Search Results (558)

Background/Objectives: Semaglutide, a long-acting glucagon-like peptide-1 (GLP-1) analog for type 2 diabetes and obesity, requires sensitive and high-throughput bioanalytical methods to support pharmacokinetic studies. However, previously reported liquid chromatography–tandem mass spectrometry (LC–MS/MS) assays have been limited by lengthy run times (~18 min) and suboptimal sensitivity. This study aimed to develop and validate a rapid, sensitive LC–MS/MS method for quantifying semaglutide in plasma. Methods: Plasma samples (50 μL) were prepared by acetone-mediated protein precipitation followed by solid-phase extraction. Chromatographic separation was performed on a Cadenza CD-C18 MF column within 9 min, using positive electrospray ionization in multiple reaction monitoring mode with the transitions m/z 1029.4 → 110.1 for semaglutide and m/z 938.9 → 109.9 for liraglutide (internal standard). Validation followed the U.S. Food and Drug Administration (FDA) bioanalytical guidelines. Results: The assay showed a lower limit of quantification of 1 ng/mL with linearity across 1–500 ng/mL (R² = 0.9999), with sharp peak shape and no carryover. Intra- and inter-day accuracies were 95.69–103.76% and 94.93–100.08%, with precision ≤4.50% and ≤5.88%. Recovery (93.05–107.95%) and matrix effects (96.34–104.12%) were consistent across quality control levels, and the analyte was stable under all tested conditions. The method was successfully applied to a pharmacokinetic study in Sprague–Dawley rats following subcutaneous administration of 50 μg semaglutide. Conclusions: The validated method offers shorter analysis time, improved sensitivity, and reduced sample volume compared with previously reported assays, supporting its application in preclinical pharmacokinetic studies of semaglutide and related GLP-1 analogs. Full article

The blast furnace–basic oxygen furnace long process is the dominant steel production route in China. Increasing the scrap ratio is an effective way to reduce cost and carbon emissions, and scrap preheating is a key technology to achieve a high scrap ratio. To improve the low thermal efficiency and poor deep-bed melting performance of converter gas-based scrap preheating, an innovative process using oxygen-enriched combustion in a hot metal ladle is proposed. Numerical simulation is essential for capturing the complex multiphysics phenomena, as real-time monitoring of melting inside the packed scrap bed is extremely difficult. In this study, a novel multiphysics approach based on a User-Defined Function (UDF) is developed to dynamically track the progressive melting of the scrap skeleton, overcoming the key limitation of conventional enthalpy–porosity models that cannot capture the feedback between phase change and porous medium property evolution. A three-dimensional transient model was established, integrating turbulent combustion, gas–solid convective heat transfer in porous media, and solid–liquid phase change. The effects of impact pit depth, scrap porosity, and converter gas flow rate on temperature distribution, melting behavior, and thermal efficiency were systematically investigated. Results showed that porosity had the strongest influence; thermal efficiency increased from 33.92% to 65.59% as porosity rose from 0.6 to 0.8, due to a transition from conduction-dominated to coupled convection–conduction heat transfer. Converter gas flow rate exhibited a non-monotonic effect, peaking at 3688.14 m³·h⁻¹, highlighting a trade-off between energy input and gas residence time, while impact pit depth showed a limited effect with diminishing returns. A 600 s full-process simulation revealed stage-dependent melting, and the initial phase was crucial for process optimization. The optimal condition, with a pit depth of 64 cm, porosity of 0.8, and converter gas flow rate of 3688.14 m³·h⁻¹, achieved a 1.23% melting fraction and 65.59% thermal efficiency within 120 s. These findings clarify the combined roles of geometric confinement, permeability, and energy-residence time interactions, providing guidance for industrial scrap preheating design. Full article

