the Yoshida-Uemori (Y-U) model. The resulting material parameters were validated using a U-bending case study, in which the predicted springback angle differed by only 2°, confirming the transferability of the calibrated model to forming conditions not used during parameter identification. The dataset generated in this work provides a robust foundation for finite element simulations of the AA6005C stamping processes and constitutes a practical reference for industrial implementation.

© 2026 The Authors.Strain-induced martensite formation and α′-martensite to austenite reversion (α’ → γ) were investigated in a cryorolled UNS S32304 lean duplex steel. The material was rolled at 77 K up to 50 % thickness reduction and annealed up to 800 °C for 1 h. The microstructural evolution of the steel, with focus on α′-martensite to austenite reversion was followed by several characterization techniques, complemented with thermodynamic calculations. For 50 % reduction, practically all austenite has transformed into α′-martensite. From EBSD and magnetization results, the α′-martensite to austenite reversion occurs in the temperature range of 500–800 °C. At 800 °C, the austenite phase is recrystallized, and presents a bimodal grain size distribution, mainly attributed to the fragmentation of α′-martensite prior to reversion. EBSD and EDS results indicate that the α’ → γ mechanism at 600 °C is likely displacive, while between 700 and 800 °C a gradual transition from a displacive to a diffusional mechanism occurs. From magnetic measurements, a comparison between the cryorolled steel and the same material deformed at room temperature up to 80 % reduction, following annealing, was made. Except at the beginning of the α’ → γ transformation (500–600 °C), cryorolling does not accelerate the reversion of α′-martensite to austenite during annealing, contrary to expectations. However, it has a strong effect on the morphology of reverted austenite. This highlights the possibility of using cryorolling to produce a wider variety of microstructures during thermomechanical processing.

© 2025 Acta Materialia Inc.High solidification rates and in situ heat treatments are commonly found in additive manufacturing (AM) of steels, resulting in a complex and far-from-equilibrium microstructure. Therefore, standard post-processing heat treatments commonly applied to wrought steels can favor the occurrence of different phenomena and can change the phase transformation sequence, due to the unique microstructure obtained by powder bed fusion – laser beam (PBF-LB). This work reports the microstructural evolution of 15-5 precipitation hardening (PH) stainless steel manufactured by PBF-LB during direct aging heat treatments at 621 °C (AMS H1150 standard condition), a route used to increase fracture toughness due to the martensite reversion and precipitates coarsening. The reversion of martensite into a Ni-rich austenite, predicted by kinetic calculations, was confirmed by high-energy X-ray diffraction (HE-XRD), being preferentially nucleated close to the copper-rich precipitates (CRPs), which can act as a preferential nucleation site. CRPs presented an oval shape, as confirmed by electronic microscopy (SEM and TEM) and atom probe tomography (APT). Fast Fourier transform (FFT) analysis of high-resolution TEM (HR-TEM) images suggests CRPs still present the metastable untwined 3R-type structure after 8 h, rather than the most stable FCC structure. The presence of retained austenite, inherent to PBF-LB-processed PH steels, affects the CRPs evolution in different phases, and the CRPs themselves act as nucleation sites for Nb(C,N) secondary precipitation. These findings emphasize the necessity of microstructure-oriented heat treatment routes to unlock the full potential of additively manufactured PH stainless steels.

© IMechE 2025Ducted fuel injection (DFI) is a promising technology that can modify the combustion process in compression ignition engines to mitigate soot formation. By guiding the spray through ducts, air entrainment is enhanced, promoting a more pronounced premixed combustion phase, reducing the diffusion flame, and consequently suppressing soot generation. While previous studies using constant-volume chambers and optical research engines have demonstrated the potential of DFI and the influence of injector geometry on emissions, few have implemented this approach directly in engines due to the substantial modifications required to the cylinder head. This study proposes and evaluates an alternative DFI configuration suitable for light-duty compression ignition engines, implemented without significant modifications to the engine head. Experiments were conducted in a single-cylinder research engine using a sleeve fitted to the injector, aligning the ducts with the nozzle holes. The limited space introduces constraints such as a trade-off between duct length and stand-off distance, and a duct length shorter than the theoretical liquid penetration length. Results show that the configuration with a 3.5 mm stand-off distance achieved up to a 70% reduction in soot emissions compared to the free-spray baseline, while shorter stand-off distances (2.5 and 3.0 mm) were less effective. Although DFI delays ignition, it enhances air entrainment and premixed combustion, ultimately accelerating the combustion process.

