Search Results (3,029)

n-Pentanol, a promising biofuel, can reduce greenhouse gas emissions while remaining compatible with internal combustion engines. We present a reduced kinetic mechanism comprising 66 species and 292 reactions that captures both high- and low-temperature ignition and flame propagation dynamics for this fuel. The mechanism, developed by integrating a detailed n-pentanol sub-mechanism with the San Diego mechanism and applying sensitivity and steady-state approximations criteria as reduction strategies, accurately reproduces key phenomena, including the negative temperature coefficient behavior (NTC). Validation against experimental data for ignition delay times, laminar flame speeds, and speciation measurements in a jet-stirred reactor confirms its predictive capability across a wide range of conditions. Full article

The corrosion behavior of austenitic steel HR3C in supercritical CO₂ at 550–600 °C under 25 MPa for 1000 h was investigated. The corrosion kinetics of HR3C were evaluated using weight change measurements. The microstructure and phase composition of HR3C were studied via scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and secondary ion mass spectroscopy. Weight gain data showed that the HR3C exhibited excellent corrosion resistance and that the corrosion kinetics followed a near-parabolic law. The surface of the sample is composed of fine granular oxides, with the main elements including C, O, Cr, Fe and Ni. The oxide phase analysis indicated that protective Cr₂O₃ formed, and a small amount of Fe₂O₃ was also detected. Carbon enrichment was observed on the surface of the outmost layer and the interface of the oxide layer and substrate. The corrosion mechanism and carbon diffusion process are furthermore discussed. Full article

Biomass resources are excellent candidates for carbon electrode materials due to their abundance, renewability, and biodegradability. Herein, the solanaceous crop Tobacco Straw, a rich agricultural by-product, was utilized to prepare biomass-derived carbon material (TsC) and applied as an anode in lithium-ion batteries (LIBs). Doping or composite formation is considered to enhance the electrochemical performance. Doping extra nitrogen (N) atoms into the TsC (denoted as TsNC) demonstrated exceptional reversible specific capacity (475.9 mA h g⁻¹ at the current density of 60 mA g⁻¹ after 500 cycles) and remarkable long-term cycling stability (142.9 mA h g⁻¹ even at a high current density of 1.5 A g⁻¹ after 1000 cycles, much larger than that of TsC), attributed to the increased lithium-ion (Li-ion) adsorption sites including graphitic-N, pyrrolic-N, and pyridinic-N. Furthermore, kinetic analysis revealed that a prominent predominant surface capacitive-controlled behavior was responsible for the superior rate performance of TsNC, which could facilitate rapid charging and discharging at high rates. This work offers valuable insights into the application and modification of nitrogen-doped biomass-derived carbons with outstanding electrochemical properties for LIBs. The strategy also sheds light on enabling waste recycling and generating economic benefits. Full article

Ti–Al alloys have widespread applications as targets in hard coatings by PVD (Physical Vapor Deposition). While the importance of target density is recognized, the densification mechanisms of Ti-67 at% Al targets, particularly during spark plasma sintering (SPS), remain poorly understood, hindering process optimization. This study aims to clarify these mechanisms by fabricating Ti-67 at% Al targets via SPS and examining their densification behavior through a detailed analysis of the creep model based on the stress exponent (n) and apparent activation energy (Q_d). The target’s relative density gradually increased in the temperature range of 370–530 °C, whereas the grain size remained relatively constant, indicating that the densification process dominated during this period. The results reveal that densification is primarily controlled by intergranular diffusion (n ≈ 2, Q_d = 97.29 kJ/mol) and dislocation climbing (n ≈ 3, Q_d = 158.74 kJ/mol). The target’s relative density reached 98.25% at 530 °C, with a corresponding grain size of 10.86 ± 1.08 μm. Additionally, as the temperature increased, the Vickers hardness of the target increased from 61.56 HV to 129.66 HV, and the electrical conductivity rose from 0.23 S/cm to 0.86 S/cm. This work provides a fundamental understanding of the densification kinetics in Ti-67 at% Al alloys during SPS, establishing a crucial guideline for fabricating high-performance PVD targets. Full article

