Search Results (2,179)

Black rice is abundant in polyphenolic antioxidants, but conventional thermal processing degrades these heat-sensitive compounds, limiting their bioactivity. Although single-strain fermentation can improve the extraction of bioactive components, it remains challenging to simultaneously balance the flavor and bioactivity of fermented black rice products. Low-temperature co-fermentation with yeast and lactobacillus has emerged as a promising strategy to enhance both the flavor profile and functional quality of fermented foods. Therefore, this study investigates the effects of low-temperature co-fermentation with Saccharomyces cerevisiae and Lactobacillus bulgaricus 134 on the quality of black rice slurry. The efficacy was systematically evaluated by monitoring fermentation kinetics, conducting polyphenol and anthocyanin metabolomics analysis, performing flavoromics analysis, and combining in vitro ABTS radical scavenging assays with a Caco-2 cell-based oxidative stress model. The results showed that this process activated β-glucosidase within the first 24 h of fermentation. By activating terpenoid and phenolic metabolic pathways, it maximized the accumulation of anthocyanins and short-chain esters during 30–36 h, which conferred the product with prominent fruity and sweet notes. Fermented black rice slurry (FBRS) exhibited potent ABTS radical scavenging activity. In the Caco-2 oxidative stress model, FBRS pretreatment restored cellular viability, upregulated the activity of endogenous antioxidant enzymes, and reduced MDA content. This study provides a theoretical foundation for developing high-nutritional, flavor-enhanced fermented black rice products. Full article

With the continuous advancement of thrust-to-weight ratios in modern aero-engines, turbine inlet temperatures have reached levels that far exceed the thermal endurance limits of conventional superalloys and emerging ceramic matrix composites (CMCs). Consequently, thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs) have become indispensable multifunctional systems for hot-section component protection. This review systematically delineates the evolutionary trajectory of TBC/EBC systems, transitioning from traditional yttria-stabilized zirconia (YSZ) and simple silicates to advanced multi-rare-earth-doped oxides, A₂B₂O₇ pyrochlore structures, and high-entropy ceramic systems. A critical comparative assessment is provided regarding their phase stability, thermal-physical properties, and durability challenges above 1200 °C. Furthermore, this paper provides an in-depth analysis of high-temperature degradation mechanisms, focusing on the thermochemical and thermomechanical interactions under calcium-magnesium-alumino-silicate (CMAS) attack, water-oxygen corrosion, and molten salt infiltration. By synthesizing current research gaps, we highlight the trade-offs between low thermal conductivity, high toughness, and environmental resistance. Finally, a strategic roadmap for next-generation coatings is proposed, emphasizing the integration of high-entropy material design, multi-scale structural optimization, and AI-driven life prediction models to meet the stringent reliability requirements of future propulsion systems. Full article

To achieve efficient removal and defluorination of perfluorooctanoic acid (PFOA), a visualized micro-scale fused quartz tube reactor (FQTR) was constructed to systematically investigate sub/supercritical water oxidation (SCWO) processes. Under operating conditions of 200–400 °C and 8–27.3 MPa, PFOA underwent rapid degradation with near-complete conversion. The incorporation of γ-MnO₂ markedly enhanced the PFOA degradation at low temperature and achieved faster fluorine removal. At the conditions of 300 °C, 40 min, O/C ratio (oxygen-to-carbon molar ratio) = 1.5, and pH = 7, the degradation and defluorination efficiencies increased by 12.56% and 15.21%, respectively, compared with the non-catalytic system. This enhancement is primarily attributed to the efficient activation of H₂O₂ by γ-MnO₂, which promotes the breaking of C–F bond and accelerates the converting of PFOA into CO₂ and fluoride ions. The SEM, Raman and leaching experiment results demonstrated that γ-MnO₂ exhibits excellent structural stability and reusability. Furthermore, density functional theory (DFT) calculations were performed to identify potential reactive sites and elucidate degradation pathways at the molecular level, providing mechanistic support for the experimental observations. Overall, the γ-MnO₂-catalyzed SCWO exhibits excellent degradation and defluorination performance for PFOA removal, providing useful insight into the treatment of fluorinated wastewater. Full article