The development of bio-based active packaging materials has gained increasing attention as a sustainable alternative to synthetic plastics. In this study, chitosan-based films incorporating yerba mate kombucha infusion (YMK-I) were developed and fully characterized. Films were prepared using different YMK-I concentrations (25–100% v/v) as solvent, with acetic acid-based chitosan films as controls. The infusion showed pH 2.5, titratable acidity of 3.5%, total solids of 6%, high phenolic content (1085 mg GAE/L), and reducing sugars (18.3 g/L). Acetic and lactic acids were identified by high-performance liquid chromatography (HPLC). Minimum Inhibitory Concentration (MIC) values ranged from 0.03 µg/mL for Staphylococcus aureus to 0.3 µg/mL for Escherichia coli and Pseudomonas aeruginosa. Rheological results indicated that YMK-I performed similarly to acetic acid as a solvent. Fourier Transformed Infrared with Attenuated Total Reflectance (FTIR-ATR) suggested interactions between chitosan and bioactive compounds. Thermal analyses showed that YMK-I acted as a plasticizer and introduced thermolabile components, altering glass transition and degradation behavior. Increasing YMK-I content reduced tensile strength and increased elongation, indicating greater flexibility, while water vapor permeability increased due to hydrophilic compounds. Films enriched with YMK-I exhibited high antioxidant activity (Radical Scavenging Activity > 85%) and strong antimicrobial effects (>98% inhibition) against E. coli and S. aureus. These results highlight the potential of chitosan–kombucha films as multifunctional materials for specialized applications. Full article

The successful application of extrusion-based 3D-printed geopolymer mortars largely depends on precursor chemistry, activator composition, mixture proportions, and fresh-state behavior, which is highly sensitive to time-dependent structural build-up. This review examines the relationships among mix design, geopolymerization chemistry, rheological properties, and printability requirements for 3D-printed geopolymer mortars. Particular emphasis is placed on the effects of precursor type, alkaline activator characteristics, liquid-to-solid ratio, additives, and fibers on flowability, yield stress, viscosity, extrudability, buildability, shape retention, and interlayer bonding. The review further discusses how geopolymerization kinetics influence the evolution of fresh-state properties, the printable time window, and the transition from extrusion to structural stability. In addition, early-age performance is evaluated in terms of setting behavior, green strength development, and layer-interface integrity. Current challenges, including the lack of standardized test methods, limited comparability among published studies, and the complex coupling between material design and process parameters, are also highlighted. Finally, the review identifies key research gaps and proposes future directions for developing robust, printable, and sustainable geopolymer mortar systems for additive manufacturing in construction. Full article

This study utilizes a large-scale numerical simulation model to investigate the hydrodynamic behavior and particle transport characteristics of gas–liquid–solid three-phase flow in vertical wellbores featuring multi-source confluence and curved geometries. Simulation results indicate that increasing flow velocity shifts the dominant control mechanism from surface tension to inertial forces, transitioning the flow pattern from slug flow to churn flow. In curved pipe sections, centrifugal phase separation and geometric shielding effects cause significant flow asymmetry and maintain large bubble stability at the inner wall. Additionally, the multi-inlet structure induces shear rate gradients that result in the spatial coexistence of two distinct bubble scales. Furthermore, localized gas concentrations exceeding 70% at the upper inlet can trigger severe gas-locking phenomena and intense pressure pulsations. Full article

To elucidate the mechanisms responsible for high friction in micro-pillared soft tribo-contacts under wet conditions, this study investigates the liquid migration behavior across elasticity interfaces featuring bionic surface textures and examines the influence of this migration on interfacial friction properties. Micro-pillar bionic surface textures were fabricated on polydimethylsiloxane (PDMS) substrates. In situ observation of liquid migration and corresponding friction tests were systematically conducted using custom-built experimental setups on soft interfaces textured with micro-pillars of varying area densities. The results demonstrate that both geometrical shape and area density of surface textures play a critical role in regulating liquid migration behavior. Surface textures with circular and hexagonal geometries exhibit optimal migration rates, attributed to their smooth structural profiles, which reduce flow resistance within the microchannels. Liquid migration efficiency is effectively improved with increasing area density of the bionic surface texture owing to strengthened capillary forces. Correspondingly, bionic surface textures exhibiting superior liquid migration characteristics show the smallest relative reduction in friction force during transitions from dry to wet frictional states. This behavior is primarily attributed to the surface’s exceptionally rapid drainage capability, which effectively mitigates the adverse effects of interfacial liquid films on friction. Specifically, rapid liquid removal increases the effective solid–solid contact area and enhances mechanical interlocking at the interface. Consequently, these surfaces maintain outstanding frictional performance even under humid or wet conditions. These findings provide important theoretical support for the rational design of surface microstructures and the optimized regulation of friction and liquid film in wet contact conditions. Full article