Effective ablative thermal protection systems are essential for ensuring the structural integrity of hypersonic vehicles subjected to extreme aerothermal loads. However, the microscopic reaction mechanisms at the gas–solid interface, particularly under non-equilibrium high-enthalpy conditions, remain poorly understood. This study employs reactive molecular dynamics (RMD) simulations with the ReaxFF-C/H/O force field to investigate the atomic-scale ablation behavior of a graphene-based knitted graphene structure impacted by atomic oxygen (AO). By systematically varying the AO incident kinetic energy (from 0.1 to 8.0 eV) and incidence angle (from 15° to 90°), we reveal the competing interplay between catalytic recombination and ablation processes. The results show that the catalytic recombination coefficient of oxygen molecules reaches a maximum at 5.0 eV, where surface-mediated O₂ formation is most favorable. At higher energies, the reaction pathway shifts toward enhanced CO and CO₂ production due to increased carbon atom ejection and surface degradation. Furthermore, as the AO incidence angle increases, the recombination efficiency decreases linearly, while C-C bond breakage intensifies due to stronger vertical energy components. These findings offer new insights into the anisotropic surface response of knitted graphene structures under hyperthermal oxygen exposure and provide valuable guidance for the design and optimization of next-generation thermal protection materials for hypersonic flight. Full article

Background/Objectives: The pulmonary administration of levodopa enables a rapid absorption and onset of action, making it a suitable administration route for managing OFF episodes in Parkinson’s disease. Currently, one dry powder product for inhalation (Inbrija) is available on the market, while another (Levodopa Cyclops) is in development. These two products differ substantially in terms of inhaler design, their use and resistance, and their powder formulations. This study aimed to investigate whether these differences translate into in vitro differences in aerosol characteristics and dissolution kinetics and whether any differences were also reflected in the in vivo performance. Methods: The in vitro aerosol characteristics were determined via Next Generation Impactor experiments, and the dissolution kinetics were determined with a modified paddle apparatus. A randomized crossover comparative bioavailability study with fasted healthy volunteers was conducted with Inbrija 84 mg and Levodopa Cyclops 45 mg, 90 mg, and 135 mg. Results: The results showed similar aerosol characteristics, but Levodopa Cyclops showed substantially faster dissolution behavior than Inbrija. Despite this in vitro difference, the pharmacokinetic profiles of Inbrija 84 mg and Levodopa Cyclops 90 mg were similar, with no differences in C_max, T_max, and AUC, showing bioequivalence between the two products. Conclusions: This suggests that the systemic absorption of levodopa via the lungs is not limited by dissolution but most likely by its permeation rate. This finding underscores the need to critically apply in vitro tests and critically interpret the results for predicting the in vivo performance of inhaled products. Full article

The sustainable recycling of valuable metals from spent lithium-ion batteries (LIBs) is critical for resource conservation and environmental protection but remains challenging due to the complex coexistence of target and impurity metals. This study systematically investigates the selective leaching behaviors of metals (Co, Li, Cu, Fe, Al) in phosphoric acid media, revealing that lithium could be preferentially extracted in mild acidic conditions (0.8 mol/L H₃PO₄), while complete dissolution of both Li and Co was achieved in concentrated acid (2.0 mol/L H₃PO₄). Kinetic analysis demonstrated that metal leaching followed a chemically controlled mechanism, with distinct extraction sequences: Li > Cu~Co > Fe > Al in dilute acid and Cu > Al~Li > Fe > Co in concentrated acid. Furthermore, we developed a closed-loop process wherein oxalic acid simultaneously precipitates Co/Li while regenerating H₃PO₄, enabling acid reuse with minimal efficiency loss during cyclic leaching. These findings establish a single-step phosphoric acid leaching strategy for selective metal recovery, governed by tunable acid concentration and reaction kinetics, offering a sustainable pathway for LIBs recycling. Full article

With the progressive depletion of conventional oil and gas resources and the increasing demand for alternative energy, organic-rich sedimentary rock—oil shale—has attracted widespread attention as a key unconventional hydrocarbon resource. Pyrolysis is the essential process for converting the organic matter in oil shale into recoverable hydrocarbons, and a detailed understanding of its behavior is crucial for improving development efficiency. This review systematically summarizes the research progress on the pyrolysis characteristics of oil shale under laboratory conditions. It focuses on the applications of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) in identifying pyrolysis stages, extracting kinetic parameters, and analyzing thermal effects; the role of coupled spectroscopic techniques (e.g., TG-FTIR, TG-MS) in elucidating the evolution of gaseous products; and the effects of key parameters such as pyrolysis temperature, heating rate, particle size, and reaction atmosphere on product distribution and yield. Furthermore, the mechanisms and effects of three distinct heating strategies—conventional heating, microwave heating, and autothermic pyrolysis—are compared, and the influence of inherent minerals and external catalysts on reaction pathways is discussed. Despite significant advances, challenges remain in quantitatively describing reaction mechanisms, accurately predicting product yields, and generalizing kinetic models. Future research should integrate multiscale experiments, in situ characterization, and molecular simulations to construct pyrolysis mechanism models tailored to various oil shale types, thereby providing theoretical support for the development of efficient and environmentally friendly oil shale conversion technologies. Full article