This study provides a rigorous analysis of the phase stability, mechanical behavior, and surface integrity of a non-equiatomic (FeCoNiCr)₈₅Ga₁₅ high-entropy alloy (HEA). By transitioning from the conventional equiatomic design to a gallium-doped 3d-transition metal matrix, we explore the interplay between lattice distortion and phase separation. Synthesized via vacuum arc melting, the as-cast alloy exhibits a non-homogeneous dendritic morphology consisting of a Cr-Fe-Co rich face-centered cubic (FCC) matrix and Ni-Ga rich body-centered cubic (BCC) interdendritic regions. While global thermodynamic criteria (δ = 3.65, ΔH_mix = −9.28 kJ/mol, and Ω = 2.23) favor single-phase solid solution stability, the Valence Electron Concentration (VEC = 7.46) precisely forecasts this dual-phase structure. Following low-temperature annealing at 250 °C for 24 h, high lattice strain energy drives a significant morphological transformation where the continuous interdendritic network resolves into discrete, phase-separated B2/BCC “islands”. Mechanical and tribological characterizations reveal that this low-temperature thermal activation triggers precipitate hardening; the macro-hardness increases from 146 ± 11 HB to 153 ± 7.5 HB and the micro-hardness rises from 186 ± 4 HV_0.5 to 206 ± 17.5 HV_0.5, yielding enhanced resistance to oxidation-delamination wear. However, electrochemical evaluation in a 3.5 wt.% NaCl solution highlights a fundamental trade-off: the formation of localized galvanic micro-cells between the phase-separated islands and the matrix causes the corrosion current density (i_corr) to increase from ≈10⁻⁹ A/cm² in the as-cast state to ≈10⁻⁶ A/cm² post-heat treatment, accompanied by a heightened susceptibility to localized pitting. These findings elucidate the primary role of electronic structure and minor p-block additions in regulating the lifecycle performance of transition metal HEAs under extreme conditions. Full article

Freezing is an important technique for preserving muscle foods (encompassing mammalian meat, poultry, and seafood). However, traditional thawing methods have several drawbacks, including excessive drip loss, nutrient leaching, and overall quality degradation. To address these issues, emerging technologies such as high-voltage electric field, ohmic, microwave, ultrasound-assisted, low-temperature combined with high-humidity (LHT), radiofrequency (RF), and vacuum thawing have been developed. Despite their potential, existing literature frequently focuses on standalone methods or isolated engineering parameters, leaving a critical knowledge gap regarding their comparative industrial viability and combined synergistic effects. Based on a comprehensive literature search across major scientific databases, the changes in meat product quality during the thawing process were systematically discussed, followed by an exploration of the principles and applications of these innovative methods. Crucially, comparative findings indicate that LHT thawing most effectively preserves water-holding capacity (WHC) and minimizes lipid oxidation. In contrast, RF thawing provides the optimal balance between rapid thawing rates and uniform quality retention for large-scale operations, while hybrid approaches (e.g., microwave combined with ultrasound) successfully balance high-speed processing with the prevention of structural degradation. Furthermore, the practical applications of these technologies in the food industry were presented, emphasizing the growing trend of combining multiple techniques. The advantages and disadvantages of the thawing process are analyzed to provide theoretical references and practical insights for enhancing the quality of commercial meat products. Full article

The Shatt al-Basrah Canal, a brackish artificial waterway in southern Iraq, experienced a fish mortality event in August 2021, raising serious environmental and socioeconomic concerns. This study documents field observations, photographic evidence, and in situ water-quality measurements collected during the event to characterize environmental conditions associated with the mortality and situate them within the context of long-term ecosystem degradation in the region. The event coincided with critically low dissolved oxygen concentrations (1–2.5 mg L⁻¹), elevated summer water temperatures (31.2–31.6 °C), high total ammonia nitrogen levels (1.88–2.2 mg L⁻¹), and brackish salinity (17.4–23 ppt), reflecting strong anthropogenic influence and limited hydrological flushing. These stressors occurred in areas receiving untreated wastewater inputs and affected both native and non-native fish species tolerant of estuarine conditions. Comparison with documented fish-kill events from Kuwait Bay and other parts of the northern Arabian Gulf indicates similar environmental settings characterized by hypoxia, organic enrichment, and summer thermal stress. The 2021 mortality event suggests how acute ecological deterioration may arise in chronically degraded brackish systems and underscores the need for continuous water-quality monitoring, improved wastewater treatment, and proactive management to reduce the risk of recurrent fish kills in Iraq’s vulnerable aquatic ecosystems. Full article

