Search Results (6,973)

Edible mushrooms (Suillus luteus) represent valuable sources of nutrients and bioactive compounds that are sensitive to drying conditions. The objective of this study was to determine the drying time, kinetic model, effective diffusivity, activation energy, and color changes in S. luteus samples subjected to convective and vacuum drying at 70 and 50 °C, respectively, following pretreatments with 1% citric acid or blahing. The shortest drying time to reach equilibrium moisture was 14 h at 70 °C under a vacuum, whereas the longest was 44 h at 50 °C under convective drying. The Midilli, logarithmic, and Henderson and Pabis models provided the best fits for vacuum drying. The effective moisture diffusivity values ranged from 5.83 × 10⁻⁹ m²s⁻¹ at 50 °C to 1.159 × 10⁻⁸ m²s⁻¹ at 70 °C, while the mean activation energies for vacuum and convective drying were 10.27 kJmol⁻¹ and 24.7 kJmol⁻¹, respectively. The highest rehydration capacity was observed in untreated samples dried under a vacuum, with a value of 3.5 g H₂O/g dry matter, whereas convective drying yielded 2.4 g H₂O/g dry matter. The greatest shrinkage with respect to thickness was observed in those treated with citric acid and blanching. Correlation analysis of color revealed a strong negative relationship between lightness (L*) and total color difference (ΔE), as well as high positive correlations among a*, b*, and C*, suggesting that color transformations occur jointly throughout dehydration. The findings indicate that effective diffusivity increased with temperature, untreated samples exhibited greater water loss, and rehydration ratios were higher in untreated compared with pretreated samples. Full article

With increasingly stringent greenhouse gas emission regulations, carbon emissions from marine engines have become a major concern, driving the shipping industry to actively explore efficient and clean alternative fuels. Among the various candidates, ammonia has attracted considerable attention in recent years due to its carbon-free nature and potential as a high-quality clean fuel. However, its practical application in marine engines is constrained by several inherent drawbacks, including a high auto-ignition temperature, low flame propagation speed, and low calorific value. Blending ammonia with natural gas has been demonstrated as an effective strategy to enhance its ignition performance. In this study, the ignition characteristics of NH₃/C1–C4 alkane mixed fuels were systematically investigated using numerical simulations. Rate of production (ROP) analysis, reaction pathway analysis, and other kinetic evaluation methods were employed to elucidate the underlying ignition mechanisms. The results reveal that blending NH₃ with C1–C4 alkanes significantly shortens the ignition delay time. When X_CH ≥ 30%, at high initial temperatures, the ignition-promoting effect is most pronounced for NH₃/C₂H₆ mixtures. In contrast, under low temperature conditions, ignition performance progressively improves with increasing carbon chain length of the blended alkane fuel. The ignition delay time across different operating conditions is primarily governed by highly reactive radicals, including O, H, and OH. Elevating the initial temperature, pressure, and blending ratio promotes the earlier formation of these key radicals and increases their production rates. ROP analysis of OH radicals indicates that reaction R10 (O₂ + H ⇌ OH + O) contributes most significantly to OH generation. Furthermore, reaction pathway analysis of NH₃ shows that at lower initial temperatures, NH₃ dehydrogenation is dominated by reactions with OH radicals. At higher temperatures, a greater fraction of NH₃ participates in NO reduction reactions, thereby decreasing the proportion of NH₃ involved in dehydrogenation pathways. Full article

