Search Results (2,823)

This study focuses on a novel three-span hybrid continuous beam bridge, analyzing the force performance and key design parameters of the non-cellular post-support plate joint. A finite element model and parametric analysis were used to reveal the stress distribution patterns, the load-bearing characteristics of the connectors, and the load transfer path under negative bending moments. The study shows that the axial force within the joint is equitably shared among three load paths: the top slab concrete (20.7%), the bearing plate (40.1%), and the shear connectors (39.2%). Although interfacial friction contributes approximately 27.1% to the total shear resistance, it is conservatively recommended to neglect this effect in design due to inherent uncertainties. Parametric analysis reveals distinct marginal effects and efficiency thresholds: increasing the bearing plate thickness from 20 mm to 100 mm results in a mere 1.0 MPa reduction in the peak concrete stress, while extending the joint length beyond 1.0 times the beam height renders the central connectors ineffective. Furthermore, reducing the connector stiffness effectively lowers the non-uniformity coefficient from 2.3 to below 2.0. Notably, the first row of web PBLs carries 34.8% to 47.2% of the total shear force, with a stable non-uniformity coefficient of 1.05–1.06, establishing it as the critical control section for simplified design. These findings provide a theoretical basis and practical guidance for the design of similar joints in hybrid girder bridges. Full article

Al-Cu-Fe quasicrystalline coatings were deposited on AISI 321 stainless steel substrates by high-velocity oxy-fuel (HVOF) spraying at oxygen pressures of 3.0, 3.5, and 4.0 bar. The influence of oxygen pressure on the phase composition, microstructure, porosity, corrosion behavior, thermal stability, and microhardness of the coatings was investigated using X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM/EDS), ImageJ porosity analysis, electrochemical corrosion testing in 3.5 wt.% NaCl solution, simultaneous thermal analysis (TGA/DSC), and microhardness measurements. XRD analysis revealed the formation of quasicrystalline-related intermetallic phases together with Al, Fe₃Al₁₃, FeAl, Fe₃O₄, CuFe₂O₄, Cu₂O, and CuO phases. The coating deposited at 3.5 bar exhibited the lowest porosity (5.37%), the most homogeneous microstructure, and the largest residual coating thickness after corrosion testing. SEM and EDS analyses indicated that corrosion preferentially initiated at pores, splat boundaries, and phase interfaces, while the coating produced at 3.5 bar demonstrated the most stable surface condition after exposure to a 3.5 wt.% NaCl solution. Thermal analysis showed that all coatings remained stable up to 900 °C. Sample (a) exhibited the lowest mass loss and the highest thermal stability, whereas sample (b) demonstrated the most favorable combination of structural integrity, phase ordering, coating density, corrosion-related performance, and thermal stability. Microhardness values of the coatings ranged from 754 to 778 HV, significantly exceeding that of the AISI 321 substrate. The results demonstrate that oxygen pressure is a critical parameter controlling the microstructure and functional properties of HVOF-sprayed Al-Cu-Fe coatings, with 3.5 bar providing the most balanced set of properties. Full article

Background/Objectives: The aim of current study was the significant improvement of both the flowability and the compressibility of mesoporous silica microparticles (MSMs), to enable the formulation a potential drug delivery system. MSMs are of emerging interest in the pharmaceutical industry, due to their numerous advantages and versatile applicability, such as improvement in aqueous solubility and epithelial permeability, thus enhancing the oral bioavailability of drugs. However, the formulation of these types of materials has been a major challenge. This problem originates from poor powder flow characteristics due to particle properties. Methods: A binder-free high-shear wet granulation (HSWG) process was performed to improve the flowability and compressibility of the model material, meanwhile preserving its porosity. The prepared granules were characterized by particle size, size distribution, yield percentage, particle morphology, porosity, powder flowability, crushing strength, and stability. Micro-CT measurements were performed to examine the structure of the granules and to see the internal segmentation resulted by the two-step granulation process. The granules were compressed into tablets to evaluate the compressibility behavior based on the models of Kawakita and Walker. The physical parameters of the compressed tablets, such as breaking hardness, tensile strength, and thickness, were tested. Results: The prepared granules were evaluated successfully according to the mentioned properties and found to be satisfactory compared to the raw materials. The binder-free method appeared to be effective, thus the use of binders may be avoided if the process is designed well and critical process parameters (CPPs) selected carefully. The granules showed good stability over a one-year testing period. The micro-CT test also verified the success of the initial concept of preparing core–shell structured granules, and enabled the determination of macropores. Nevertheless, the results were completed with BET measurements to determine specific surface area of the granules. Conclusions: The effect of the critical process parameters of the granulation process on all the mentioned attributes was investigated and since major differences were observed between the batches, the effect of the selected CPPs were also verified. Full article