© 2025 The Authors. Published by Elsevier B.V.When applying tools for mass production of components with high quality demands, for example in the medical or the automotive sector, ensuring the traceability of the produced parts as well as the correlation of the individual part quality is a major challenge. Quality control in mass production is most frequently referred to a batch wise inspection of single parts. In most cases it is impossible for the employer to trace the quality of an individual part and the respective conditions applied for processing. This is indispensable information to connect parts outside of the tolerances and the corresponding defects to the conditions of the tool and the manufacturing process. An increase of quality in production and consequently a reduction of production waste is achievable by setting the actual processing parameters into relation with the respective produced parts. Therefore, the aim of the presented work was to implement an autonomous sensor system for monitoring stamping and injection molding processes. The system comprises specific sensors for data acquisition concerning the most critical processing parameters such as cavity-specific pressure, mold temperature and closing force as well as ambient conditions and time and location of the tool utilization. Furthermore, a digital shadow is implemented in order to validate the occurrence of defects in the produced part simulating the part production by applying the measured processing parameters. Crucial information about the tool usage is displayed in a clearly arranged dashboard developed to inform about operational outcomes as well as productivity data. In conjunction with a connected marking system, the unique identification of the produced parts is realized. Additionally, all recorded data regarding the production conditions is connected to the respective part in a databank. By this, failure and defect analysis can be executed with high efficiency and future defects can easier be prevented.

© 2026 by the authors.This work proposes an analysis of the capability of three deep learning models—the feedforward neural network (FFNN), long short-term memory (LSTM) network, and physics-informed neural network (PINN)—to identify the parameters of a flexible fixed-wing aircraft using in-flight data. These neural networks, composed of multiple hidden layers, are evaluated for their ability to perform system identification and to capture the nonlinear and dynamic behavior of the aircraft. The FNN and LSTM models are compared to assess the impact of temporal dependency learning on parameter estimation, while the PINN integrates prior knowledge of the system’s governing of ordinary differential equations (ODEs) to enhance physical consistency in the identification process. The objective is to exploit the generalization capability of neural network-based models while preserving the accurate estimation of the physical parameters that characterize the analyzed system. The neural networks are evaluated for their ability to perform system identification and capture the nonlinear behavior of the aircraft. The results show that the FFNN achieved the best overall performance, with average Theil’s inequality coefficient (TIC) values of 0.162 during training and 0.386 during testing, efficiently modeling the input-output relationships but tending to fit high-frequency measurement noise. The LSTM network demonstrated superior noise robustness due to its temporal filtering capability, producing smoother predictions with average TIC values of 0.398 (training) and 0.408 (testing), albeit with some amplitude underestimation. The PINN, while successfully integrating physical constraints through pretraining with target aerodynamic derivatives, showed more complex convergence, with average TIC values of 0.243 (training) and 0.475 (testing), and its estimated aerodynamic coefficients differed significantly from the conventional values. All three architectures effectively captured the coupled rigid-body and flexible dynamics when trained with distributed wing sensor data, demonstrating that neural network-based approaches can model aeroelastic phenomena without requiring explicit high-fidelity flexible-body models. This study provides a comparative framework for selecting appropriate neural network architectures based on the specific requirements of aircraft system identification tasks.

© 2026 Elsevier LtdConcentrated Solar Power (CSP) plants generate electricity by concentrating solar radiation onto a receiver, where a heat transfer fluid absorbs and transports thermal energy to a power cycle. Volumetric solar receivers (VSRs) have attracted attention due to their enhanced heat transfer characteristics and high-temperature capability, which contribute to improved overall system efficiency. Here, the performance of different VSR configurations is investigated numerically, focusing on both uniform and axially graded particle size distributions. Four configurations are analyzed: two with constant particle diameters of 1 mm and 3 mm, and two graded configurations in which the particle diameter varies linearly between these values along the flow direction, either increasing or decreasing. The numerical model employs the thermal non-equilibrium assumption and the Rosseland approximation to simulate radiative heat transfer within the porous medium. A radiation boundary condition was applied at the inlet to model the heat transfer, and verification against analytical solutions showed negligible discrepancies. The study analyzed the effects of different inlet velocities and porosities on these receivers. Results show that lower mass flow rates and porosities increase receiver temperatures. Configurations with the same inlet particle size display similar temperature profiles, with larger particles causing more pronounced differences. For smaller inlet particle sizes, graded configurations with increasing diameter achieve similar temperatures as the uniform case but with lower pressure drops. Moreover, decreasing particle sizes along the flow direction led to faster thermal equilibrium for higher porosities, allowing for more compact receiver designs. These findings provide insights for optimizing solar volumetric absorbers to enhance thermal efficiency in CSP applications.

