A comprehensive characterization of tender coconut waste biochar produced through slow pyrolysis at different temperatures and heating rates

Agricultural HDPE pyrolysis for environmental management: Feedstock complexity, reaction dynamics, and circular resource recovery.

Thermal simulation and kinetic modeling of medium–low maturity shale source rock: Influence of pressure and heating rate on hydrocarbon generation

Biostimulation of stacked microbial fuel cells assisted biodrying added with biochar and Fe3O4: comparative analysis from biodrying performance to microbial community.

Hydrocolloid mediated reconstruction and functionality of tapioca starch-yeast protein emulsion-filled gels: Toward β-carotene delivery and dysphagia-friendly foods of 3D printing.

The influence of coal pyrolysis heating rate on char fragmentation propensity during secondary reactions

Recent studies have aimed to develop sustainable bio-based fire-resistant building materials to replace the conventional building materials. Traditional fire retardants such as halogenated compounds rely on toxic chemicals that pose environmental and health risks. Mycelium-Based Composites (MBCs), produced from fungal mycelia cultured from agricultural byproducts, offer a promising eco-friendly alternative with inherent fire-retardant properties. Addressing fire safety in buildings is vital for enhancing resilience, reducing casualties and economic losses, and aligning buildings with development goals. MBCs contribute to circular economies by repurposing waste and making it key to climate-adaptive construction. This study provides a review of MBCs' fire-retardant properties from various studies. The high char formation of MBCs (up to 48% at 600°C) at low heating rates (as low as 33 kW/m²), delayed ignition, and minimal smoke production outperformed those of their synthetic counterparts. This study identifies key research gaps and provides actionable solutions, such as tripartite studies, to disentangle mycelium, substrate, and additive effects.

Phase transformation of α-sheet borophene under thermal stimuli: molecular dynamics study of atomic mechanisms and heating rate effects

A novel strategy for arsenic management in paddy fields: Trapping arsenic via electrochemical oxidation and adsorption on biochar electrodes.

Valorization of olive stone waste-derived biochar for the continuous fixed-bed removal of Cr(VI), Pb(II), and Cd(II) from wastewater.

Glycidyl azide polymer (GAP)-based polyurethane, a kind of energetic thermoplastic elastomer (ETPE), is a promising binder for advanced solid propellants, but its thermal decomposition involves overlapping competitive reactions that conventional single-step kinetic models cannot characterize accurately, limiting its engineering applications. To address this limitation, a constrained asymmetric Gaussian deconvolution strategy with fixed peak area ratios and shape constraints was developed in this work. This strategy was applied to resolve overlapping reaction rate curves converted from derivative thermogravimetric data of GAP-based ETPEs with 50 wt% GAP content at four heating rates of 5, 10, 15 and 20 K·min-1. The complex decomposition process was successfully split into five stages, assigned to azide cleavage, polyether backbone scission, carbamate cleavage, hydrocarbon product degradation and residue decomposition, with a goodness of fit of R2 > 0.998. Apparent activation energies of the five stages were determined through cross-validation by the Friedman and Flynn-Wall-Ozawa methods without prior assumption of reaction mechanisms, following the order of residue decomposition (181.4 ± 1.0 kJ·mol-1) > hydrocarbon product degradation (159.9 ± 1.0 kJ·mol-1) ≈ azide cleavage (156.5 ± 0.6 kJ·mol-1) > backbone scission (135.1 ± 0.7 kJ·mol-1) > carbamate cleavage (111.9 ± 1.1 kJ·mol-1). Pre-exponential factors with lnA0 values ranging from 22.2 to 34.0 were derived via the kinetic compensation effect. Finally, generalized master plots were employed to compare with classic solid-state reaction models for mechanistic insight, and the Šesták-Berggren model fit three major stages excellently (R2 > 0.996) by accounting for synergistic nucleation-growth and phase boundary mechanisms, enabling high-precision kinetic equations. It should be noted that the constrained deconvolution method proposed in this work has general applicability for kinetic analysis of GAP-based ETPEs with different formulations and other complex energetic polymer systems, while the obtained kinetic parameters are composition-specific and only applicable to the corresponding ETPE formulation studied herein.

ABSTRACT High-pressure DSC was employed to investigate the thermal decomposition of 2,4-dinitro-2,4-diazapentane (DNDA5), showing that pressurization shifts the main exothermic process to higher temperatures. Multi-rate kinetic analyses using peak-based and model-free isoconversional methods give a mean activation energy of 212 kJ·mol−1 over α = 0.1–0.8 and a pre-exponential factor of 2.8 × 1019 s−1. Gaussian calculations coupled with condensed-phase FT-IR suggest that decomposition is initiated by C–H bond scission. The heat of combustion and isobaric heat capacity were determined by oxygen-bomb calorimetry and C80 microcalorimetry, and a near-ambient Cp–T correlation was fitted for screening-level thermal-safety assessment. Using these thermokinetic and thermophysical data, TSADT and Tb were evaluated as 213.68°C and 227.51°C, respectively, with an adiabatic time-to-explosion of 112.3 s. DSC compatibility screening further indicates that DNDA5 is compatible with NC, NQ, and RDX at a 1:1 mass ratio (|ΔTp|<4°C). The interval method bounds the surface characteristic temperature between the exothermic onset at the lowest heating rate and the main-peak temperature, indicating a high-Zel’dovich-number, condensed-phase-controlled regime. Overall, DNDA5 exhibits favorable thermal stability and shows potential as an energetic plasticizer for gun propellants.