Seawater intrusion presents a significant risk to coastal aquifers, particularly in low-lying locations where groundwater resources are intensively exploited. This study assesses the vulnerability of the Keta Strip aquifer in Southeastern Ghana to seawater intrusion using the GALDIT model; a widely applied index-based approach that evaluates seawater intrusion risk based on six key hydrogeological indicators: groundwater occurrence (G), aquifer hydraulic conductivity (A), groundwater level above sea level (L), distance from the shoreline (D), impact of existing intrusion (I), and aquifer thickness (T). These parameters were analyzed using data from 105 monitoring wells within a Geographic Information System (GIS) environment. The resulting vulnerability index was spatially grouped into four categories: low, moderate, high, and very high vulnerability. Results indicate that very high and high vulnerability regions are predominantly clustered along the coastal margins and central portions of the study area, driven mainly by low hydraulic gradients, proximity to the shoreline, and high hydraulic conductivity. Moderate vulnerability zones dominate inland areas, while low vulnerability zones are limited and confined to northern sections. Sensitivity analysis reveals that hydraulic head (L) and distance from shoreline (D) are the most influential parameters, whereas TDS exhibits relatively low contribution to overall vulnerability. The findings highlight the critical role of hydrogeological controls and anthropogenic pressures in shaping seawater intrusion risk and provide a scientific basis for sustainable groundwater management in the Keta Strip and similar coastal environments. Full article

Acute or chronic rotator cuff tears are major causes of shoulder dysfunction, motivating the development of scaffolds with tailored thickness and mechanics for supraspinatus tendon regeneration. This study aimed to investigate the effect of bilayer poly(butylene adipate-co-terephthalate) (PBAT) scaffold thickness on the tenogenic differentiation of rat adipose mesenchymal stem cells (r-AdMSCs) and supraspinatus tendon regeneration. Aligned fibers with a diameter of approximately 476 nm were deposited onto randomly oriented layers at different times (4 h; 4S, 6 h; 6S, 8 h; 8S), and scaffolds with increasing thicknesses from 441 µm (4S) to 1132 µm (8S) were produced. Mechanical testing showed comparable tensile strength for 4S and 6S (≈1.9–2.0 MPa) and modulus (5.5–7.3 MPa), while 8S exhibited markedly reduced stiffness (0.5 MPa) and hyper elastic deformation. Mechanical performance across degradation conditions remained strongly thickness-dependent: thinner scaffolds retained integrity and strengthened, with modulus increases during hydrolytic and enzymatic degradation, whereas thicker matrices showed limited remodeling and instability. Rat-AdMSCs’ were cultured on the scaffolds for 21 days. Cell-free and cell-laden mechanical responses further reflected thickness effects: cell-free samples stiffened due to media-induced passive matrix tightening, whereas cell-laden scaffolds showed extracellular matrix (ECM)-driven reinforcement, most prominently in 4S, which reached 2.1 MPa tensile strength with improved elasticity and balanced deformation. The 4S scaffold exhibited the highest tensile strength and significantly increased collagen-1 (col1), tenomodulin (tnmd) and scleraxis (scx) expression compared with the other groups. In conclusion, among all groups, 4S scaffolds demonstrated the most favorable mechanical and biological performance, suggesting that scaffold thickness plays a critical role in regulating tendon regeneration and will become even more suitable when matured in bioreactors. Full article