© 2026 The Author(s).Reducing component weight remains a central objective in aviation to improve aircraft efficiency. Additive manufacturing (AM), particularly laser powder bed fusion (L-PBF), offers near-net shape part production with integrated functionalities, but their integration into aircraft structures requires advanced joining technologies. Refill friction stir spot welding (RFSSW) has emerged as a promising alternative to conventional mechanical fasteners for high-strength aluminium joints. This study benchmarks RFSSW against established mechanical fasteners by assessing quasi-static and fatigue behaviour in AA7075-T6 similar and AA7075-T6 to L-PBF AlSi10Mg dissimilar joints. Fractography was conducted using light optical and scanning electron microscopy to investigate the crack initiation and propagation mechanisms. This work represents, to the best of the authors’ knowledge, the first fatigue investigation on dissimilar L-PBF to wrought aluminium RFSSW joints. Case studies showed that replacing mechanical fasteners with spot welds enables weight savings of 1.3% to 8.8%. The fatigue performance and fracture behaviour of the joints are dominated by strong secondary bending at high fatigue loads and, at lower fatigue loads, constrained by hook defects in RFSSW and fretting at the sheet interfaces in the mechanically fastened joints. For similar AA7075-T6 joints, pin and collar fasteners outperform RFSSW, and solid rivets exhibit superior fatigue strength above 2x105 cycles. For low fatigue loads, RFSSW proved to be a viable alternative to pin and collar dissimilar joints. Overall, the study identifies key failure mechanisms and outlines optimisation strategies for RFSSW assemblies. The systematic comparison facilitates knowledge transfer to other RFSSW applications, supporting the broader adoption of the technology.

© 2026 The AuthorsDue to tailored stiffness distribution and enhanced performance, variable stiffness composites (VSC) have been a recent research focus. Variable angle tow (VAT) panels have improved buckling from curvilinear fiber paths within laminae. However, manufacturing still presents challenges. Overlaps and gaps are common in automated fiber placement (AFP); continuous tow shearing (CTS) may present irregular thicknesses. This work presents an alternative fiber tow path parameterization named the QP (quasi-parallel), inspired by fused filament fabrication (FFF), which generates offset curves from a reference path, minimizing overlaps and gaps, while maintaining constant thickness. Buckling performance is investigated for VAT and QP parameterizations, comparing optimal VSC to constant stiffness composites (CSC). Linear buckling of cylindrical panels is evaluated with a semi-analytical framework based on Sanders’ shell formulation and Rayleigh–Ritz solution, including compression-shear combinations, enabling efficient optimization. Numerous case studies are investigated, considering variations in loading, aspect ratio and panel curvature. Graphical search and simulated annealing (SA) optimization are employed to identify optimal designs. Both QP and VAT parameterizations show buckling improvement over CSC. The QP method delivers up to 40% increases for a square compressed plate. Advantages and limitations, such as the need for tow curvature constraint, are discussed for insights on VSC design.

© 2025 Elsevier LtdThis study explores the thermal behavior and volatilization kinetics of JET A-1 aviation kerosene and Farnesane, a sustainable aviation fuel compound, and their blend through thermogravimetric analysis in an oxidative atmosphere. For such, experiments were conducted under a synthetic air atmosphere at three different heating rates (10, 15, and 20 ℃ min−1), and results showed that Farnesane exhibits high thermal stability up to approximately 80 °C, followed by rapid decomposition, whereas JET A-1 starts decomposing at 35 °C and volatilizes gradually until reaching 109 °C. The minimum energy required for the volatilization process of Farnesane to start taking place is about four times greater than that for JET A-1, i.e. 53.72 KJ mol−1 and 12.67 KJ mol−1, respectively. Activation energy of 8.88 KJ mol−1 was found for the Farnesane-JET A-1 blend, which is a lower than that for pure kerosene, thus revealing a beneficial and synergistic effect between them, which should ease the initial stages of fuel vaporization, since it is of paramount relevance for efficient combustion.