On-site hydrogen refueling stations (HRS) face significant operational challenges due to the stochastic nature of hydrogen demand, creating a severe supply–demand mismatch. Under traditional pressure-based hysteresis control, this volatility forces Proton Exchange Membrane (PEM) electrolyzers into frequent start–stop cycles, accelerating degradation and reducing efficiency. In response, this study introduces an automated control framework integrating macroscopic gas-state modeling with deep-learning-based demand prediction. First, a real-gas thermodynamic model was established. Monte Carlo simulations of 100 random filling scenarios identified a robust design benchmark of 4.5 kg per vehicle. A low filling stability coefficient (5.02%) confirmed that individual thermodynamic fluctuations are negligible, validating a traffic-flow-driven demand approach. Next, a deep Long Short-Term Memory (LSTM) network was developed to forecast short-term demand. Trained on an 8784 h dataset exhibiting “double-peak” traffic patterns, the model achieved high precision on the unseen test set, yielding a Root Mean Square Error (RMSE) of 6.75 kg and a normalized RMSE (nRMSE) of 0.0987, explaining 82% of the demand variance. Finally, an LSTM-informed demand-following control strategy was formulated to enable proactive, thermally bounded operation alongside a novel “Hot Standby” mechanism. Maintaining a minimal 3.0 kg/h holding current during idle periods sustains stack temperatures above 60 °C, effectively mitigating thermal stress. Comparative simulations over 1464 h demonstrated that the proposed framework reduces detrimental cold start–stop cycles by 98.4% (from 61 to 1) and suppresses power output fluctuations by 40.7% compared to the traditional baseline. These results confirm that data-driven control significantly enhances operational stability, facilitates grid integration, and extends core equipment service life. Full article

Low Earth orbit (LEO) satellite systems provide ubiquitous global connectivity for massive grant-free random access Internet of Things (IoT) applications. Full frequency reuse (FFR) improves spectrum efficiency in spectrum sharing scenarios but introduces severe adjacent beam and cross-system co-channel interference. Meanwhile, the high mobility of LEO satellites hinders accurate instantaneous channel state information (iCSI) acquisition, and random direction-of-arrival (DOA) estimation errors cause statistical CSI (sCSI) mismatch, which degrades beamforming performance and makes it difficult to balance transmission robustness, user fairness, and onboard computational complexity. To address these issues, we propose a low-complexity Hybrid Optimized Robust Beamforming (HORBA) algorithm. We first construct a robust joint optimization model to characterize the coupling effects of DOA errors, outdated CSI, and multi-dimensional interference, with constraints on per-user minimum SINR and cross-system interference temperature. Then, based on the block coordinate descent framework, we decouple the original non-convex problem into two convex subproblems, which are solved via generalized eigenvalue decomposition and first-order Taylor expansion, combined with an adaptive sampling mechanism that balances accuracy and complexity. Simulation results verify that our algorithm outperforms typical benchmarks in sum rate and robustness, maintains low onboard processing complexity, and effectively alleviates edge user rate polarization. Full article

Large TiN inclusions degrade the performance and castability of high-titanium wear-resistant steel. The evolution of TiN inclusions in molten steel under La and Mg treatments was comparatively investigated by high-temperature simulation experiments and thermodynamic calculations. In all steels, TiN precipitated and coarsened with prolonged holding time. In Al-deoxidized steel, after 60 min holding following Ti addition, the mean sizes of overall inclusions and complex TiN inclusions were 2.3882 and 3.8350 μm, respectively. With 0.0032% La treatment, Al₂O₃ was modified into finer LaAlO₃, reducing these values to 2.1512 and 2.8749 μm. At a higher La content of 0.03%, Al₂O₃ was transformed into La₂O₂S, and these values instead increased to 2.4135 and 3.6076 μm due to the co-growth of residual La₂O₂S and TiN during Ti alloying. Mg treatment refined inclusions more effectively: under 0.0028% and 0.0062% Mg, overall inclusion sizes decreased to 1.9911 and 1.8743 μm, and complex TiN sizes decreased to 2.2963 and 1.9257 μm due to the formation of finer MgAl₂O₄ and even finer MgO with a low lattice mismatch with TiN. Therefore, Mg treatment, promoting MgO formation, is more promising than La treatment for refining TiN inclusions in high-titanium wear-resistant steel. Full article

