ABSTRACT To address the challenge of inefficient synthesis of multi‐principal‐element transition metal carbides, this study demonstrates an efficient pathway using ultrafast high‐temperature sintering (UHS) to convert elemental precursors into dense, 2‐ to 9‐component solid solutions within minutes. Rapid densification results from a synergy between the high heating rate of UHS and the formation of a Cr 3 C 2 ‐based liquid phase. The formation of a single‐phase solid solution is governed by a thermo‐kinetic control mechanism, where thermodynamic drivers are ultimately constrained by kinetic barriers, such as the poor solubility of key components (e.g., ZrC) and the diffusion‐facilitating role of carbon vacancies. The resulting solid solutions exhibit excellent hardness (up to 38.6 GPa), but their fracture toughness is limited by process‐induced thermal stresses, a drawback partially mitigated by post‐sintering annealing. This work presents a promising approach for the high‐throughput fabrication and screening of these materials and provides critical insights into their non‐equilibrium sintering mechanisms.

Impact boiling in real liquids under intense heating rates

This study establishes a microscopic physical model of the NCM622 cathode electrode sheet based on the discrete element method (DEM). Through numerical simulation, the effects of roller speed, heat source temperature, and electrode material composition ratio on the thermal conduction behavior during the hot roller pressing process are quantitatively analyzed. The influence of the binder on the heat transfer of the electrode sheet is also taken into account. The simulation results indicate that for the NCM622 cathode electrode sheet, under a heat source temperature of 363 K, the roller speed should not exceed 10 m/min. Increasing the heat source temperature significantly accelerates the heating rate: at a roller speed of 15 m/min, for every 5 K increase in heat source temperature, the temperature at the coating‐current collector interface region rises by approximately 4 K. During the hot rolling process, electrode sheet with different material ratios exhibit no significant differences in temperature variation.

Study of the combustion behavior of wheat straw using TG–DSC under multiple heating rates

Abstract Achieving a reliable strength–toughness synergy in medium-carbon steels is crucial for lightweight and safety-critical components. Here, we compare a rapidheating route (RH) with a conventional furnace route (CH) to clarify how heating rate governs toughness in a Fe-0.3C-0.9Mn-0.8Si steel. Microstructural features were quantified by SEM and EBSD, and mechanical responses were evaluated through tensile testing, sub-zero Charpy impact, and J-based fracture toughness measurements. Despite nearly identical strength levels, RH steel exhibits a pronounced increase in both impact energy and fracture resistance. The improvement is associated with (i) a small fraction of ferrite retained after rapid austenitization, which introduces mechanical heterogeneity, and (ii) refined martensitic packets/grains accompanied by a higher population of high-angle boundaries. These microstructural changes jointly promote crack-tip plasticity, enhance crack deflection, and slow down crack advance. The present results highlight rapid heating as a viable, energy-efficient pathway to produce high-strength steels with superior toughness.

ABSTRACT The off‐centered stagnation point flow (S‐PF) phenomenon is important in many technical domains where flow patterns affect efficiency and performance. In these systems, the interplay between asymmetric flow and disk rotation influences the temperature boundary layer and concentration gradients, either augmenting or impeding heat and mass transfer rates. Earliest studies focused on stagnation flows or considered only a few thermal or chemical effects, leaving the combined influence of off‐centered asymmetry. Hence, this work fills that gap by examining the significance of thermophoretic particle deposition on the off‐centered S‐PF of fluid via a rotating disk subjected to activation energy. Moreover, the artificial neural network is used to estimate the heat transmission rate as a function of various factors. Increased magnetic field and permeability parameters decrease the momentum field. The concentration profile decreases as the thermophoretic coefficient increases.