© 2025 Elsevier B.V.The increase in the production of Sustainable Aviation Fuels (SAFs) is essential to promote the decarbonisation of the aviation sector by 2050. In this study, Raman spectroscopy was used as a tool to investigate structural changes in samples of JET A-1, Farnesane, and a 10 % Farnesane blend with JET A-1(designated FarnJET10), exposed to an oxidative atmosphere for 3, 24, and 48 h. The results show that JET A-1 exhibits higher oxidative stability, while Farnesane is prone to degradation, with a rapid decrease in vibrational band intensity across all regions of the spectrum. The FarnJET10 blend exhibited intermediate oxidative behaviour, but the findings indicate that the presence of Farnesane compromises the stability of JET A-1. Principal Component Analysis (PCA) was applied to distinguish the stability and chemical behaviour of the fuel samples. The first two principal components explained 98.91 % of the total spectral variation, with PC1 and PC2 accounting for 85.44 % and 13.47 %, respectively. The PCA scores demonstrated a clear separation between the pure fuels and the blend, highlighting the distinct oxidative responses and structural changes induced by exposure to an oxidising atmosphere. These findings highlight the oxidative vulnerability of the SAF/fossil fuel blend and its effects on fuel stability, which may compromise performance during storage and operational use in aviation systems.

© 2026 The AuthorsDue to tailored stiffness distribution and enhanced performance, variable stiffness composites (VSC) have been a recent research focus. Variable angle tow (VAT) panels have improved buckling from curvilinear fiber paths within laminae. However, manufacturing still presents challenges. Overlaps and gaps are common in automated fiber placement (AFP); continuous tow shearing (CTS) may present irregular thicknesses. This work presents an alternative fiber tow path parameterization named the QP (quasi-parallel), inspired by fused filament fabrication (FFF), which generates offset curves from a reference path, minimizing overlaps and gaps, while maintaining constant thickness. Buckling performance is investigated for VAT and QP parameterizations, comparing optimal VSC to constant stiffness composites (CSC). Linear buckling of cylindrical panels is evaluated with a semi-analytical framework based on Sanders’ shell formulation and Rayleigh–Ritz solution, including compression-shear combinations, enabling efficient optimization. Numerous case studies are investigated, considering variations in loading, aspect ratio and panel curvature. Graphical search and simulated annealing (SA) optimization are employed to identify optimal designs. Both QP and VAT parameterizations show buckling improvement over CSC. The QP method delivers up to 40% increases for a square compressed plate. Advantages and limitations, such as the need for tow curvature constraint, are discussed for insights on VSC design.

© 2026 The AuthorsAdditive manufacturing allows the production of multiphase structures with customizable mechanical properties. This study proposes a unit cell for bimaterial honeycombs, followed by experimental and numerical tests. The honeycombs were fabricated by FFF (fused filament fabrication) material extrusion using PET and PET-CF (PET with short carbon fibers), with tool paths generated directly in FullControl design software. Each beam of the unit cell contains both materials side-by-side (double-wall configuration). The composite content is adjustable by varying the thicknesses of the phases, allowing modulation of equivalent properties. Compression tests evaluated the mechanical behavior, while Asymptotic Homogenization (AH) was used to numerically estimate the equivalent properties. Response surfaces based on AH were developed to estimate variations in equivalent properties as a function of composite content. The experimental and numerical results showed strong agreement. The main contribution of this work is the proposal of honeycombs with tailorable mechanical properties, supported by numerical simulations and experiments. The proposed honeycombs have the potential to modulate mechanical properties, as demonstrated through the design of composite material phases: certain configurations exhibit increased structural performance while maintaining a similar use of expensive reinforcing material in terms of volume fraction. These findings highlight the potential for functionally tailored structures in lightweight engineering applications.

© 2026 The Author(s).The escalating generation of electronic waste (e-waste) poses critical environmental and health challenges, with waste printed circuit boards (WPCBs, 4 wt.%–6 wt.% of e-waste) representing a particularly hazardous fraction due to their complex composition of metals, polymers, and brominated flame retardants. This study explores the valorization of WPCBs as a partial cement replacement to both mitigate disposal risks and enhance cementitious performance. Portland cement pastes incorporating 0 wt.%, 5 wt.%, 10 wt.%, and 15 wt.% WPCBs were examined through isothermal calorimetry, Fourier transform infrared (FT-IR) spectroscopy, and reactive molecular dynamics (RMD) simulations using the reactive force field. Calorimetry revealed that 10% WPCBs yielded the highest heat release (≈25 °C peak, 10% higher than reference), indicating optimal hydration kinetics, while 15 wt.% WPCBs reduced exothermicity by 8% due to inert filler effects and bromine-induced retardation. FT-IR revealed intensified Si–O stretching (953 cm−1) and free O–H (3640 cm−1) at 10 wt.%, confirming enhanced C–S–H and CH formation. RMD simulations provided molecular-level insights, showing denser C–S–H networks and the lowest total energy (−6.82 × 105 kcal/mol) for 10 wt.% WPCBs, whereas 15 wt.% loading disrupted network formation. The integrated findings suggested that WPCBs can be safely immobilized within cement matrices, with 10 wt.% substitution offering a balance between performance gains and hydration integrity. This work advances the understanding of WPCB–cement interactions and supports the development of sustainable, circular-economy construction materials.