Background/Objectives: Gliclazide’s limited water solubility restricts its absorption across the gastrointestinal tract and compromises its therapeutic performance. This study developed a thermoresponsive solid dispersion based on the inverted thermoresponsive behavior of poloxamer 188 in propylene glycol. Methods: A solubility study was conducted to select components for the thermoresponsive solid dispersion. An I-optimal mixture design was used to optimize the concentrations of the thermoresponsive solid dispersion components (poloxamer 188, propylene glycol, and labrasol). FTIR and XRD were used to investigate the mechanism underlying the inverted thermoresponsive behavior. Finally, the influence of the thermoresponsive solid dispersion on gliclazide dissolution was evaluated through in vitro dissolution testing. Results: Surfactant screening identified labrasol as the optimal surfactant owing to a superior increase in gliclazide solubility compared to propylene glycol alone (2.29-fold). The optimized thermoresponsive solid dispersion (poloxamer 188, propylene glycol, and labrasol at 13.89, 21.43, and 64.68% w/w, respectively) achieved a drug solubility of 10.68 mg/g and a phase transition temperature of 36 °C. XRD and FTIR confirmed that hydrogen bonding is responsible for the system’s conversion between the solid and liquid states. Compared with raw gliclazide, the optimized formulation demonstrated an 8.4-fold increase in the initial dissolution rate and significantly improved dissolution efficiency from 21.77 ± 4.74% to 74.85 ± 2.33%. Conclusions: The present thermoresponsive solid dispersion provides a green alternative to conventional solid dispersion techniques. It avoids reliance on organic solvents, processing that demands high energy input, and additional post-processing operations. Full article

Liquid crystal physical gels (LCPGs) combine the anisotropic properties of liquid crystals with the structural stability of soft solids. In this work, MBBA-based LCPGs were prepared using chiral oxalamide gelators 1,6-bis((O-leucylmethanol)-N-yloxalamido)hexane (6-O-Me) and 1,9-bis((O-leucylmethanol)-N-yloxalamido)nonane (9-O-Me) and thoroughly characterized for their thermal, rheological, and electrorheological behaviours. Techniques included differential scanning calorimetry, oscillatory rheology, electrorheological testing, and advanced microscopy analysis. A custom microfluidic device was developed for in situ application of an electric field and optical assessment of its influence on microstructure formation. Both gels exhibited distinct gel-like behavior, with storage moduli consistently exceeding loss moduli and sustained network stability under both short- and long-term deformations. The gelators had minimal effect on the isotropic–nematic transition of MBBA but efficiently delayed crystallization, extending the stability window by −8 °C for 9-O-Me and −14 °C for 6-O-Me. When subjected to electric fields, the gel network weakened in the nematic phase, and the fiber assembly during cooling was altered, resulting in the formation of thicker, anisotropic fibers, consistent with microscopic observations. These results illustrate how the properties of LCPGs can be tuned through molecular design and external stimuli, expanding their potential for stimuli-responsive soft matter applications. Full article

Nickel–aluminum bronze (NAB) propellers can be severely damaged by the synergistic action of chloride corrosion and solid–liquid erosion in marine environments. However, the direct application of micro-arc oxidation (MAO) to NAB is fundamentally hindered because NAB is a non-valve metal. Herein, this limitation is circumvented via a novel hybrid strategy integrating friction stir welding (FSW) and MAO. A defect-free aluminum transition layer is first fabricated onto NAB by FSW and thinned to ~30 μm for MAO. An Al₂O₃-based composite ceramic coating is synthesized, exhibiting a duplex structure with α/γ-Al₂O₃ and an amorphous Si-O network. The coating demonstrates a nano-hardness of 16.2 ± 2.0 GPa and an elastic modulus of 251.3 ± 31.1 GPa, underpinned by a robust interfacial tensile strength of 72.7 MPa. In 3.5 wt.% NaCl, the corrosion current density is suppressed to 1.335 ± 0.151 × 10⁻⁷ A/cm², while the charge transfer resistance reaches 3.072 × 10⁵ Ω·cm². Mass loss after 30-day immersion is reduced to ~1/11 of NAB, and erosion loss at 400 rpm is ~1/8 of that of the substrate. Electrochemical results indicate that the Al transition layer provides an initial beneficial contribution, while the MAO ceramic coating further delivers the dominant barrier protection, together leading to the best overall corrosion resistance of the hybrid-treated sample. Full article