ABSTRACT This study investigates the thermal curing behavior of allyl‐functionalized SMP‐10, a preceramic polymer used as a silicon carbide (SiC) precursor in ceramic matrix composites (CMCs). The relatively high curing temperature of SMP‐10 may pose a significant processing challenge, as it can impact quality, microstructure, and performance of the composite. However, the allyl group enables radical‐initiated crosslinking pathways. To address this, the effect of radical initiators, dicumyl peroxide (DCP) and Luperox 101, on lowering the curing temperature was examined. Using non‐isothermal differential scanning calorimetry (DSC) at heating rates of 0.5, 1, 2.5, 5, and 10/min, the behavior of pure SMP‐10 and systems with 2 wt.% initiator was monitored. Kinetic analysis was performed using Kissinger and Ozawa peak‐based methods, model‐free isoconversional methods (Kissinger–Akahira–Sunose [KAS], Flynn–Wall–Ozawa [FWO], and Starink) and model fitting method (Master plot). The results showed that the initiators significantly lower the onset curing temperature. However, the apparent activation energy () increases from approximately 116–122 kJ/mol for pure SMP‐10 to 141–153 kJ/mol for the system with DCP and 155–156 kJ/mol for the system with Luperox 101. To better understand this trend, transition state theory was applied. It was found that the acceleration is not driven by a reduction in the enthalpic barrier, but rather by a shift in the entropy of activation (), from negative values in the pure system (approximately J/) to large positive values with initiators (approximately 77 J/ for DCP and 85 J/ for Luperox). The results suggest that curing in the presence of initiators proceeds through a dissociative transition state that is entropically more favorable, leading to a lower Gibbs free energy of activation (). These findings provide a basis for developing more efficient low‐temperature curing strategies for advanced CMC processing.

Aluminum–silicon (AlSi) coatings on steel substrates provide corrosion and scaling protection in hot forming, but their high reflectivity limits efficient radiative heat transfer during furnace heating. Although diffusion annealing, anodizing, or additional absorption coatings have been proposed to increase absorptivity, a simple alkaline surface treatment has not been explored in this context. This study investigates the effect of controlled alkaline pickling on AlSi‐coated 22MnB5 blanks. Microstructural, optical, and thermal properties are systematically analyzed. Selective dissolution of Al‐rich phases exposes Si‐rich structures, raising the absorption coefficient at a reference temperature of 950°C from 0.23 (untreated) to 0.50. Heating rates increase accordingly from 6.0 to 11.3 K s –1 , representing an improvement of up to 88%. Absorption coefficients and heating rates exhibit a strong linear correlation. An optimal process window (1.8–5.0 g m –2 specific mass loss) yields 40%–50% faster heating rates to reach 900°C. Overall, the results demonstrate that rapid alkaline surface modification provides a straightforward approach to significantly enhance furnace efficiency in hot forming. It also offers a promising pathway for energy reduction in automotive manufacturing.

Abstract Hot and tenuous plasmas have velocity distribution functions (VDFs) significantly different from Maxwellian distributions. Characterizing how these differences impact wave damping and emission necessitates sophisticated methods for determining the associated dielectric plasma response. The Arbitrary Linear Plasma Solver ( ALPS ) is a tool for calculating such responses through numerical integration of arbitrary gyrotropic VDFs, rather than using analytical models, for example bi‐Maxwellians, for the VDF. We consider dispersion relations for beam‐driven instabilities, proton‐cyclotron waves, and kinetic Alfven waves, derived using example VDFs from Parker Solar Probe/SPANi measurements during Encounters 22 and 23. The same kinds of waves are supported, but non‐Maxwellian structures drive significant changes in the amount of energy absorbed by the charged particles or released into the waves, altering expected heating rates from these waves in the inner heliosphere.

We study the impact of an unshielded dielectric-here, a bare optical fiber-on a ^{40}Ca^{+} ion held several hundred microns away in a cryogenic surface electrode trap. We observe distance-dependent stray electric fields of up to a few kV/m due to the dielectric, which drift on average less than 10% per month and can be fully compensated with reasonable voltages on the trap electrodes. We observe ion motional heating rates attributable to the dielectric of ≈30 quanta per second at an ion-fiber distance of 215(4) μm and ≈1.5 MHz motional frequency. These results demonstrate the viability of using unshielded, trap-integrated dielectric objects such as miniature optical cavities or other optical elements in cryogenic surface electrode ion traps.