To address the durability limitations of conventional crack sealants under coupled extreme temperatures and traffic loads in long-life pavements, a bio-oil composite-modified patching material was developed using 90# base asphalt as the matrix, synergistically modified with crumb rubber (CR) and epoxidized soybean oil (ESO). To resolve the contradictory requirements for high elasticity and thermal expansion/contraction coordination in sealants, ESO was introduced; its polar epoxy groups optimize phase compatibility and promote low-temperature stress relaxation without restricting thermal deformability. Rheological evaluations revealed that the optimal system (OPT) successfully extended the service temperature window from PG 76–−24 °C (baseline) to PG 82–−24 °C, significantly enhancing its adaptability to extreme climatic fluctuations. At −24 °C, OPT exhibited a reduced creep stiffness (S) of 164 MPa and an increased creep rate (m) of 0.312, with a cracking resistance ratio (k) as low as 525.6; the quantitative significance of these metrics lies in granting the sealant superior stress relaxation capacity, enabling it to accommodate dynamic crack widening without interfacial debonding or brittle fracture. Fatigue testing via time sweeps demonstrated that N_f50 reached 2890 cycles, highlighting robust long-term resistance against high-frequency shear strains induced by tire edges. Micro-mechanistic analyses (FTIR, TG/DTG, and DSC) confirmed that the modification is primarily driven by physical blending. The elevation of the thermal decomposition threshold (T5%) to 302.4 °C and the residue at 600 °C to 44.8% provide a critical safety margin for high-temperature construction heating, preventing thermal degradation. Furthermore, the glass transition temperature (T_g) decreased to approximately −35.2 °C. These findings establish a rigorous quantitative and mechanistic framework for designing sustainable, high-performance patching materials for resilient pavement maintenance. Full article

Rotary kiln shell temperature monitoring is essential for metallic shell protection and refractory lining maintenance in high-temperature industrial processes, while smoke, dust, thermal diffusion and non-kiln heat sources make valid shell temperature extraction difficult. This study develops a multi-scale cascaded network with low-resolution space-to-depth downsampling (MSC-LSTD) for infrared kiln shell segmentation and temperature recognition. Global infrared thermal images and local laser temperature measurements are used to construct a calibrated rotary kiln infrared dataset, and predicted kiln shell masks are mapped to temperature matrices for valid shell temperature analysis. MSC-LSTD achieves 99.82% aAcc, 99.14% mAcc and 97.03% mIoU on the rotary kiln infrared dataset, showing robust segmentation performance under complex thermal interference. The proposed framework provides a practical image-based solution for kiln shell overheating warning and refractory lining degradation assessment. Full article

Background: Hot-melt extrusion (HME) is a promising technology for the manufacturing of drug products; however, its application is limited by elevated thermal and shear stresses that may induce degradation of thermolabile active pharmaceutical ingredients. One of the approaches to reducing processing temperatures is the use of polymeric systems with tailored thermal and rheological properties. The aim of the study was to develop an approach for the design of polymeric systems exhibiting a transient plasticization window, enabling a reduction in melt viscosity and improved processability under low-temperature extrusion conditions, followed by the formation of a structurally coherent matrix upon cooling. Methods: The compatibility of the initial polymers was assessed using laser microinterferometry. Based on the obtained data, three- and four-component polymeric compositions were designed and prepared by hot-melt extrusion. The resulting materials were characterized by differential scanning calorimetry, melt rheology analysis, and storage stability assessment. Thermal and rheological data were used to iteratively optimize the polymeric systems. Results: A four-component polymeric system based on PVP K-29/32, PEG 400, PEG 1500, and HPC EF was developed, suitable for processing by hot-melt extrusion at 70 °C. The final system enabled formation of a homogeneous extrudate, exhibited reproducible rheological behavior, and remained stable in the solid-state during storage, with no evidence of cold flow. Conclusions: It was established that, in the design of polymeric systems for hot-melt extrusion, the key factor is not achieving the lowest possible glass transition temperature, but rather the design of a system in which viscosity is transiently reduced under processing conditions and followed by structural stabilization upon cooling. The proposed approach may be applied in the development of polymeric premixes for the preparation of dosage forms by hot-melt extrusion, including those incorporating thermolabile active pharmaceutical ingredients. Full article