Optimizing stirring methods is crucial for enhancing the efficiency of the Electric Arc Furnace (EAF) production process. This study explores the mixing characteristics of a 150-ton Consteel EAF. The similarity ratio between the water model and the prototype is 1:8. The average mixing time (AMT) was employed as the criterion to evaluate various stirring methods, including the horizontal deflection angle of side-blowing, non-uniform bottom-blowing layouts, and their combinations. A new ice whose composition was a 35 wt% sugar solution was used to simulate the movement and bonding of scrap steel. The melting and temperature difference were compared in this way. The conclusions are as follows: (1) The side blowing lances with a certain angle of horizontal deflection are more conducive to the mixing of the molten pool. The preferred side-blowing lances’ horizontal deflection angle is 10°. (2) The preferred bottom blowing layout is EKO. The bottom blowing layout needs to pay attention to the offset between the bottom blowing nozzles. Bottom blowing nozzles cannot be too far or too close. Rational non-uniform layout of bottom blowing is better than uniform. (3) The preferred combined stirring layout is the EKN, combined with side blowing, with counterclockwise deflection of 10° in the horizontal direction. Gas injection of side blowing and bottom blowing exhibits complementary action zones, thereby achieving enhanced stirring uniformity in the molten bath. But it is necessary to consider the bottom-blowing and side-blowing positions to avoid the local kinetic energy loss caused by airflow offset. At the same time, the deflection angle of the side-blowing lances should be consistent with the direction of the circulation formed by the non-uniform bottom blowing. (4) Under the rational combined stirring method, the scrap steel moved faster, and the bonding phenomenon was significantly reduced. And the temperature difference decreased the fastest. In summary, the rational combined stirring method is the most preferred method for mixing. Full article

High-energy Ni-rich layered cathodes are critical for next-generation lithium-ion batteries yet remain limited by severe interfacial degradation and thermal vulnerability under high-voltage operation. In this work, a robust spinel-layered heterostructure is constructed by encapsulating LiNi₀.₈Co₀.₁Mn₀.₁O₂ (NCM811) with a LiNi₀.₅Mn₁.₅O₄ (LNMO) spinel shell via a scalable sol–gel route. Structural characterizations confirm that the coating maintains the secondary-particle architecture, while X-ray photoelectron spectroscopy reveals a chemically reconditioned interface, achieved by the scavenging residual lithium species and suppressing of rock-salt-like surface reconstruction. Consequently, the optimized 4 wt% LNMO@NCM811 electrode demonstrates significantly enhanced high-voltage (2.8–4.4 V) stability, maintaining 41.84% of its initial capacity after 200 cycles compared to only 15.75% for the pristine sample. Crucially, thermogravimetric-differential scanning calorimetry (TG-DSC) uncovers the kinetic origin of this safety improvement: the spinel shell alters the thermal decomposition pathway, delaying the 10% mass loss temperature (T_10%) from 515.2 °C to 716.6 °C and suppressing the total exothermic heat release from 208.3 J g⁻¹ to 81.5 J g⁻¹. Collectively, these results demonstrate that the co-free spinel encapsulation is a dual-functional strategy to simultaneously stabilize surficial chemistry and intrinsically enhance the thermal safety of Ni-rich cathodes for carbon-neutral energy storage applications. Full article

Amid global energy crises and environmental pollution, the valorization of renewable biomass resources like corn stover lignin is crucial. This review systematically examines the innovative application of switchable solvents (CO₂-responsive, thermo-responsive, pH-responsive) for extracting lignin from corn stover and its subsequent pyrolysis into bio-oil. We critically analyze the extraction mechanisms, key process parameters (e.g., solvent type, temperature, solid-to-liquid ratio), and their intricate effects on lignin yield and purity. Furthermore, we delve into the pyrolysis kinetics, product distribution influenced by conditions (temperature, atmosphere, catalysts), and comprehensive characterization of the resulting bio-oil. This review highlights the broad application prospects of pyrolysis oil in energy, chemical feedstocks, and niche markets, while frankly addressing current challenges: high costs, product quality issues, and technological immaturity. Finally, we propose future directions focusing on green solvent design, process intensification, multi-technique characterization protocols, and the imperative for integrated lifecycle and techno-economic assessments to guide sustainable industrialization. Full article