Time-dependent drives hold promise for realizing non-equilibrium many-body phenomena that are absent in undriven systems1-3. Yet, drive-induced heating normally destabilizes the systems4,5, which can be parametrically suppressed in the high-frequency regime by using periodic (Floquet) drives6,7. It remains largely unknown to what extent highly controllable quantum simulators can suppress heating in non-periodically driven systems. Here, using the 78-qubit superconducting quantum processor, Chuang-tzu 2.0, we report the experimental observation of long-lived prethermal phases in many-body systems with tunable heating rates, driven by structured random protocols, characterized by n-multipolar temporal correlations. By measuring both the particle imbalance and subsystem entanglement entropy, we monitor the entire heating process over 1,000 driving cycles and observe the existence of the prethermal plateau. The prethermal lifetime is 'doubly tunable': one way by driving frequency, the other way by multipolar order; it grows algebraically with the frequency with the universal scaling exponent 2n+1. Using quantum-state tomography on different subsystems, we demonstrate a non-uniform spatial entanglement distribution and observe a crossover from area-law to volume-law entanglement scaling. With 78 qubits and 137 couplers in a two-dimensional configuration, the entire far-from-equilibrium heating dynamics are beyond the reach of simulation using tensor-network numerical techniques. Our work highlights superconducting quantum processors as a powerful platform for exploring universal scaling laws and non-equilibrium phases of matter in driven systems in regimes where classical simulation faces formidable challenges.

Abstract Trapped ions in micro-cavities constitute a key platform for advancing quantum information processing and quantum networking. By providing an efficient light-matter interface within a compact architecture, they serve as highly efficient quantum nodes with strong potential for scalable quantum network. However, in such systems, ion trapping stability is often compromised by surface charging effects, and nearby dielectric materials are known to cause a dramatic increase in the ion heating rate by several orders of magnitude. These challenges significantly hinder the practical implementation of ion trap systems integrated with micro-cavities. To overcome these limitations, we present the design and fabrication of metal-shielded micro-cavity mirrors, enabling the stable realization of ion trap systems integrated with micro cavities. Using this method, we constructed a needle ion trap integrated with fiber Fabry-Pérot cavity and successfully achieved stable trapping of a single ion within the cavity. The measured ion heating rate was reduced by more than an order of magnitude compared with unshielded configurations. This work establishes a key technique toward fully integrated ion-photon interfaces for scalable quantum networks.

Existing coal spontaneous combustion liability assessments suffer from incomplete temperature range coverage, poor cross-rank comparability, and weak correlations between microscopic essence and macroscopic criteria—issues that undermine reliability and risk coal mine safety. This study aims to establish a structure-driven intrinsic identification system to address these gaps. Using 10 cross-rank coal samples (lignite, bituminous coal, and anthracite), we conducted systematic research via experiments, model building, and theoretical verification. We integrated three stage-specific parameters (each matching a combustion phase): saturated oxygen uptake (VO2, 30 °C chromatographic adsorption), average heating rate R70 (40–70 °C adiabatic oxidation), and Fuel Combustion Characteristic index (FCC, 110–230 °C crossing point method). With Information Entropy weighting (VO2: 0.296; R70: 0.292; and FCC: 0.412), we constructed the Multi-Factor Comprehensive Spontaneous Combustion Index (MF-CSCI). We also screened functional groups via FTIR, built a microstructure-driven model (MD-CSEI, linking groups to MF-CSCI), and verified mechanisms via DFT. Results show MF-CSCI covers the full “adsorption-heat accumulation-self-heating” process: HG lignite (MF-CSCI = 1.0) had high liability and YCW anthracite (MF-CSCI = 7.98) had low liability, solving cross-rank issues. Pearson analysis found –OH positively correlated with MF-CSCI (r ≈ −0.997), C=C negatively (r ≈ −0.951); MD-CSEI achieved R2 = 0.863 (p = 0.042). This study improves cross-rank assessment accuracy, enables rapid micro-to-macro risk prediction, and provides a theoretical basis for on-site coal safety management.