Thermo-electromagnetic force plays a crucial role in tailoring the solidification microstructure by altering thermal-solutal buoyancy. However, while in situ synchrotron experiments offer some observations of microstructural evolution, their restricted spatial resolution and beam intensity prevent the full characterization of fluid flow and solute transport during solidification. To address this limitation, a calibrated model of a cellular automaton method coupled with a Eulerian multiphase approach is employed in this study to comprehensively investigate the impact of solute distribution on grain evolution during the directional solidification of an Al-2.5 wt.% Cu alloy under varying steady magnetic fields from 0.5 T to 4.0 T. The model incorporates heat and solute transport, nucleation, grain growth, and complex melt flows driven by thermal-solutal buoyancy, alongside thermo-electromagnetic effects and induced Lorentz forces. Simulations reveal that under a steady 0.5 T magnetic field, an elliptical copper-rich region forms near the solidification front. This solute redistribution significantly influences the development of a tilted solid–liquid interface, consistent with experimental observations. As the magnetic field strength increases, this copper-rich region transitions from an elliptical to a circular morphology. Notably, under a 4.0 T magnetic field, the tilted interface is effectively stabilized due to the suppression of grain growth. Furthermore, significant grain refinement is observed under a steady magnetic field, as the average grain size decreases from 209.3 μm without magnetic field to 122.5 μm of 0.5 T. This refinement is driven by redistribution of the copper concentration, which increases the undercooling from 1.4 K to 3.7 K and generates new nucleation zones. This solute-driven mechanism is identified as the primary cause of grain refinement under steady magnetic fields and is successfully validated by experimental results. These results shed new light on the mechanism of grain growth evolution under a steady magnetic field. Full article

In fecal sludges (FSs) from non-sewered sanitation systems, bound moisture constituted 46–67% of total moisture across all sanitation types investigated, yet the energetic basis for its resistance to removal has not previously been characterized. Existing classifications of moisture fractions lack quantitative binding energy data, leaving the thermodynamic limits of solid–liquid separation undefined for FS. This study investigates the distribution and binding energies of bound moisture fractions in FS obtained from ventilated pit latrines, urine-diverting dehydrating toilets, and septic tank systems. Bound moisture fractions were determined using moisture sorption isotherms, low-temperature convective drying, nuclear magnetic resonance, and thermogravimetric–differential scanning calorimetry analyses. Results show that interstitial moisture constituted 37–50% of total moisture, followed by vicinal (6–14%) and intracellular (3–9%) fractions, with net isosteric heat rising sharply below 20–30% moisture content (w.b.). Evaporation enthalpy exceeded that of bulk water at moisture contents below ~30% (w.b.), consistent with EPS-mediated adsorption and capillary confinement contributing to increased energy requirements for moisture removal and indicating a transition from capillary-controlled to structure-influenced retention. These findings provide a thermodynamic basis for interpreting why conventional mechanical dewatering stalls at a residual moisture content that differs systematically between VIP, UDDT, and septic tank sludges. These insights are relevant for improving FS treatment strategies, particularly in selecting appropriate combinations of dewatering, drying, and pre-treatment processes. Full article

Double-wall drill pipe reverse circulation drilling is expected to alleviate cutting-transport difficulties and the high risk of lost circulation during the shallow-section drilling of ultra-deep wells. Based on wellbore hydraulics theory and a transient solid–liquid two-phase flow model in the wellbore, considering the flow path transition effect at the reverse circulation converter near the bit, a corrected pressure loss method for the inner pipe accounting for cuttings influence is proposed, and a correlation for calculating the converter pressure loss is derived. A wellbore pressure calculation model for reverse circulation drilling using a double-wall drill pipe is then established. Furthermore, the influencing factors are investigated through sensitivity analysis, and a pump pressure selection chart is developed. Field-case calculations indicate that, under identical operating conditions, the bottomhole pressure in double-wall drill pipe reverse circulation drilling is reduced by approximately 6.31 MPa compared with conventional drilling. For shallow sections (well depth of about 1200 m) under flow rates of 20–40 L/s and drilling-fluid densities of 1200–1400 kg/m³, the maximum total circulating wellbore pressure loss, after incorporating surface flowline pressure losses, is approximately 10.91 MPa. In this case, a single pump can satisfy the circulation requirement, demonstrating the advantages of simplified equipment configuration and improved field adaptability for shallow-section operations. The proposed model and charts can provide a reference for parameter optimization and pressure-control design in double-wall drill pipe reverse circulation drilling. Full article