To advance the engineering application of the fusion decoupling combustion technology previously proposed by our research group, this work focuses on its second stage—the high-temperature syngas combustion stage—and specifically addresses the critical issue of whether high-temperature gasified syngas can achieve direct and stable ignition when mixed with ambient air. For this purpose, a high-temperature syngas combustion experimental system was established, utilizing syngas that simulates the composition of biomass gasification products as the research subject. A systematic investigation was carried out to explore the influence patterns of syngas temperature and key components on the ignition limits, which are characterized by the lower and upper limits of the excess air coefficient (λ_min and λ_max). The results indicate that increasing the syngas temperature significantly broadens the ignition limits: λ_min decreased from 0.73 to 0.59, while λ_max increased simultaneously, primarily due to accelerated reaction kinetics and the contribution of high-temperature sensible heat. An increase in H₂ content significantly expands the ignition range, whereas an increase in CO content narrows the limits, reflecting the opposing roles of these two components in terms of reactivity. Both diluent components, CO₂ and N₂, increase λ_min; however, N₂ exhibits a more pronounced inhibitory effect due to its higher volumetric heat capacity and greater thermal inertia. This study confirms the feasibility of direct ignition between high-temperature gasification syngas and ambient air, providing important experimental evidence for the engineering application of the fusion decoupling combustion process. Full article

Non-destructive testing (NDT) methods are widely used to evaluate the performance of concrete, but their accuracy can be influenced by external factors such as curing temperature. Temperature not only modifies hydration kinetics and strength development but may also change the correlation between NDT measurements and compressive strength. However, no prior research has systematically examined how different curing temperatures influence the reliability of various NDT techniques. This study evaluates three curing temperatures and their effect on the correlation between NDTs and compressive strength at various ages (1, 3, 7, 28, and 90 days). Both simple regression analysis and artificial neural networks (ANNs) were employed to predict strength from NDT measurements. Results show that NDT sensitivity to curing temperature is most pronounced at early ages, and that linear regression models cannot adequately capture the complexity of these relationships. In contrast, ANNs demonstrated superior predictive capability, though initial training with limited data led to overfitting and instability. By applying Gaussian Noise Augmentation (GNA), model accuracy and generalization improved substantially, achieving R2 values above 0.95 across training, validation, and test sets. These findings highlight the potential of non-linear models, supported by data augmentation, to improve prediction reliability, lower experimental costs, and more accurately capture the role of curing temperature in NDT–strength correlations for concrete. Full article

This study investigated heat-induced protein aggregation in skim camel milk by monitoring changes in the volume-weighted mean particle size (d_4,3) during isothermal heating (60–90 °C, up to 60 min, four temperature levels and 25 time–temperature conditions). Pronounced increases in d_4,3 with both time and temperature confirmed significant thermal aggregation. The reaction kinetics were described using a generalized exponential growth model, which fitted well at intermediate temperatures (e.g., coefficient of determination (R²) = 0.901 at 70 °C and 0.959 at 80 °C) but deviated at the lower (60 °C) and upper (90 °C) extremes, reflecting more complex behavior. Arrhenius analysis of the rate constant yielded an activation energy of 50.61 kJ mol⁻¹, lower than values typically reported for bovine milk systems, indicating that camel milk proteins require less thermal input to aggregate. In parallel, a machine learning model implemented as an artificial neural network (ANN) predicted d_4,3 from time-temperature inputs with high accuracy (R² > 0.97 across training, validation, and testing), capturing nonlinear patterns without mechanistic assumptions. Together, the kinetic and ANN approaches provide complementary insights into the heat sensitivity of camel milk proteins and offer predictive tools to support the optimization of thermal processing, formulation, and quality control in dairy applications. Full article

Polyamide 6 is an important engineering thermoplastic; however, its practical use is often constrained by its high flammability. Although aluminum diethylphosphinate is widely employed as a flame retardant for polyamide 6, its relatively slow char-forming kinetics hinders the attainment of the stringent 750 °C glow-wire ignition temperature required for electrical applications at moderate loadings. To address this limitation, a synergist was fabricated via the self-assembly of phytic acid, benzoguanamine, and ZnSO₄·7H₂O and subsequently incorporated to enhance the char-forming capability and flame retardancy of polyamide 6/aluminum diethylphosphinate composites. The results revealed that the synergist acted as an efficient charring promoter, improving flame retardancy. At a total loading of 15 wt%, the composite reached a UL-94 V-0 rating and high limiting oxygen index of 30.7%. Cone calorimetry data indicate that the peak heat release rate decreased by 34.0%, and the smoke production rate decreased by 33.3% compared with the polyamide 6/aluminum diethylphosphinate composites. Mechanistic analysis indicated that the synergist catalyzed the carbonization of the polyamide 6, enabling the formation of a dense thermally insulating char barrier in the condensed phase. Notably, the optimized formulation achieved a glow-wire ignition temperature of 750 °C, demonstrating its strong potential for high-safety electrical applications. Full article