© 2026 Taylor & Francis Group, LLC.Increasing environmental regulations are driving the development of green solid propellants with reduced toxicity and lower life-cycle environmental impact. The binder plays a critical role in solid propellants, with hydroxyl-terminated polybutadiene (HTPB) being the most widely used despite its petroleum origin, environmental concerns, and restricted availability. This study evaluates castor oil (CO), a renewable, biodegradable, and low-toxicity resource, as a sustainable alternative binder. A CO-based polyurethane prepolymer containing 30% (w/w) toluene diisocyanate was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), rheology, particle distribution, hardness tests, and scanning electron microscopy (SEM). The results showed 20% faster curing and hardness comparable to HTPB, highlighting the potential of CO as a viable and sustainable binder for solid propellant applications. Additionally, SEM analysis comparing the top and bottom regions of two CO-based samples produced by different synthesis using ammonium perchlorate (AP) as filler demonstrated a more homogeneous AP distribution in the sample #2 (a prepolymer it was first synthesized by reacting CO with 30% of the TDI needed for complete curing).

© The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2026.This study uses Reactive Molecular Dynamics (RMD) and Density Functional Theory (DFT) to investigate the properties and decomposition mechanisms of two thiadiazole-furazan compounds, nitrothidiazolefurazan (NTF) and nitrobithidialozolefurazan (NBTF), as potential high-energy-density materials. RMD simulations revealed their thermal stability and initial decomposition pathways, while DFT provided insights into structures, electronic properties, and bond orders, as well as mechanistic support. Results indicate the suitability for extreme conditions in defense or space applications, advancing understanding and design of new energetic materials.

© 2026, AIAA International. All rights reserved.In recent years, economic and sustainability requirements have guided aircraft design toward high-aspect-ratio wings and lighter materials. These modifications have introduced more pronounced coupling between aeroelasticity and flight dynamics, leading to challenges concerning handling qualities. Current techniques for analyzing handling qualities, such as the Cooper–Harper and pilot-induced oscillation (PIO) rating scales, often rely on flowchart-based assessments susceptible to pilot bias. To address this issue, we propose maintaining the use of these rating scales while performing predefined tasks. We also suggest correlating the energy content of the input command power spectral density (PSD) with the respective Cooper–Harper and PIO ratings. The study uses the identified model of the SB-10 sailplane from the German Space Center (DLR), implemented in the Flight Test Simulator (FTS) of the Brazilian Air Force’s Institute of Research and Flight Test (IPEV). The analysis highlights a deterioration in handling qualities due to the increment of the number of structural modes explicitly modeled, emphasizing the importance of considering aeroelastic characteristics in the aircraft design phases before flight test campaigns. The findings suggest the necessity of advanced simulation tools that incorporate these factors to predict, assess, and mitigate handling quality deficiencies effectively during earlier phases of aircraft design.

© 2026 by the authors.This work proposes an analysis of the capability of three deep learning models—the feedforward neural network (FFNN), long short-term memory (LSTM) network, and physics-informed neural network (PINN)—to identify the parameters of a flexible fixed-wing aircraft using in-flight data. These neural networks, composed of multiple hidden layers, are evaluated for their ability to perform system identification and to capture the nonlinear and dynamic behavior of the aircraft. The FNN and LSTM models are compared to assess the impact of temporal dependency learning on parameter estimation, while the PINN integrates prior knowledge of the system’s governing of ordinary differential equations (ODEs) to enhance physical consistency in the identification process. The objective is to exploit the generalization capability of neural network-based models while preserving the accurate estimation of the physical parameters that characterize the analyzed system. The neural networks are evaluated for their ability to perform system identification and capture the nonlinear behavior of the aircraft. The results show that the FFNN achieved the best overall performance, with average Theil’s inequality coefficient (TIC) values of 0.162 during training and 0.386 during testing, efficiently modeling the input-output relationships but tending to fit high-frequency measurement noise. The LSTM network demonstrated superior noise robustness due to its temporal filtering capability, producing smoother predictions with average TIC values of 0.398 (training) and 0.408 (testing), albeit with some amplitude underestimation. The PINN, while successfully integrating physical constraints through pretraining with target aerodynamic derivatives, showed more complex convergence, with average TIC values of 0.243 (training) and 0.475 (testing), and its estimated aerodynamic coefficients differed significantly from the conventional values. All three architectures effectively captured the coupled rigid-body and flexible dynamics when trained with distributed wing sensor data, demonstrating that neural network-based approaches can model aeroelastic phenomena without requiring explicit high-fidelity flexible-body models. This study provides a comparative framework for selecting appropriate neural network architectures based on the specific requirements of aircraft system identification tasks.

