Purpose The low surface hardness and wear resistance of TA15 alloy limit their applications. The purpose of this study is to enhance the surface mechanical properties of TA15 alloy via carbide coating protection, while guaranteeing the adhesion between the substrate and coatings. Design/methodology/approach First-principles calculations were used to predict the temperature-dependent elastic and thermodynamic properties of the ZrC system. The ZrC coatings were fabricated using double glow plasma alloying (DGPA) technology. Findings Theoretical calculations indicate that ZrC system exhibits promising elastic and thermodynamic properties. The experimental hardness of ZrC coatings prepared using DGPA technology closely matches their theoretical hardness, reaching 25.2 ± 1.1 GPa, while the coating adhesion exceeds 50 N. The tribological test results indicate that the wear rate of the ZrC coatings is (3.9 ± 0.2) × 10−6 mm3/(N·m), representing an improvement of 99.3 % compared to the substrate. Originality/value The combination of theoretical prediction and experiments is an effective strategy in materials research. The ZrC coatings prepared using DGPA technology effectively enhance the mechanical properties of TA15 alloy. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2025-0429/

Investigating the influence of solvent molecular structure on the separation of α-olefins in Fischer-Tropsch naphtha.

Using diffusion-induced growth instabilities to measure line tension at liquid condensed-liquid expanded domain boundaries.

Microplastics affect marine snow formation and sinking to the ocean's interior.

The motion of a particle sliding on a frictionless surface of revolution z(r) subject to a uniform gravitational field can be reduced to a one-dimensional radial motion governed by an “effective analogous potential energy function” (EAPEF), similar to the effective potential energy function used in two-dimensional problems with radial symmetry. The EAPEF depends on the angular momentum and total energy of the particle, and thus on the initial conditions of the motion. The general expression for the EAPEF is derived and the EAPEF is used to find the radial equation of motion, the condition for circular orbits on the surface, and the period and stability of those orbits. For stable circular orbits, the EAPEF is used to find the period of small radial oscillations in a perturbed but stable circular orbit. By comparing the period of the circular orbit with the period of small radial oscillations, the conditions for which the perturbed orbit will be periodic are derived. The period of more general radial oscillations, as well as the average orbital period, is given in terms of integrals involving the EAPEF, which can be computed numerically and used to find periodic orbits with large radial oscillations. We show results obtained by applying this technique to a variety of surfaces, as well as experimental results for a spherical pendulum that shows reasonable agreement with theoretical predictions. The EAPEF is a useful tool for analyzing motion on surfaces of revolution, and can be used as the basis for interesting student projects.

This study investigates the propagation of laser beams within Fabry–Perot resonators bounded by circular apertures. We present two independent analytical methods that can be shared with students for determining the transverse eigenmodes of such resonators, one based on the solution of the paraxial Helmholtz equation and the other employing the Huygens–Fresnel integral formulation. Complementing the theoretical analysis, we designed an undergraduate-level experiment using a half-symmetric plano-concave Fabry–Perot resonator. In this setup, Laguerre–Gaussian mode patterns were generated and compared with the theoretical predictions. The approach enhances students' understanding of resonator optics and fosters deeper engagement with experimental physics.

Theoretical prediction model for dust explosion pressure and flame propagation in vessel–pipeline systems under airflow transport conditions

K2P channels and ultrasound neuromodulation: A mechanosensitive memory perspective.

Theoretical predictions of the decay rate change of the 40K nucleus

Theoretical prediction modeling of residual pre-tightening force of bolt group of aerospace engine casing system considering gap and coaxiality deviation

This work presents a novel demonstration of the optical Faraday effect using spatially coherent sunlight, providing an alternative to traditional laser-based approaches. The beam was directed through a Terbium Gallium Garnet (TGG) magneto-optic crystal under a tunable magnetic field (-0.5 to 0.5 T). The polarization rotation was visualized through a linear polarizer that produced a split-lobe intensity pattern whose angular shift was directly related to the applied magnetic field. Experimental results showed a linear dependence of the rotation angle on the magnetic field magnitude and were in close agreement with theoretical predictions. This work validates the feasibility of utilizing natural sunlight for high-precision magneto-optic experiments, overcoming the limitations associated with artificial coherent sources. The methodology not only advances the fundamental understanding of light-matter interactions but also highlights practical applications in developing field-deployable optical devices such as magnetic field sensors and sunlight-powered isolators. By combining classical magneto-optic principles with innovative imaging techniques, this research opens avenues for sustainable, cost-effective optical technologies that utilize natural light sources.

ABSTRACT Infrared optical materials are critical for numerous applications, yet accurately characterizing their intrinsic optical properties remains challenging. Traditional theoretical approaches—ranging from empirical molecular dynamics to first‐principles methods like density functional perturbation theory (DFPT)—face trade‐offs between accuracy and computational cost, particularly for complex or low‐symmetry material systems. Here, we tackle these challenges by introducing a fast and accurate infrared spectroscopy computational framework using machine learning interatomic potentials. By leveraging machine‐learned interatomic forces, this method bypasses costly higher order DFPT calculations, enabling rapid extraction of phonon vibrational parameters. These parameters are then integrated into infrared‐active vibration models to compute dielectric functions and infrared optical properties. Validated across diverse materials, our proposed framework demonstrates broad applicability while achieving a drastic reduction in computational cost compared to conventional methods. This framework bridges the gap between experimental characterization and theoretical predictions, offering a scalable tool for high‐throughput screening and design of infrared optical materials.