Time-lapse microscopy of mesenchymal stem cell (MSC) cultures allows for the quantitative observation of their self-renewal, proliferation, and differentiation. However, the rigorous comparison of two conditions, baseline (A) versus perturbation (B) (the addition of molecular factors, environmental shifts, genetic modification, etc.), remains difficult because morphology, division timing, and migratory behavior are highly heterogeneous at the single-cell scale. MSCs can be used as an in vitro model to study cell morphology and kinetics in order to assess the effect of, for example, gene therapy and prime editing in the near future. By combining static, frame-wise morphology with dynamic descriptors, we can obtain weight profiles that highlight which morphological and behavioral dimensions drive divergence. In this study, we present A/B Cells Policy: a modular, open-source Python package implementing a robust cell tracking pipeline. It integrates a YOLO-based architecture as a two-stage assignment framework with fallback and recovery passes, re-identification of lost tracks, and lineage reconstruction. The framework links descriptive statistics to a transferable system, opening up avenues for regenerative medicine, pharmacology, and early translational pipelines. It does this by providing an interpretable, measurement-based bridge between in vitro imaging and in silico intervention strategy planning. Full article

This article focuses on modeling counterflows within pedestrian social groups in a corridor using the kinetic theory approach, specifically when two social groups move in opposite directions. The term social group refers to a set of pedestrians with established social relationships who stay as close as possible to one another and share a common goal or destination, such as friends or family. The model accounts for interactions both within the same social group and between pedestrians from different social groups. Numerical simulations based on a Monte Carlo particle method are performed. A key criterion for evaluating simulation models is their ability to reproduce empirically observed collective motion patterns. One of the most significant emergent behaviors in bidirectional pedestrian flows is lane formation. To analyze this phenomenon, we employ Yamori’s band index to quantify the evolution of lane structures. Full article

This study concerns the evaluation of adhesive and wettability energetic signatures of a model orthodontic wire exposed to commercial mouthrinses. The surface wetting properties were evaluated from the contact angle hysteresis (CAH) approach applied to dynamic contact angle data derived from the original drop on a vertical filament method. Young, advancing, receding CA apart from adhesive film pressure, surface energy, work of adhesion, etc. were chosen as interfacial interaction indicators, allowing for the optimal concentration and placement of the key component(s) accumulation to be predicted for effective antibacterial activity to eliminate plaque formation on the prosthetic materials. Surfactant compounds when adsorb at interfaces confer rheological properties to the surfaces, leading to surface relaxation, which depends on the timescale of the deformation. The surface dilatational complex modulus E, with compression elasticity E_d and viscosity E_i parts, determined in the stress–relaxation Langmuir trough measurements, exhibited the viscoelastic surface film behavior with the relaxation times (0.41–3.13 s), pointing to the vertically segregated film structure as distinct, stratified layers with the most insoluble compound on the system top (as indicated with the 2D polymer film scaling theory exponent y = 12.9–15.5). Kinetic rheology parameters could affect the wettability, adhesion, and spreading characteristics of mouthrinse liquids. Full article