Residual stress (RS) is a key integrity parameter after welding and additive manufacturing, motivating portable sensing methods for in-situ assessment. Phased Array Ultrasonics for Residual Stress (PAURS) treats a phased-array probe as a time-of-flight (ToF) sensor and infers RS from ToF changes of the longitudinal critically refracted (LCR) wave propagating near the surface. In practical deployments, however, the ToF sensing chain can be susceptible to systematic bias from sensor–specimen interface variability (couplant layer thickness) which can dominate the inferred stress uncertainty if not quantified and corrected. This study combines numerical modelling with experimental validation to (i) characterise couplant-induced sensitivity in LCR ToF sensing, (ii) propagate this effect into RS error/uncertainty, and (iii) demonstrate a model-informed compensation strategy suitable for practical calibration workflows. Simulations show that couplant thickness variations can introduce RS errors of ~36 MPa (~13% of yield strength). The proposed compensation reduces ToF bias to 0 ns under idealised simulated conditions and to ~0.3 ns in experiments, corresponding to ~1.1 MPa RS error (~0.4% of yield strength). These results provide configuration-specific guidance for sensor calibration and uncertainty reporting in phased-array ultrasonic RS sensing, and establish a foundation for future in-process sensing of residual stress and microstructure evolution. Full article

Background: Critically ill patients experience rapid muscle wasting during their ICU stay. Ultrasound (US) and bioelectrical impedance analysis (BIA) are widely used to assess muscle mass; however, their accuracy may be affected by fluid balance alterations. This study aimed to compare the reliability of US and BIA in detecting muscle loss under varying fluid balance conditions in ICU patients. Methods: In this prospective observational study, adult ICU patients with an ICU stay of ≥7 days were evaluated on Days 1, 5, and 7. Muscle thickness was measured using US, and phase angle (PhA) using BIA. Cumulative fluid balance, C-reactive protein (CRP), and lactate levels were recorded. Patients were stratified according to cumulative fluid balance. Results: A total of 143 ICU patients were included in the final analysis. US demonstrated a progressive decrease in muscle thickness (−3.54% ± 10.90% from Day 1 to Day 5 and −7.56% ± 11.82% from Day 1 to Day 7 (both p < 0.0001)), whereas BIA showed no significant change in PhA. Positive fluid balance significantly reduced PhA compared with the negative balance group, p < 0.001, whereas no statistically significant effect on US measurements was detected. CRP > 200 mg/L was associated with greater US-detected muscle loss on Day 5, while lactate > 2.5 mmol/L was associated with lower PhA. Conclusions: Ultrasound reliably identified structural muscle wasting in critically ill patients, with no statistically significant effect of fluid balance detected in this cohort. Furthermore, ultrasound measurements were associated with inflammation-related muscle loss. In contrast, BIA was strongly influenced by hydration and perfusion status, limiting its ability to assess true muscle mass loss in the ICU setting. Full article

Oscillating water column (OWC) wave energy converters equipped with dielectric elastomer generators (DEGs) represent a promising technology for harnessing ocean wave energy. This study emphasises the critical role of functional specifications in guiding the development of these devices from initial concept to full-scale deployment. A comprehensive analysis of key design parameters that influence the performance and efficiency of flexible OWCs with DEG-based power take-off systems is presented. This investigation focuses on the effects of draft, membrane diameter, deformation characteristics, number of layers, and membrane thickness on power output. Utilising a combination of analytical tools, including Wave Venture software, MATLAB, and Abaqus, detailed simulations and analyses are conducted to optimise these parameters. Our results demonstrate that increasing the DEG diameter significantly enhances power output, with diameters between 5 and 12 m showing optimal efficiency. A critical strain threshold of approximately 32% is identified, beyond which power output efficiency diminishes. Furthermore, the study reveals that multi-layer DEG configurations can substantially increase energy production, with thinner membranes generally yielding higher outputs. These findings provide valuable insights for developing functional specifications that balance performance, manufacturability, and long-term reliability in marine environments. This research advances OWC technology by offering a parameter-screening framework to guide device design towards optimised configurations and to accelerate the path to commercial viability in the wave energy sector. Full article

Ferroelectric (FE) diodes configured in the metal–ferroelectric–metal (MIFM) structure are promising candidates for non-volatile memory. While recent studies emphasized bulk FE properties, interfacial characteristics have not been carefully considered. In this work, we investigate the HfO₂/Al_0.8Sc_0.2N interface by examining its impact on switching and rectifying characteristics in MIFM FE diodes with variable HfO₂ thicknesses (2/4/6 nm). Electrical characterization reveal that the increased HfO₂ thickness raises the coercive field (E_C) due to enhanced electrostatic effects and progressive interfacial oxidation from Sc-N to Sc-O bonds. This resulting oxygen substitutional defect (O_N) which may contribute to domain-wall pinning and reduced rectifying efficiency. Cycling tests clarify operating regime-dependent phenomena, including O_N redistribution-induced wake-up and eventual breakdown. Moreover, enhanced retention is observed after pre-cycling, originating from the stabilization of the interfacial defects rather than bulk properties. These findings underscore that E_C and device reliability are likely influenced by interfacial engineering, which is critical for the reliable operation of AlScN-based FE diodes. Full article