Carbon capture and storage (CCS) is essential for achieving net-zero emissions, yet amine-based capture systems face significant challenges including high energy penalties (20–30% of power plant output) and operational costs ($50–120/tonne CO${}_2$). This study develops and validates a novel multi-scale Digital Twin (DT) framework integrating Physics-Informed Neural Networks (PINNs) to address these challenges through real-time optimization. The framework combines molecular dynamics, process simulation, computational fluid dynamics, and deep learning to enable real-time predictive control. A key innovation is the sequential training algorithm with domain decomposition, specifically designed to handle the nonlinear transport equations governing CO${}_2$ absorption with enhanced convergence properties.The algorithm achieves prediction errors below 1% for key process variables (R${}^2$> 0.98) when validated against CFD simulations across 500 test cases. Experimental validation against pilot-scale absorber data (12 m packing, 30 wt% MEA) confirms good agreement with measured profiles, including temperature (RMSE = 1.2 K), CO${}_2$ loading (RMSE = 0.015 mol/mol), and capture efficiency (RMSE = 0.6%). The trained surrogate enables computational speedups of up to four orders of magnitude, supporting real-time inference with response times below 100 ms suitable for closed-loop control. Under the conditions studied, the framework demonstrates reboiler duty reductions of 18.5% and operational cost reductions of approximately 31%. Sensitivity analysis identifies liquid-to-gas ratio and MEA concentration as the most influential parameters, with mechanistic explanations linking these to mass transfer enhancement and reaction kinetics. Techno-economic assessment indicates favorable investment metrics, though results depend on site-specific factors. The framework architecture is designed for extensibility to alternative solvent systems, with future work planned for industrial-scale validation and uncertainty quantification through Bayesian approaches. Full article

The utilization of low- and zero-carbon fuels in internal combustion engines is gaining increasing interest. In marine engine applications, the co-combustion of methane and ammonia has emerged as a promising strategy for reducing carbon emissions. In this work, a chemical kinetic mechanism for n-heptane/methane/ammonia blended fuel was developed and validated. Using this mechanism, sensitivity and chemical kinetic analyses were performed to explore the ignition characteristics of the fuel mixture. The results indicate that at an initial temperature of 1000 K, reaction R152 (C₇H_15-2 = CH₃ + C₆H₁₂) exerts the strongest inhibiting effect on ignition. C₇H_15-2 is a major low-reactivity intermediate generated during n-heptane decomposition, and the accumulation of such intermediates contributes to the negative temperature coefficient (NTC) behavior. A cross-reaction between CH₄ and NH₃, R111 (CH₄ + NH₂ = CH₃ + NH₃), was identified, which impedes the smooth progression of oxidation. Elevated temperatures, oxygen-rich conditions, and higher ammonia blending ratios promote the formation of NO. The production of N₂O is primarily governed by reaction R105 (NH + NO = N₂O + H), whose rate increases with the NH₃ molar fraction. Consumption of N₂O occurs mainly via reactions R92 (N₂O + H = N₂ + OH) and R94 (N₂O (+M) = N₂ + O (+M)), both of which occur later than its formation through R105, indicating that N₂O consumption is more sensitive to temperature. Full article

Lithium-ion batteries suffer from severe capacity fading and start-up failure at low temperatures owing to restricted Li⁺ transport and deteriorated interfacial kinetics. To enable rapid and safe activation under such conditions, this study designs a microwave-driven dual-layer leakage-proof composite phase-change module (EPG–BN–CF–PAG), comprising an epoxy–graphene–boron nitride outer encapsulation and a ceramic fiber–boron nitride porous inner scaffold that adsorbs a paraffin–graphene phase-change core. The synergy between the dense outer shell and the internal adsorption framework affords excellent shape stability, with an enthalpy retention exceeding 95% and no visible leakage after 20 heating–cooling cycles. Owing to the strong microwave-absorption capability of graphene, the module can be rapidly heated from −10 °C to ~60 °C within 60 s while establishing a homogeneous and stable temperature field. Combined simulations and experiments show that the module efficiently transfers heat to a lithium-ion cell, raising its temperature from −10 °C to ~30 °C within 60 s and thus bringing it into a practical operating window. Electrochemical impedance spectroscopy further reveals that the thermally induced activation markedly improves interfacial kinetics, reducing the bulk resistance from 500 Ω to 30 Ω and the charge-transfer resistance from 800 Ω to 30 Ω. This microwave-driven phase-change heating strategy features ultrafast response, excellent anti-leakage performance, and favorable thermal properties, providing an engineering-feasible thermal-management solution for the rapid cold start of lithium-ion batteries under extremely low-temperature conditions. Full article