ABSTRACT Recycled carbon fibers (rCFs), typically recovered in short and randomly oriented forms, are often limited to downgraded applications with reduced commercial value. Here, we demonstrate their effective upcycling into shape memory polymers (SMPs) with enhanced multifunctional performance. SMP composites containing rCFs of varying lengths (0.5 and 4 mm) and loadings (0–3 wt.%) were systematically investigated under tensile test, thermal radiation, hot‐water, and electro‐activation. rCFs significantly improved mechanical properties, with 4 mm fibers yielding the highest strength and modulus. At 2 wt.% loading, rCFs accelerated heating to T g (≈52°C) from 0.15°C/s to 0.52°C/s, reducing full‐recovery time from ~240 to ~100 s. Increasing the loading to 3 wt.% yielded a more uniform temperature distribution, albeit with a slightly reduced heating rate (0.45°C/s). Hot‐water activation enabled complete recovery within 10 s for all samples, whereas electro‐activation exhibited a pronounced length effect, such that only 4 mm rCFs formed conductive networks enabling full recovery within 20 s. These findings establish a sustainable strategy for transforming rCFs into high‐value, multi‐responsive SMP actuators, highlighting their potential in advanced smart materials and sustainable manufacturing.

The presence of caged dynamics, the Johari-Goldstein (JGβ) relaxation preceding the cooperative α-relaxation, and the fact that their properties are interconnected have been established universally for glass-forming liquids of various kinds [K. L. Ngai, Prog. Mater. Sci. 139, 101130 (2023)]. We apply the universal properties of the three processes in interpreting or reinterpreting the calorimetric and dielectric relaxation data of four amorphous waters: amorphous solid water (ASW), hyperquenched glassy water (HGW), low-density liquid water (LDL), and high-density liquid water (HDL). The presence of the JGβ relaxation and the caged dynamics before the terminal α-relaxation, and the interrelations between their respective properties, are found in the four amorphous waters exactly as in other glass-formers. The existence of the JGβ glass transition temperature, Tgβ, is found indirectly from the response of the caged dynamics in ASW, HGW, and HDL, and its value of ∼113K is consistent with the extrapolation of the dielectric JGβ relaxation times τβ(T) to long times. The calorimetric data of LDL at a heating rate of 10 K/min show Tgα of LDL is 136K, which is the same as that of ASW and HGW incidentally. The calorimetric and dielectric data of HDL at temperatures below 125K, before it transforms to LDL at higher temperatures, are interpreted as originating from the JGβ relaxation and not from the α-relaxation. The value of Tgβ of HDL obtained from calorimetry or deduced from the dielectric JGβ relaxation times τβ(T) is also near 113K. The α-relaxation glass transition temperature Tgα of HDL, obtained by extrapolating the values from calorimetric and volumetric studies at elevated pressure to ambient pressure, are 137 and 128K respectively. The 137K for Tgα is supported by observation of glass transition at the same temperature by DSC in samples of HDL prepared by compressing droplets of HGW. Assuming τα(Tgα) is 100s, the value of the calorimetric Tgα for HDL is close to the calorimetric and dielectric τα(T) of HGW. The τα(T) of HGW and LDL have Arrhenius temperature dependence with a small fragility index m. The Arrhenius temperature dependence of τβ(T) for HGW, HDL, and LDL are similar as well. Applying the relation between τα(T) and τβ(T) from the Coupling Model, the averaged coupling parameter nav ∼ 0.18 is deduced for all four amorphous waters. Such a small value of nav is consistent with the frequency dependence, ∼ν-nav, on the high-frequency flank of the α-loss peak of HGW and LDL Thus, the small nav correlates with the small m, in accord with the correlation found in other glass-formers.