Total suspended solids (TSS) have been shown to damage the structural integrity of fish gills, impairing their function, including gas exchange. However, studies showing linkages between gill damage due to TSS and fish performance are limited. There is a large diversity of fish species inhabiting aquatic environments, and whether the TSS impact on gill function is similar across a range of species has yet to be explored. Here, we exposed multiple species, including salmonids (rainbow, brook and cutthroat trout) and cyprinids (fathead minnow and longnose dace) to a range of TSS concentrations (0–1000 mg L⁻¹) for 4 d and assessed damages to gill structure (filament thickness, lamellae thickness, oxygen diffusion distance, lamellae length, epithelial lifting, and interlamellar distance) using confocal microscopy. All species tested showed similar gill structural damage, including thicker lamellae, longer oxygen diffusion distances, and reduced respiratory surface area, at concentrations ≥ 100 mg L⁻¹ TSS. To assess whether gill damage corresponds to performance dysfunction, we tested the metabolic rate and swimming capacity of a salmonid (rainbow trout) and a cyprinid (fathead minnow) after exposure to 100 mg L⁻¹ TSS using swim tunnel respirometry. Trout showed lower routine metabolic rate (RMR) and maximum metabolic rate (MMR) after TSS exposure and were unable to reach the higher swimming speeds attained by unexposed fish. Fathead minnows showed no difference in the RMR after TSS exposure, but, like trout, had a lower MMR and were unable to attain the higher swimming speed of the control fish. Both species showed a ~35% reduction in the critical swimming speed (U_crit). These findings reveal that environmentally realistic TSS concentrations damage gill structure, impair fish swimming performance, and may compromise their ability to cope with energy-demanding activities, including additional biotic and abiotic stressors. Full article

The trend in the power electronics industry toward higher power density and efficiency has brought high-frequency transformers (HFTs) to the forefront of critical applications, including isolated DC–DC converters, electric vehicle chargers, and solid-state transformers. This paper focuses on the leakage inductance of HFTs and presents a systematic comparative framework that evaluates five surrogate modeling and hybrid optimization approaches for the rapid and accurate estimation of leakage inductance. A comprehensive parametric dataset was constructed, comprising 1210 finite element analysis simulations conducted via finite element analysis in the ANSYS Maxwell 2024 R1 environment, varying the number of winding turns, primary winding thickness, and secondary winding thickness of the HFT. All five methods were trained and evaluated on the same dataset under identical conditions. The comparative evaluation demonstrates that the proposed hybrid Gray Wolf optimizer–artificial neural network (GWO-ANN) framework achieved the highest prediction accuracy (R² = 0.9832, MSE = 0.01780, MAE = 0.0935 µH) and the fastest convergence among all tested approaches. The generalization capability of the proposed model was confirmed through blind validation tests across six geometric configurations spanning the full range of the design space, yielding a maximum prediction error of 8.15% and an average error of 2.14%. The functional validity of the proposed parameters was further tested in a third validation layer using MATLAB/Simulink R2024b transformer circuit studies, demonstrating a theoretical efficiency of 96.06%. This three-layer validation approach proves both the parametric and functional reliability of the proposed framework for HFT designs. Full article

In milling operations, cutters entering and exiting workpiece boundaries cause varying radial immersions and chip thicknesses. This generates aperiodic cutting forces that often induce vibrations and degrade surface quality. To address this, this study aims to accurately predict milling forces and surface profiles during these critical engagement and disengagement phases. An analytical approach was developed to estimate the changing distances between the cutting teeth and workpiece boundaries, enabling the precise calculation of the dynamic chip thickness as the cutter transitions through the material. Based on these dynamic calculations, milling forces and system responses were simulated. Experimental validation demonstrated a strong agreement between the simulated cutting forces, machined surface profiles, and real-world results. Notably, findings revealed that even cutting parameters deemed stable by traditional stability lobes can still trigger vibrations during these boundary transitions. Consequently, a novel parameter selection strategy is proposed to effectively prevent these transient vibrations, significantly enhancing the final surface finish. Ultimately, this comprehensive modelling framework provides a deeper understanding of the system dynamics throughout the entire milling process, offering high relevance for broader applications, such as optimising energy consumption, predicting tool wear, and improving machining parameter optimisation. Full article