© 2026 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license. http://creativecommons.org/licenses/by/4.0/In this paper, the discontinuous Bubnov-Galerkin spectral element method (DBG-SEM) has been used to spatially discretise the first order form of the neutron transport (FONT) equation. A discrete ordinate (SN[jls-end-space/]) approximation is also used to discretise the angular variables and the multigroup approximation has been used to discretise the energy variable. The DBG-SEM has been compared against the discontinuous Bubnov-Galerkin finite element method (DBG-FEM) using two benchmark verification test cases. This is the first time that a detailed comparison of DBG-SEM and DBG-FEM has been completed in the context of the FONT equation. The method of manufactured solutions (MMS) has been used to investigate the convergence rate of the proposed discretisation schemes. This demonstrates that both the DBG-SEM and DBG-FEM yield the same rate of convergence with increasing polynomial order. Both the DBG-SEM and DBG-FEM were used to solve the OECD/NEA two-dimensional (2D) C5G7 nuclear reactor physics benchmark verification test case. Again both methods yield a similar level of numerical accuracy using both straight-sided and curvilinear elements. This analysis of the local element matrix condition number demonstrates that the DBG-SEM yields a lower condition number than the DBG-FEM. Finally, multidimensional anisotropic dispersion and dissipation analysis (MA-DDA) was utilised to understand the dispersion and dissipation errors of the DBG-SEM and DBG-FEM. This is the first time that DDA has been utilised for analysing the dispersive and dissipative properties of spatial discretisation methods for the FONT equation in multidimensions. This analysis demonstrated that the DBG-SEM and DBG-FEM have similar dispersion and dissipative behaviour when exact element integration was used, which is an expected result.

© The Author(s) 2026.This work presents an efficient analytical method for spur gear modelling based on the interpolation of precomputed power-law parameters to calculate contact forces. The motivation arises from the fact that, when a nonlinear contact expression is combined with the linear deformations of the tooth body, the resulting force must be obtained through an iterative procedure to ensure deformation compatibility, which increases computational cost. To overcome this, a preprocessing stage is introduced together with the assumption that, for a meshing situation, the force-penetration relation can be represented by a power-law combining the linear stiffnesses of the tooth bodies with the nonlinear contribution of local contact. In this stage, a database is generated by fitting the power-law parameters for all combinations of contacting points between the teeth. Then, during simulation, the position and rotation of the gears directly provide the penetration and active contact points, from which the corresponding parameters are interpolated within the database, and the force is evaluated through the power-law. This strategy eliminates the iterative compatibility procedure required in the traditional approach when nonlinear contacts are included, inherently reducing the computational time while preserving accuracy.

© ASM International 2025.Energy transition has brought tighter requirements to high-performance gears, especially the demand for increased power density. Usually applied after grinding, isotropic superfinishing stands for a solution to reduce flank roughness and consequently the contact stresses. The objective of this study is comprehending how the residual stresses induced by the grinding process influence the superfinished surface integrity. Specimens were pointedly ground to induce distinct residual stress states in terms of maximum intensity, surface heterogeneity, and in-depth profile. They were then subjected to isotropic superfinishing in a single condition. The investigation showed that, after the isotropic superfinishing, the ground residual stress state is preserved. The results of both intensity and heterogeneity of residual stresses demonstrate that the superfinished surface is strongly influenced by the previous manufacturing stage, to which the proposed mechanism of interaction is verified.