This paper investigates the application of negative stiffness systems for vibration isolation in civil engineering applications, particularly focusing on pipelines, buildings, and bridges subjected to dynamic loads such as earthquakes, traffic vibrations, and wind forces. These systems, which function by counteracting external forces, have the potential to enhance the structural resilience of infrastructure. The research integrates both mathematical modeling and experimental testing to assess the vibration isolation characteristics of negative stiffness systems. The methodology follows the approach introduced by Adar et al. (2022) in his study of negative stiffness systems for vibration isolation in pipelines. Finite element analysis (FEA) is used to model the system and predict its behavior under dynamic loads, while experimental setups validate the theoretical predictions. By comparing the results from both approaches, the study demonstrates the effectiveness of negative stiffness systems in isolating vibrations across different frequency ranges, particularly where traditional vibration isolation techniques, such as mass-spring dampers or viscoelastic materials, fall short. The findings indicate that negative stiffness systems can achieve substantial vibration reduction, making them a highly viable solution for enhancing structural performance in dynamic environments. These results contribute to advancing the use of negative stiffness technologies in civil engineering, paving the way for more efficient vibration isolation systems in infrastructure that faces extreme dynamic loading conditions. The study provides insights for future research in the integration of negative stiffness in resilient infrastructure design.

We move our eyes and head to sample the visual environment. While these movements are essential for survival, they greatly complicate the analysis of retinal image motion. Our brain must account for the visual consequences of self-motion to perceive the 3D layout and motion of objects in a scene. We show that traditional models of visual compensation for eye movements fail when the eye both translates and rotates, and we propose a theory that computes both motion and depth in more natural viewing geometries. Consistent with our theoretical predictions, humans exhibit distinct perceptual biases when different viewing geometries are simulated by optic flow, and these biases occur without training or feedback. A neural network model trained to perform the same tasks suggests that viewing geometry modulates the joint tuning of neurons for retinal and eye velocity to mediate these adaptive computations. Our findings unify previously separate bodies of work by demonstrating that the brain adaptively perceives the dynamic 3D environment according to viewing geometry inferred from optic flow.

Abstract The integration of high-temperature superconductors (HTS) into electric propulsion systems, particularly Magneto-Plasma-Dynamic Thrusters (MPDTs), has recently garnered significant attention. However, research on low-power HTS-based MPDTs, which are crucial for small satellites and CubeSats, remains limited. The increasing demand for compact, high-efficiency propulsion in Low Earth orbit underscores the need for scalable HTS-AF-MPDT systems operating below 15 kW. Despite this, challenges such as the lack of detailed theoretical models, limited plasma diagnostics, and excessive Joule heating in conventional copper magnets persist. In this work, using a downscaled version of a 25 kW high-temperature superconducting (HTS) based applied-field magneto-plasma-dynamic thruster, we address these limitations by developing and experimentally validating a theoretical MHD-based plasma acceleration model for an AF-MPDT equipped with a conduction-cooled HTS magnet.The system achieves a specific impulse of 3265s at an input power of 12 kW, more than eight times higher than traditional chemical propulsion, alongside a thrust of 320mN and an efficiency of 25% at sub 12kW. The HTS magnet reduces magnetic power consumption from 285 kW to under 1 kW and lowers magnet mass from 220 kg to 60 kg, enabling substantial improvements in system miniaturization and efficiency. These results represent the first reported demonstration of a 12kW high-temperature superconducting AF-MPDT, bridging theoretical predictions with experimental outcomes and laying the groundwork for in-orbit demonstration of high-performance propulsion for small satellites.

Lowering the overpotential for the oxygen-evolution reaction (OER) is central to designing efficient water-splitting catalysts. However, the atomistic origin behind the enhanced OER activity of hollandite IrO2 compared to rutile has remained unclear. Here, using grand-canonical DFT with an implicit solvation model, the electrochemical stability and reactivity of the most stable hollandite facets, (100) and (112) are elucidated. The thermodynamic analysis identifies that hollandite is more readily oxidized than rutile under the working potential of 1.6V and predicts potential-driven deintercalation of K+ from Hol(112) surface. Fully K-deintercalated hollandite surfaces exhibit lower overpotentials than rutile (110) due to local lattice distortions that enhance π-bonding with *O species. Additionally, the hollandite (112) surface possesses an exceptionally low O2 desorption energy of 0.45 eV (less than half that of rutile), pointing to a highly efficient O2-release process. The theoretical predictions clarify the atomistic origin of the experimentally observed OER reactivity of the hollandite phase and provide deeper insight into structure-activity relationships in hollandite IrO2, providing rational design strategies for next-generation OERcatalysts.