Enhancing the heat and mass transfer performance of working fluids remains a critical challenge to pursue sustainable and energy-efficient technologies. Although regular working fluids have superior thermo-physical properties to pure base fluids, they often face limitations that hinder their adoption in multifunctional applications. To overcome these challenges, this study develops a novel, comprehensive and physically consistent mathematical model for an unsteady, electrically conducting ternary hybrid nanofluid composed of graphene oxide (GO), cerium oxide (CeO[Formula: see text], and hexagonal boron nitride ([Formula: see text]-BN) suspended in an environmentally friendly ionic liquid (Ethyl-3-methylimidazolium tetrafluoroborate) [EMIM][BF 4 ]. The model integrates magnetic effects, radiation heat transfer, viscous dissipation, Joule heating, and coupled thermo-diffusion effects. A fractal–fractional derivative operator is employed to generalize the governing equations, while the local radial basis functions (RBF) scheme is used to solve them numerically. Computational and graphical results reveal that CeO 2 suppresses the fluid velocity due to increased inertial resistance, while the dispersion of [Formula: see text]-BN significantly enhanced the thermal profile, resulting in a higher Nusselt number. Furthermore, higher values of Dufour and Soret numbers enhance the coupled heat and mass transfer rates, indicating the model’s potential to design advanced heat exchangers and smart cooling devices. These findings provide valuable guidelines for designing compact heat exchangers and thermal energy storage systems for applications in renewable energy and microelectronics cooling.

This study investigates the critical transformation temperatures of a high-strength API-grade steel through thermal analysis and software simulations; the precise determination of these temperatures is essential for enhancing the efficacy of subsequent experimental trials. Utilizing the ‘Quench Properties’ module of JMatPro® V14, characteristic transformations were identified between 950 °C and 25 °C under stable conditions. Heating rates of 5, 10, and 30 °C/s were applied to determine critical temperatures, with Ac1 ranging from 700 °C to 750 °C and Ac3 from 850 °C to 900 °C. Niobium content may influence Ac1 and Ac3, promoting the ferritic phase and elevating transformation temperatures at a heating rate of 30 °C/s. Conversely, a rate of 10 °C/s significantly influenced austenite formation, impacting the development of microconstituents that enhance both strength and elongation post-quenching. Furthermore, slow cooling was found to favor the premature formation of allotriomorphic ferrite, which hinders the transformation of austenite into bainite and martensite during accelerated cooling. Finally, this study corroborates that JMatPro® is a reliable tool for predicting critical temperatures and designing optimized thermomechanical processing routes.

Abstract The growing demand for efficient energy storage systems in applications such as electric vehicles, smart grids, and portable electronics has intensified interest in high-performance lithium–metal batteries. Conventional fabrication routes for porous copper current collectors (CCs) face limitations in achieving complex architectures and reliable mechanical stability. In this work, stereolithography-based 3D printing combined with pressureless sintering is employed for the rapid fabrication of copper CCs. For the first time, porous copper CCs are fabricated using this approach, delivering controlled architectures with enhanced structural robustness and electrochemical functionality. Optimization of sintering parameters, including sintering temperature, heating rate, and holding time, was carried out using Response Surface Methodology based on a Box–Behnken design, followed by multi-objective genetic algorithm analysis in MATLAB. The optimized conditions significantly improved relative density, compressive yield strength, and volumetric shrinkage, while minimizing experimental effort. The fabricated porous copper CC exhibited superior mechanical strength under compression, withstanding ~ 35 MPa at 60% strain, ensuring integrity during coin cell assembly and cycling. Electrochemical testing demonstrated a stable and high Coulombic efficiency of approximately 95 percent over 100 cycles, significantly outperforming conventional copper foil. The porous structure effectively facilitated uniform lithium deposition, mitigated dendrite growth, and accommodated volume fluctuations. This research offers a scalable route to fabricate durable, high-performance CCs, advancing next-generation electrochemical systems with stable, high-surface-area electrodes. Graphical Abstract

In this study, the feasibility of electrospraying as an alternative processing technique for the preparation of composite solid rocket propellants (SRPs) was investigated. The main objective was to improve microstructural homogeneity and interfacial contact between the oxidizer, energetic additive, and metallic fuel without altering the chemical composition of the formulation. Additionally, porous electrosprayed SRP formulations were prepared to examine the influence of controlled porosity on thermal decomposition behavior. The prepared materials were characterized using scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM/EDS) to assess microstructural features and component distribution. Thermal decomposition behavior and kinetic parameters were evaluated using simultaneous DSC/TG analysis conducted at multiple heating rates. Safety-related properties were assessed through friction sensitivity testing, while post-decomposition solid residues were analyzed using SEM/EDS and X-ray diffraction. The results show that electrospraying improves structural homogeneity, reduces solid residue formation after thermal decomposition, and decreases apparent activation energy, while maintaining unchanged friction sensitivity. These findings demonstrate the potential of electrospraying as a physical processing route for tailoring the microstructure and thermal behavior of composite solid rocket propellants.