Partitioning is an important characteristic of the biomass gasification process in a downdraft fixed-bed gasifier, so simulating the partition characteristics has practical guiding significance for revealing the essence of gasification reactions. In this paper, based on the real gasifier, a fluid-solid interfacial reaction method was proposed to simulate heterogeneous reactions based on a holistic gasification model. The partition characteristics, such as the boundary, position, step points, and area of zones, were explored and defined through analyzing the species concentration field, kinetic rate field of reactions, and temperature field. The results indicate that the partition characteristics of kinetic rate distributions are the root cause for zoning in fixed-bed gasification. On the center line of the fixed-bed gasifier, the change nodes of CO concentration tend to be consistent with the nodes of the high kinetic rate of reactions. These results provide a theoretical foundation for the online monitoring of and intervention in biomass gasification. Full article

Cryopreservation is a critical strategy for the long-term conservation of plant germplasm, particularly for clonally propagated crops, endangered species, and plants producing recalcitrant seeds. Hydrogel-based encapsulation systems can improve survival during ultra-low-temperature storage by providing mechanical protection, moderating dehydration, and regulating cryoprotectant uptake. Although calcium–alginate beads remain the traditional matrix for encapsulation–dehydration and encapsulation–vitrification, recent advances in biomaterials science have enabled the development of composite polysaccharide blends, protein-based matrices, synthetic polymer networks, macroporous cryogels, and functionalized hybrid hydrogels incorporating surfactants, antioxidants, or nanomaterials. These engineered systems provide improved control over water state, pore architecture, diffusion kinetics, and thermal behavior, thereby reducing cryoinjury and enhancing post-thaw recovery across diverse plant explants. This review synthesizes current knowledge on hydrogel platforms used in plant cryopreservation, with emphasis on how physicochemical properties influence dehydration dynamics, cryoprotectant transport, vitrification stability, and rewarming responses. Performance across major explant types is assessed, key limitations in existing materials and protocols are identified, and design principles for next-generation hydrogel systems are outlined. Future progress will depend on material standardization, integration with automated cryopreservation workflows, and the development of responsive hydrogel matrices capable of mitigating cryogenic stresses. Full article

The growing interest in using edible flowers as functional ingredients has increased the demand for reliable and sustainable strategies to recover and characterize their bioactive compounds. Torch ginger is a tropical species rich in anthocyanins. In this study, an ultrasound-assisted extraction (UAE) method was developed, optimized, and validated for the efficient recovery of anthocyanins from torch ginger flowers, with a clear focus on food-related applications. A Box–Behnken experimental design was applied to evaluate the influence of solvent composition, temperature, solvent-to-sample ratio, and pH on anthocyanin yield, using chromatographic responses. Solvent composition and solvent-to-sample ratio were identified as the most influential parameters, and effective extraction was achieved under mild temperature and pH conditions. The optimized conditions consisted of 84% methanol in water as the extraction solvent, a temperature of 30 °C, a solvent-to-sample ratio of 20:1 (mL g⁻¹), and a pH of 5.6. Kinetic studies revealed that a 5 min extraction time maximized recovery while preventing compound degradation. The method was successfully applied to different torch ginger varieties, revealing a strong correlation between flower color and anthocyanin concentration. This research provides a fast, reliable, and environmentally friendly approach for assessing anthocyanin content in torch ginger flowers. The results support the valorization of this edible flower as a potential source of natural colorants and bioactive ingredients, contributing to ingredient selection, quality control, and the future development of functional foods and clean-label products. Full article