Abstract The 2024 April 8 total solar eclipse provides a unique opportunity to study the solar corona. This work presents our simulations of the solar corona at the time of the eclipse based on magnetohydrodynamic modeling performed with the Alfvén Wave Solar atmosphere Model in the Space Weather Modeling Framework, developed at the University of Michigan. We performed multiple simulations based on photospheric magnetic maps from four sources, i.e., ADAPT-GONG, Lockheed Martin ESFAM-HMI, HipFT-HMI, and NSO-NRT-HMI maps. Our study focuses on how differences in the magnetic field maps affect the coronal magnetic field structure and coronal heating properties in the simulation. The synthesized observables show remarkable differences due to the distinct magnetic coronal topologies, which stem from the different local magnetic flux distributions. We analyze the properties of the open magnetic flux regions of the models. We also study the coronal heating rate in the models. The total volume integrated heating rate yields a difference of 20% across the models. The results also show that the differential emission measure in the high-temperature regions is sensitive to the magnetic field maps. Our findings underscore the importance of comprehensive photospheric magnetic field data in improving future solar coronal models.

Abstract The grain coarsening behavior of a powder metallurgy polycrystalline γ – γ′ nickel-based superalloy under γ '-supersolvus solution heat treatment (SHT) was studied. Various samples were extracted from isothermally forged turbine disks and submitted to SHTs in a laboratory furnace. γ grain evolution take place quickly during the heating step to the solution temperature and is most likely governed by static recrystallization, where the final grain size distribution is defined by the density of recrystallized grain nuclei whose boundaries migrate to consume the residual work hardened grains in the microstructure. Microstructure with limited work hardening ( i.e., determined as having a 0.16 and 0.38 deg grain-surface averaged grain averaged misorientation and grain orientation spread respectively) can form heterogenous grain structures composed of some grains of much larger size than their neighbors (> 200 µ m), which decreases the material’s fatigue resistance. Once the residual work hardening is consumed, the grain structure shortly remains stable due to the pinning pressure exerted by nanometric (Hf, Zr)O 2 oxide and (Nb, Ti)C carbide particles on grain boundaries. On slightly work-hardened sample material, a slower heating rate to the solution temperature increases the propensity to form grains of excessive size (> 200 µ m) and rather heterogeneous grain size distribution. Additional interrupted SHTs, microstructural investigations and rough calculations of the driving pressures exerted on the grain boundaries illustrated that such a phenomenon could be favored by several concomitant factors during the 2 °C/min temperature ramp up to the SHT temperature, such as ripening of the γ ′ precipitates population during their dissolution, limited statically recrystallized nuclei and exposure to a slightly positive grain boundary driving pressure balance over a prolonged period of time.

Abstract The escalating accumulation of hospital plastic waste, primarily composed of polypropylene and polyethylene, poses a pressing environmental challenge due to the widespread use of disposable medical items and inadequate waste management practices. This study explores the thermochemical valorization of selectively decontaminated hospital plastic waste via batch pyrolysis conducted at 400°C–500°C under an inert nitrogen atmosphere. Optimal pyrolysis conditions 475°C, 20°C/min heating rate, and 45-minute retention time yielded a maximum of 62 wt% pyrolytic oil. Gas chromatography–mass spectrometry revealed that the oil’s composition predominantly comprises C₁₂-C₂₂ linear aliphatic hydrocarbons, indicating its suitability as a diesel-range blendstock. The oil had a calorific value of 41.2 MJ/kg, a viscosity of 3.6 cSt, and a density of 845 kg/m3. By-products included syngas (18 wt%) with a lower heating value of 16 MJ/m3 and char (20 wt%) with 52% fixed carbon, ensuring comprehensive energy recovery. Fourier transform infrared spectroscopy and energy-dispersive X-ray spectroscopy detected no chlorine-containing compounds above ~0.1 wt%, suggesting effective exclusion of polyvinyl chloride. A techno-economic analysis of a 10 kg/h modular pyrolysis unit indicated an energy offset of ~50 kWh/day and a payback period of 1.5–2 years. These findings highlight the technical, economic, and environmental feasibility of deploying decentralized pyrolysis units within hospital infrastructure, thereby advancing circular-economy principles and sustainable plastic-waste management, aligned with global sustainability goals.