ABSTRACT A simple and economical strategy for preparing CeO 2 was developed via direct calcination of cerium acetate, and it was employed as a catalyst for glycerol carbonate (GC) synthesis from glycerol (GL) and CO 2 . This method requires no extra reagents, significantly simplifies the procedure, and offers low cost and short turnaround times. The effects of calcination temperature on the catalytic performance of CeO 2 were systematically investigated. The results demonstrated that calcination temperature affected the specific surface area, surface Ce valence, oxygen vacancy (Ov) content, and distribution of basic sites with varying strengths. Among these factors, the specific surface area did not significantly influence its catalytic performance, while the Ov concentration and the distribution of basic sites did affect GC synthesis. Specifically, the total basicity and Ov content primarily affected GL conversion, while the amount of medium‐strong, strong basic sites affected GC selectivity. Additionally, both the heating rate and calcination time also influenced the catalytic performance. When the calcination temperature was 700°C, heating rate was 10°C/min and the calcination time was 4 h, the CeO 2 had better catalytic performance, achieving 69.8% GL conversion and 92.4% GC selectivity.

In the core accretion scenario, forming planets start to acquire gaseous envelopes while accreting solids. Conventional 1D models assume envelopes to be static and isolated. However, recent 3D simulations demonstrate dynamic gas exchange from the envelope to the surrounding disk. This process is controlled by the balance between heating, through the accretion of solids, and cooling, which is regulated by poorly known opacities. In this work we systemically investigated a wide range of cooling and heating rates using 3D hydrodynamical simulations. We identify three distinct cooling regimes. Fast-cooling envelopes ( β ≲ 1, with β the cooling time in units of orbital time) are nearly isothermal and have inner radiative layers that are shielded from recycling flows. In contrast, slow cooling envelopes ( β ≳ 10 3 ) become fully convective. In the intermediate regime (1 ≲ β ≲ 300), envelopes are characterized by a three-layer structure, comprising an inner convective, a middle radiative, and an outer recycling layer. The development of this radiative layer traps small dust and vapor released from sublimated species. In contrast, fully convective envelopes efficiently exchange material from the inner to the outer envelope. Such fully convective envelopes are likely to emerge in the inner parts of protoplanetary disks (≲ 1 au) where cooling times are long, implying that inner-disk super-Earths may see their growth stalled and be volatile-depleted.

Thermoplastics provide several advantages over thermoset composites, including the potential for fastener-free assembly via induction welding. Key parameters in modeling this process include coil frequency, excitation current, and coil offset distance. However, optimizing heat generation through coil geometry remains underexplored. This study aims to derive relationships between coil geometry, heating rate, and frequency through an iterative coil design approach. Two coil design groups are developed to target heat generation in specific regions. Each design undergoes a numerical analysis loop to assess heating performance. Designs showing high heating rates and appropriate temperature profiles are fabricated and experimentally tested. The thermocouple temperature data from these tests are compared to numerical predictions to validate model accuracy. Results show strong agreement between simulations and experiments. The best-performing coils are then used in the induction welding of a stiffened fuselage demonstrator. Welding parameters are determined for each component in the stiffened fuselage demonstrator, and joint performance is evaluated by prying open the welded joints for inspection.

ABSTRACT Aerosol effect on orographic clouds and its feedback on the surrounding meteorological environment have been investigated using the Weather Research and Forecasting Model with the spectrum bin microphysics scheme. Analysis of aerosol impacts on water vapor mixing ratio, latent heating rates, and wind field reveals that enhanced aerosol loading invigorates convection accompanied by intensive latent heat release, which induces stronger convergence at 3–5 km of altitude and leads to increased horizontal wind speed around the periphery of clouds on the windward slope. Moreover, the enhanced negative buoyancy around the periphery of clouds under polluted condition induces the descent of dry air from the middle troposphere, together with the downslope winds, consequently resulting in lower humidity and higher temperature at lower levels of the lee side. Under clean condition, the surface temperature of the leeward slope is 6.0 K higher than that of the windward slope, while this difference is increased to 7.0 K under polluted condition. The surface relative humidity on the lee side is 42.6% and 21.6% for clean and polluted conditions, respectively. By intensifying the downslope wind and reducing leeside humidity, aerosols suppress subsequent cloud growth and thereby alter the precipitation pattern, leading to higher rain rates over the windward slope and leeward side under polluted and clean conditions, respectively.