In this paper we investigate the use of sucrose as a reducing agent for the carbothermal reduction in spent ternary cathode materials. During this process, lithium from the cathode material is converted into water-soluble Li₂CO₃, while the high-valent transition metals are reduced to insoluble metallic elements and oxides. The influence of various pyrolysis temperatures, sucrose dosages, and pyrolysis times on the reduction degree of high-valent metals. Furthermore, the influence of leaching conditions on lithium recovery efficiency is examined. Under the optimal conditions of a pyrolysis temperature of 650 °C, a sucrose dosage of 15 wt.%, a pyrolysis time of 30 min, a leaching solid–liquid ratio of 30 g/L, and a leaching time of 30 min, the lithium leaching rate reaches 97.9%. Characterization via XRD, XPS and SEM reveals that sucrose serves as an effective carbothermal reducing agent. It facilitates the reduction of high-valent transition metals to insoluble metallic elements and oxides while simultaneously enabling the recovery of lithium as Li₂CO₃. Consequently, this method achieves an efficient separation of lithium from other metallic elements. Compared to traditional recycling processes, it avoids the low lithium recovery rates often associated with subsequent separation steps. Full article

The phase transformation characteristics of Sn-Pb-Bi ternary alloys with four representative Bi/Pb mass fraction ratios (0, 0.14, 0.33, and 0.60) were systematically investigated using the deep potential molecular dynamics (DeePMD) method over a temperature range of 300–600 K. A high-precision machine-learned interatomic potential was achieved using large-scale ab initio molecular dynamics (AIMD) datasets, reaching chemical accuracy (energy error <5 meV/atom, force error <100 meV/Å). Complete solid–liquid–solid heating–cooling cycle simulations were performed to accurately determine the melting temperature $T_m$, solidification temperature $T_s$, and undercooling $\Delta T$. The microscopic mechanisms through which Bi regulates phase transitions were revealed through radial distribution function (RDF), mean square displacement (MSD), self-diffusion coefficient, and viscosity analyses. Our results show that increasing the Bi/Pb ratio monotonically lowers $T_m$ from 475 K to 450 K, while $\Delta T$ reaches a maximum of ~48 K at Bi/Pb = 0.14. Bi addition disrupts short-range order, enhances chemical homogeneity, suppresses atomic diffusion, and optimizes liquid viscosity, with the optimal composition found to be Bi/Pb ≈ 0.14, balancing a low melting point, controlled undercooling, and improved flowability. This study provides an atomic-scale theoretical foundation for the precise composition design of low-melting-point Sn-Pb-Bi solders for photovoltaic and electronic packaging applications. Full article

This study systematically investigates the gas–liquid phase transition heat transfer characteristics and volatilization loss behavior of magnetic liquid sealing devices under high-temperature and high-speed operating conditions. A magneto-thermal flow-coupled numerical model was established using ANSYS Maxwell (2025 R1) and Fluent (2025 R1) software to simulate and analyze the influence of rotational speed, solid content, and shaft diameter on the temperature distribution and gas-phase evolution of the magnetic liquid within the sealing gap. An experimental platform was also constructed for validation. The research indicates that increasing rotational speed significantly intensifies the vaporization of magnetic liquid, with bubbles migrating towards lower-concentration regions. The influence weight of rotational speed on phase transition is greater than that of shaft diameter. Under identical temperature fields, the phase transition interface morphology and the proportion of gas–liquid two-phase regions among magnetic liquids with different solid contents are highly similar. However, high-solid-content magnetic liquid can inhibit phase transition due to dense particle packing. Increasing shaft diameter notably expands the vaporization region, easily forming through-leakage channels. Full article