Purpose This study investigates the boundary-layer flow, heat transfer and mass transfer characteristics of a Casson-based hybrid nanofluid over a permeable stretching surface embedded in a porous medium. The analysis includes the effects of magnetohydrodynamics (MHD), Brownian motion, thermophoresis, thermal radiation and variable viscosity. Design/methodology/approach The hybrid nanofluid, composed of aluminum and silver nanoparticles suspended in a Casson base fluid, was modeled using a non-Newtonian rheological framework. The governing partial differential equations were transformed into a system of coupled, nonlinear ordinary differential equations via similarity transformations. This system was solved numerically using a fourth-order Runge–Kutta method combined with a shooting technique. Findings An increase in the Casson parameter enhances resistance to shear, thereby reducing the velocity profile. The Brownian motion (Nb) and thermophoresis (Nt) parameters significantly augment the thermal and concentration boundary layers, increasing wall heat and mass transfer rates by approximately 10–20% over baseline values. The magnetic parameter (M) reduces fluid velocity due to the Lorentz force but increases the temperature gradient at the wall, resulting in a steeper thermal boundary layer. A higher permeability parameter (K1) enhances thermal dispersion while simultaneously suppressing flow speed. An increase in the Prandtl number thins the thermal boundary layer, whereas an increase in the Schmidt number compresses the solutal boundary layer; both trends align with classical transport theory. The combined influence of these parameters reveals complex, nonlinear interactions within the system. Originality/value This study underscores the importance of multiphysics modeling in hybrid nanofluid systems. The extended insights provided can serve as a foundation for designing and optimizing microfluidic heat exchangers, MHD pumps, energy storage units and biomedical devices that utilize advanced nanofluidic flows.

Purpose This study aims to numerically investigate the double-diffusive convection of a Casson ternary hybrid nanofluid (Al2O3–CuO–Ag/fluid) within a concentric annulus featuring an inner polygonal cylinder. The purpose is to quantify the impact of fluid rheology (Casson parameter) and geometry (circular, triangular, square inner cylinder) on heat and mass transfer rates, providing insights for the design and optimization of advanced thermal management systems. Design/methodology/approach The governing nonlinear partial differential equations are solved using a Galerkin finite element method. The implementation uses a Newton–Raphson iterative scheme to handle the system’s nonlinearity. The analysis is conducted for a range of key parameters, and the results are validated against established benchmark studies to ensure numerical accuracy and reliability. Findings Increasing the Casson parameter (γ) from 0.1 to 10 significantly enhances transport rates, boosting the average Nusselt number by 20.1% (circular), 32.4% (triangular) and 30.0% (square). The average Sherwood number sees even greater enhancement, rising by 137.0%, 154.0% and 158.0%, respectively. The circular inner cylinder geometry consistently outperforms the polygonal shapes, achieving superior heat and mass transfer due to its streamlined geometry which minimizes flow obstruction. Originality/value This work provides a novel analysis of double-diffusive convection for a Casson ternary hybrid nanofluid in a complex annular geometry with inner polygonal cylinders. The combined investigation of non-Newtonian rheology, multi-component nanoparticles and geometric effects on both thermal and solutal transport represents a significant extension of existing literature, offering new quantitative insights for system optimization.