© 2026 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license. http://creativecommons.org/licenses/by/4.0/This paper addresses the modeling of acousto-elastic periodic structures with strong fluid–structure interaction, i.e., lattices in which both solid materials and heavy fluids coexist, and their mutual interactions cannot be neglected. Modeling is conducted with a single unit cell of the lattice using a novel Generalized Bloch Mode Synthesis combined with the Wave-based Finite Element Method (WFEM). Reduced-order unit cell models are derived through a multi-step model order reduction (MOR) procedure, duly accounting for the coupled dynamic behavior at fluid–structure interfaces and enabling exact enforcement of the Bloch–Floquet theorem. These reduced-order models are used within the WFEM framework to quickly obtain accurate responses, without encountering numerical issues. Various unit cell geometries are examined, ranging from simpler to more complex, with fluid confined to internal cavities or distributed throughout the lattice. Both water and mercury are considered as fluids in simulations. Results demonstrate that highly reduced unit cell models are obtained with the proposed MOR strategy; accurate solutions are achieved when the reduced-order models are combined with the WFEM; the dynamic behavior of a manufactured periodic structure with confined fluid is accurately assessed; and the modeling framework performs very well irrespective of the unit cell geometry, symmetry and fluid type.

© 2026 The Author(s).Sustainable aviation fuels (SAFs) are a critical pathway for reducing carbon dioxide (CO2) emissions from the aviation sector, yet the deployment of new SAF candidates requires a robust understanding of their fundamental combustion behavior. Limonene, a renewable terpene derived from pine and citrus biomass, has emerged as a promising candidate due to its favorable energy content and bulk properties relative to conventional Jet A-1. However, despite increasing interest, fundamental premixed combustion data for limonene—particularly laminar burning velocity and flame stability parameters—remain limited. The aim of this study is to address this gap through an experimental investigation of the premixed combustion characteristics of limonene. Laminar burning velocity measurements were performed in spherical and cylindrical constant-volume reactors at atmospheric pressure and unburned-gas temperatures of 358, 398, and 438 K using Schlieren imaging. Experiments were conducted for pure limonene, the Jet A-1 surrogate fuel MURI-1, and a 70/30 (vol./vol.) MURI-1–limonene blend over equivalence ratios from 0.7 to 1.4. The results show that pure limonene exhibits high laminar burning velocities, reaching peak values of approximately 70 cm s⁻1, exceeding those of conventional kerosene surrogates. Flame stability analysis reveals that limonene flames become increasingly sensitive to stretch under fuel-rich conditions, as indicated by decreasing Markstein length and Lewis number. Blending limonene with MURI-1 yields intermediate burning velocities and improves flame stability through increased Markstein length, despite a modest reduction in flame thickness, with enhancements of up to 8% observed under rich conditions. These findings provide new fundamental combustion data for limonene and demonstrate combustion trends consistent with other SAF candidates, supporting its potential as a viable component for future ASTM-certified sustainable aviation fuel formulations and for the development of validated chemical-kinetic models.

© 2026 IAA. Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.AbstractScramjet engines offer great potential for hypersonic propulsion and space access, but efficient combustion remains challenging due to the extremely short residence time for fuel–air mixing and burning. This study presents a parametric investigation of a cavity flameholder with upstream transverse hydrogen injection applied to the HyShot-IV scramjet combustor geometry, using RANS-based CFD simulations in Ansys CFX. The model incorporates the k[jls-end-space/]–ω SST turbulence model and the Burning Velocity Model to analyze the impact of cavity aspect ratio (AR) on key performance parameters, including mixing efficiency, combustion-chamber efficiency, flame stabilization, and pressure recovery. Six configurations were examined: one baseline without a cavity and five cavity cases with (Formula presented). Results demonstrate that cavity flameholders significantly enhance combustion performance by generating recirculation zones, stabilizing the flame, and intensifying turbulence, which collectively promote efficient fuel–air mixing, and these favorable effects are further amplified with increasing AR. Case E ((Formula presented) ) achieved the highest performance, with mixing and combustion efficiencies of 72.3% and 72.5%, respectively, at the expense of a moderate reduction in pressure recovery to 53.8%. Conversely, smaller cavities, such as in Case A ((Formula presented) ), provided limited mixing improvements, with a mixing efficiency of 55.9%, yet retained higher pressure recovery at 56.7%. Key flow features observed include shear layers, cavity expansion shocks, and counter-rotating vortex pairs (CVPs), which interact with shock waves and boundary layers to enhance fuel distribution and combustion. Larger cavities, such as in Cases D ((Formula presented) ) and E, promoted earlier hydrogen consumption and sustained combustion zones. The baseline configuration, lacking a cavity, exhibited the lowest performance metrics, with poor mixing efficiency (51.3%) and delayed combustion, underscoring the importance of cavity-induced structures for efficient scramjet operation.