Biochar, a carbon-rich material derived from biomass pyrolysis, offers a promising pathway for valorising agricultural and industrial residues within a circular economy. This review analyses the evolution of biochar properties, including fixed carbon content, elemental composition, surface functional groups, porosity, pH, hydrophobicity, and thermal stability, as a function of pyrolysis temperature. The novelty of this work lies in the systematic correlation between the thermal history of biochar and its performance as a functional filler in polymer composites. In fact, increasing temperature enhances carbonisation and aromatic ordering, and in turn induces a transition from hydrophilic to hydrophobic behaviour, thereby promoting micro–mesoporous development. These shifts are critical for compatibility with polymer matrices and thus the production of light-weight, cost-effective, and environmentally friendly composite materials through processes such as melt extrusion and injection moulding. This study highlights how biochar can be tuned for compatibility: low-temperature biochar enhances adhesion in polar systems, while high-temperature biochar favours non-polar matrices, improving stiffness, thermal stability, and electrical conductivity. In biodegradable polymer composites, additional effects on crystallisation behaviour and degradation mechanisms emerge, further highlighting the complexity of designing biochar-reinforced systems. Full article

The present study investigates the solar-assisted photo-Fenton-like degradation of a reactive azo dye (Red SPR) using an iron-based metal–organic framework, MIL-100(Fe), as a heterogeneous catalyst. The synthesized MIL-100(Fe) was successfully characterized by XRD, SEM, EDX, and FTIR analyses, confirming the formation of a crystalline, porous structure with well-dispersed Fe active sites. The catalytic performance was systematically evaluated under various operational parameters, including hydrogen peroxide dosage, catalyst loading, pH, circulation flow rate, initial dye concentration, and temperature. The results demonstrated that optimal degradation efficiency was achieved at pH 3.0, H₂O₂ concentration of 400 mg L⁻¹, and catalyst dosage of 40 mg L⁻¹, while a circulation flow rate of 400 mL min⁻¹ ensured optimal hydrodynamic conditions. The system exhibited rapid degradation kinetics, achieving nearly complete dye removal within 60 min under solar irradiation. Kinetic analysis revealed that the degradation process follows pseudo-first-order behavior, with rate constants increasing from 0.1040 to 0.1589 min⁻¹ as temperature increased from 25 to 55 °C. Thermodynamic analysis indicated that the process is endothermic (ΔH` = 8.72 kJ mol⁻¹) and kinetically favorable with a low activation energy (Ea = 11.32 kJ mol⁻¹), while negative entropy values suggested the formation of an ordered transition state. Radical scavenger experiments confirmed that hydroxyl radicals (•OH) are the dominant reactive species, with secondary contributions from superoxide radicals (O₂•⁻). The enhanced performance is attributed to the synergistic effect of solar irradiation and Fe³⁺/Fe²⁺ redox cycling within the MIL-100(Fe) framework. Hence, the study demonstrates that MIL-100(Fe) is a highly efficient and sustainable catalyst for solar-driven wastewater treatment applications. Full article

The mechanical behavior of lead/rubber bearings (LRBs) is strongly influenced by both ambient temperature and hysteretic heating under seismic loading; however, their coupled effects and underlying mechanisms remain insufficiently understood. This study presents a systematic investigation of the thermo-mechanical response of LRBs through combined experimental and numerical approaches. Dynamic cyclic tests were conducted on full-scale LRBs (700 mm in diameter) over a wide range of ambient temperatures, revealing that ambient temperature and hysteretic heating jointly govern the evolution of key mechanical properties, including stiffness, characteristic strength, and energy dissipation capacity. Specifically, decreasing temperature leads to stiffness and strength enhancement, whereas hysteretic heating induced by cyclic plastic deformation of the lead core results in progressive softening and degradation of restoring force. Based on the experimental observations, a modified uniaxial Bouc–Wen constitutive model is developed, incorporating the coupled effects of ambient temperature, hysteretic heating, and large-strain hardening. The proposed model is implemented in a single-degree-of-freedom (SDOF) base-isolated system to evaluate the seismic response under different temperature conditions. The results reveal a competing mechanism between ambient temperature and hysteretic heating: low temperatures tend to increase base shear and reduce displacement, while hysteretic heating produces the opposite effect, with their relative dominance depending on temperature level and ground motion intensity. Neglecting such thermo-mechanical coupling may lead to significant misestimation of structural response, particularly under long-duration strong ground motions. This study provides new insights into the coupled temperature-dependent behavior of LRBs and establishes a robust modeling framework for the seismic analysis and design of isolation systems under complex service conditions. Full article