Abstract We report on an experimental and theoretical investigation of the Poggendorff balance, which is an Atwood machine attached to a weight balance devised by J. C. Poggendorff. We have designed and constructed a modern version of the apparatus in which the Atwood machine (with a finite‐mass pulley) is attached to a rigid aluminum rod with a counterweight, with its equilibrium maintained by a small thread holding the pulley motionless. Upon burning, the small thread disappears, and the system undergoes motion. On the one hand, we measure the time-dependent angle α(t) of the balance arm with respect to the horizontal using a potentiometer–Arduino assembly and record data at high temporal resolution. On the other hand, theoretical predictions are obtained via the following approaches: a Newtonian analysis accounting for the pulley's mass and non‑inertial effects; and two Lagrangian formalisms for “parallel” and “perpendicular” pulley orientations, each numerically integrated in a simple program developed in Fortran. All three models yield nearly identical results, and they are in qualitative agreement with the experimental results. Quantitative deviations are attributed to the manual synchronization of thread burnout and data capture, as well as frictional effects in the potentiometer. As a secondary goal, we discuss the educational value of this historically neglected experiment in illustrating the distinction between force as cause versus consequence of motion and argue for its pedagogical utility in comparing Newtonian and Lagrangian formalisms. Future work will focus on full automation and synchronization.

Binary mixtures of HFE-73DE and ethyl acetate are investigated as dielectric working fluids for laminar minichannel cooling. Thermophysical properties of the pure components and four mixtures (10/90, 25/75, 50/50 and 75/25 mass % HFE-73DE/ethyl acetate) were measured over the relevant temperature range. Single-phase convective heat transfer tests were then carried out in a heated 1 × 4 × 180 mm minichannel test section under constant heat-flux conditions for pure HFE-73DE. A three-dimensional conjugate CFD model with temperature-dependent liquid properties was developed in Simcenter STAR-CCM+ and validated against these measurements; the average relative temperature difference between CFD and experiment remained below 0.5%, while a grid-convergence study based on the Grid Convergence Index (GCI) confirmed that the numerical uncertainty is comparable to the experimental one. The validated model was subsequently used to predict the axial evolution of wall temperature, fluid-core temperature, velocity and heat transfer coefficient for the four mixtures under identical conditions. The mean Nusselt numbers obtained from CFD were further compared with the classical Shah and London fully developed laminar solution for rectangular ducts, revealing that the present configuration yields values about 35–42% higher than the theoretical prediction owing to asymmetric heating and conjugate heat transfer. The results show that increasing the HFE-73DE mass fraction strengthens convective heat transfer and reduces fluid-temperature rise, while intermediate compositions (50/50 and 75/25) provide a favourable compromise between enhanced heat transfer performance and moderate pressure drop. The study provides guidance for composition selection and the design of dielectric minichannel heat exchangers operating with HFE-73DE/ethyl acetate mixtures.

Monolayer transition metal dichalcogenides (TMDs) are a key class of two-dimensional (2D) materials with broad technological potential. Their Janus counterparts exhibit unique properties due to broken out-of-plane symmetry and further enrich the functionalities of TMDs. However, experimental synthesis and identification of Janus TMDs remain challenging. It is thus highly desirable to have a rapid, simple, and in situ characterization technique to monitor, in real time, the conversion process from the parent to Janus structure. Raman spectroscopy stands out for such a task as it is a powerful, nondestructive, and very commonly used tool to characterize 2D materials both in situ and ex situ. To realize the full potential of Raman spectroscopy on rapid characterization of Janus TMDs, we present a computational "Raman digital twin" library for various monolayer Janus TMDs in both 2H and Td phases. We focus on group-6 TMDs: MoS2, WS2, MoSe2, WSe2, MoTe2, WTe2 and their Janus variants: MoSSe, MoSTe, MoSeTe, WSSe, WSTe, and WSeTe. Using first-principles density functional theory (DFT), we calculate their vibrational properties and predict distinct Raman fingerprints. These phonon and Raman signatures reflect each material's structural symmetry and atomic composition, enabling clear identification via Raman spectroscopy. Our theoretical work supports experimental efforts by providing benchmarks for material identification, structural analysis, and quality control. The computational library expedites the discovery and development of Janus 2D materials, facilitating tighter integration between theoretical predictions and experimental validation.

This study introduces a systematic coarse-graining approach to model poly(ε-caprolactone) (PCL) in its melt state. The primary goal is to provide a simple and adaptable method for creating computational models of biodegradable polymers, which can then be used to study materials with a wide range of molecular weights and compositions that are relevant to industry. This research addresses the growing need for sustainable materials across various industrial applications. To study long polymer chains, the L-OPLS force field, an adapted version of the OPLS-AA force field, was used for atomistic simulations. The data from these simulations were first thoroughly checked against existing literature and theoretical predictions to ensure their validity. These validated atomistic configurations then became the foundation for developing the coarse-grained model. The research meticulously measured both the structural and dynamic properties of the PCL at the atomistic and coarse-grained levels. The findings show that the model is successful at accurately reproducing key characteristics across these different levels of resolution. The methodology presented in this work aims to facilitate the development of computational studies that can help optimize the properties of PCL-based materials. By doing so, it has the potential to reduce the environmental and economic impact of developing new sustainable materials.