© The Author(s), 2026. Published by Cambridge University Press.A linear theory for unsteady aerodynamic effects of the actuator line method (ALM) is developed. This theory is validated using two-dimensional ALM simulations, where we compute the unsteady lift generated by the plunging and pitching motion of a thin aerofoil in uniform flow, comparing the results with Theodorsen’s theory. This comparison elucidates the underlying characteristics and limitations of ALM when applied to unsteady aerodynamics. Numerical simulations were conducted across a range of chord lengths and oscillation frequencies. Comparison of ALM results with theoretical predictions shows consistent accuracy, with all Gaussian parameter choices yielding accurate results at low reduced frequencies. Furthermore, the study indicates that selecting a width parameter ratio of ε/c (the Gaussian width parameter over the chord length) between 0.33 and 0.4 in ALM yields the closest alignment with analytical results across a broader frequency range. Additionally, a proper definition of angle of attack for a pitching aerofoil is shown to be important for accurate computations. These findings offer valuable guidance for the application of ALM in unsteady aerodynamics and aeroelasticity.

© 2026, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.The Actuator Line Method (ALM) is coupled with the Vortex Lattice Method (VLM) in order to create a novel methodology titled Vortex-based Actuator Lattice Method (VALM), in which the viscous vortices are placed on the quarter-chord of each panel while the control points are fixed on the three-quarter chord of said panels. The VALM is tested initially for two-dimensional applications employing a flat plate modeled by both one and multiple panels. Initial results show good adherence to the solutions obtained by the thin airfoil theory as well as a traditional VLM code, though this method should be further tested to fully assess its potential. The proposed method shows potential to be used in simulations where the ALM is widely employed, such as complex flows involving wind turbines and aeronautical rotors, with the added benefit of allowing discretization along the chord.

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.The joint 8th Drag Prediction Workshop (DPW-8) and 4th Aeroelastic Prediction Workshop (AEPW-4) evaluate computational aeroelastic analysis and drag predictions for aircraft. The initiative promotes collaboration between aerodynamics and aeroelasticity communities, focusing on enhancing simulation methodologies based on the Common Research Model (CRM), a benchmark aircraft supported by extensive experimental and finite element data. The ITA-Embraer team is developing a fluid-structure interaction (FSI) framework using SU2 as the computational fluid dynamics (CFD) solver and MSC Nastran for the finite element method (FEM) solver. A major challenge in this process is the high computational cost due to the fine structural mesh provided by NASA, which increases simulation time during iterative FSI coupling cycles. To address this, a coarser FEM mesh was proposed and validated through detailed comparisons with the original high-fidelity model. Results demonstrated strong agreement in natural frequencies and mode shapes, confirming that the reduced mesh preserves essential structural dynamics and statics characteristics. Additionally, the FEA runtime was reduced by approximately 60%, significantly improving computational efficiency without compromising result quality.

© The Author(s), 2026. Published by Cambridge University Press.Collaborative robots (cobots) have emerged as a pivotal paradigm for the upcoming leap to Industry 5.0. In recent years, the range of applications has expanded significantly, particularly in assembly tasks within the manufacturing industry. The primary goal of this paper is to review the application of cobots in industrial assembly tasks, highlighting possibilities for innovative research in smart robotics, including prospects for challenging applications in aircraft final assembly processes. The paper systematically reviews recent literature to analyse the use of collaborative robotics in industrial assembly tasks, encompassing characterisation of application environments, motivations, characteristics and outcomes of relevant use cases across various industrial segments. Additionally, it reviews a set of innovative technological patents issued by the aeronautical industry over the past 14 years, highlighting trending projects in industry. The investigation reveals that the automotive and electronics industries remain at the forefront of cobot applications, mainly for tasks like pick-and-place operations and component manipulation. Applications in open work cells, where humans and robots operate at supportive or sequential interaction levels, using conventional communication interfaces and camera-assisted technologies, have been the most prevalent. The review identifies potential opportunities and key aspects from future application scenarios for cobots. The findings are relevant to the industrial robotics community, emphasising the need for novel applied research on human–robot colla boration in aeronautical industry.

© 2026 IEEE.This paper brings the architecture for a ROSbased Hardware Abstraction Layer (HAL) to interface with the devices of a mechatronic end-effector. A HAL is a middleware between an application and the hardware, responsible for abstracting low-level operations for the client applications. A key feature of this approach is the scalability and modularity delivered by the ROS framework. To illustrate this, the paper presents a case study related to the modeling and integration of a critical-safety gripping function of the given robotic end-effector. This function is modelled and simulated using the timed automata formalism in UPPAAL, which is then implemented within the HAL using the proposed architecture. The system's HAL controller is implemented and tested directly on the Toradex Verdin hardware. The results highlight how this design approach enables the early verification of critical mechatronic functions in robotic systems.