In this study, canola oil was used as a natural enriched source of C18 fatty acids and coconut oil as a natural enriched source of C12 fatty acids. The study synthesized five potassium carboxylate (RCOO⁻K⁺) liquid soaps via saponification of coconut–canola oil blends (100:0, 75:25, 50:50, 25:75, 0:100) using a novel in situ dissolution method with controlled KOH addition to prevent solid paste formation. The water demand required to dissolve RCOO⁻K⁺ and mitigate soap crystallization was determined, increasing from 1.76 to 5.18 g H₂O/g oil as canola oil content rose, with soap concentration decreasing from 55.1% (100:0) to 18.5% (0:100). Reaction kinetics revealed faster KOH depletion in coconut oil-rich blends (100:0, 75:25, 50:50; 2 h) compared to canola oil-rich blends (25:75, 0:100; 8 h). Key soap properties, including foam stability, detergency, wettability, viscosity, and thermal behavior, were assessed. The 50:50 blend exhibited the highest foam stability due to the synergistic effects of medium-chain saturated (e.g., laurates) and long-chain unsaturated (e.g., oleates) RCOO⁻K⁺. The short, saturated chains promoted rapid foam formation, while the longer, unsaturated chains enhanced foam film stability. RCOO⁻K⁺ detergency on hair tresses with artificial sebum ranged from 16.9% to 29.7% and was relatively higher compared to sodium lauryl sulfate, sodium laureth sulfate, cocamidopropyl betaine, and sodium cocoyl glutamate (6.1–13.2%) but lower compared to sodium isethionates (34.2%). RCOO⁻K⁺ wettability on cotton textiles improved with higher coconut oil content. RCOO⁻K⁺ contact angles on artificial sebum surface (6.1–13.7°) demonstrated excellent wettability, effectively penetrating and emulsifying hydrophobic residues. Viscosity ranged from 13–45 mPa·s with Newtonian Flow-type behavior. No crystals were observed in the soaps when cooled in the range of 60 to −30 °C. These results demonstrate RCOO⁻K⁺ soaps as tunable, sustainable liquid soaps with performance optimized by adjusting the oil blend ratios. Full article

This study investigates the behavior of phosphorus during high-temperature smelting of hydrogen-reduced high-phosphorus oolitic iron ore from the Lisakovsk deposit. The preliminary reduction was carried out at temperatures ranging from 600 to 900 °C using hydrogen, aiming to selectively reduce iron to the metallic phase while retaining phosphorus in the oxide form. The resulting reduced products were subjected to wet magnetic separation and liquid-phase separation. It was found that neither method provides effective separation of phosphorus from iron: phosphorus partially enters the magnetic fraction and, during smelting, transfers into the metallic phase. To confirm the mechanism of phosphate reduction by metallic iron, a control experiment was conducted, in which a mixture of reduced iron and raw ore was smelted at 1650 °C. Microstructural and elemental analyses confirmed the redistribution of phosphorus into the metallic phase. These findings indicate that effective separation of iron and phosphorus cannot be achieved by reduction roasting alone and highlight the need for further studies on slag formation conditions and phase separation kinetics. Full article

To address the coarse and mixed grain phenomena in ultra-large martensitic stainless steel forgings, this study investigated the hot deformation behavior of 04Cr13Ni5Mo martensitic stainless steel under deformation conditions of 950–1200 °C and strain rates of 0.001–0.1 s⁻¹ using Gleeble-1500D thermomechanical simulation tests. Based on the experimental data, the flow stress curves of the steel were obtained, and a dynamic recrystallization (DRX) kinetic model was established. The model was then integrated into finite element software for simulation to verify its reliability, providing theoretical guidance for optimizing high-temperature forging processes. The results demonstrate that dynamic recrystallization in 04Cr13Ni5Mo steel occurs more readily at temperatures above 1050 °C and strain rates below 0.1 s⁻¹. Under the selected hot compression test condition (1100 °C/0.01 s⁻¹), the simulated grain size in the central deformation zone was 48.98 μm, closely matching the experimentally measured value of 48.18 μm. This agreement confirms the reliability of finite element-based prediction and control of grain size in martensitic stainless steel forgings. Full article

Background: Structurally active phospholipoproteomic formulations that lack pharmacodynamic targets or systemic absorption present unique challenges for validation. Designed for immune compatibility or structural modulation—rather than therapeutic effect—these platforms cannot be evaluated through conventional clinical or molecular frameworks. Methods: This study introduces a standardized, non-invasive ex vivo protocol using real-time kinetic imaging to document biological behavior under neutral conditions. Eight human tumor-derived adherent cell lines were selected for phenotypic stability and imaging compatibility. Phospholipoproteomic preparations were applied under harmonized conditions, and cellular responses were recorded continuously over 48 h. Results: Key parameters included signal continuity, morphological integrity, and inter-batch reproducibility. The system achieved high technical consistency without labeling, endpoint disruption, or destructive assays. Outputs included full kinetic curves and viability signals across multiple cell–fraction pairings. Conclusions: This method provides a regulatorily compatible foundation for functional documentation in non-pharmacodynamic programs where clinical trials are infeasible. It supports early-stage screening, batch comparability, and audit-ready records within SAP, CTD, or real-world evidence (RWE) ecosystems. By decoupling validation from systemic exposure, the protocol enables scalable, technically grounded decision-making for structurally defined immunobiological platforms. Full article