While double-layer insulation structures are widely adopted, their thermal performance is critically dependent on the thermophysical behavior of the interstitial air cavity, a variable often oversimplified in current design practices. This article moves beyond generic material descriptions to investigate the specific mechanism of heat transfer transition within sealed air gaps sandwiched between graphite polystyrene boards. The innovation of this experiment lies in the rigorous isolation of air gap thickness as the primary independent variable within a 1 × 1 × 1 m closed building model, instrumented with high-precision GPRS temperature and humidity sensors to capture real-time thermal gradients under the authentic climate conditions of Anyang, Henan. The results demonstrate a non-monotonic relationship between gap thickness and effective thermal resistance, governed by the competition between molecular conduction and buoyancy-driven natural convection. Specifically, the data validates that a 20 mm air gap represents the statistically significant optimum, thereby maximizing insulation efficiency while minimizing radiative heat loss. Using this optimized structure reduces steady-state heat flux compared to monolithic equivalents and aligns with the energy conservation target. Unlike previous studies limited by simulation assumptions or short-term testing, this research provides empirically verified, long-term field data that bridges the gap between theoretical fluid dynamics and practical building envelope engineering. These findings offer a robust, physics-based reference for optimizing double-layer insulation systems in the Central Plains, directly supporting the low-carbon retrofitting of existing building stocks. Full article

Developing functional foods that address both oxidative stress and physiological challenges like dysphagia is a critical frontier in personalized nutrition. This study investigates the multi-component synergy of Fu Ling Yin Zi (FLYZ), a traditional dietary therapy, and translates its functional properties into a 3D-printed dysphagia-friendly food. Using response surface methodology, the optimal FLYZ formulation was established at a 5:1:5 ratio of Poria cocos (Schw.) Wolf., Amygdalus communis Vas, and Citrus reticulata. Network pharmacology and molecular docking suggested that FLYZ’s active compounds (e.g., nobiletin, stigmasterol, tangeretin, l-SPD, glabridin, estrone) may mitigate oxidative stress via multiple targets (PTGS2, AKT1, TNF, ESR1, MMP9, and MAOA), with pathway analysis pointing to a potential role of the AKT1/GSK3β/HIF-1α axis. Subsequent in vitro cellular assays demonstrated that FLYZ enhanced antioxidant enzyme activities, reduced intracellular ROS, and modulated the expression of associated genes, supporting a potential link to this pathway. To actualize these functional benefits for patients with swallowing difficulties, a novel 3D-printing ink incorporating FLYZ and walnut oil within a hydrogel matrix (3% xanthan gum, 3% pectin, 1.5% carrageenan) was developed. The printed constructs exhibited excellent shape fidelity and, based on standardized IDDSI fork and spoon tests, were categorized as level 4 (pureed/extremely thick). Furthermore, a simulated in vitro digestion model showed that the colloidal network significantly protected FLYZ’s polyphenols and flavonoids, markedly improving their bioaccessibility and post-digestion antioxidant capacity. Collectively, this work establishes an integrated approach that combines predictive molecular profiling with advanced 3D food printing, thereby supporting the development of future foods tailored for personalized nutrition. Full article

Mo–Re alloys serve as critical structural components for high-temperature nuclear reactors, and their irradiation degradation is closely related to the evolution of vacancy-type defects. In this study, heavy-ion and He-ion irradiations were performed under RT to introduce an average displacement damage of 3.5 dpa within the 1 μm-thick surface layer of Mo–Re alloys with Re content up to 47 wt.%. PALS, SPB-DBS and CDB techniques were employed to characterize the size, concentration, depth distribution and local chemical environment of irradiation-induced vacancy-type defects. The results demonstrate that the longer lifetime component of irradiated Mo–Re alloys ranged from 262 to 280 ps, corresponding to medium-sized vacancy clusters. The S parameter of all specimens increased significantly from approximately 0.42 to 0.50, with negligible differences (<0.01) among various Mo–Re alloys. No distinct characteristic peak of Re was observed near 17 × 10⁻³ m₀c at the vacancy sites, which was inconsistent with simulation predictions. Mo–Re alloys exhibit similar vacancy-type defect features to pure Mo, implying weak interactions between Re solute atoms and vacancy-type defects under RT irradiation. Full article