Search Results (330)

Background/Objectives: Assessing the bioavailability of nutrients and bioactive compounds in vitro commonly relies on coupling standardized gastrointestinal digestion models with intestinal epithelial cell systems. However, digests produced using static digestion protocols such as INFOGEST often impair epithelial barrier integrity, limiting their direct application to intestinal models and reducing reproducibility across studies. Methods: This work systematically compared five commonly used digest conditioning strategies, including acidification, centrifugation, rapid freezing, and ultrafiltration using 10 kDa and 3 kDa molecular weight cut-off membranes, to identify the approach that best preserves intestinal epithelial viability and barrier function while enabling exposure at physiologically relevant concentrations. INFOGEST digests of yogurt were initially evaluated, followed by validation using biscuit and canned mackerel digests. Cell viability and monolayer integrity were assessed in differentiated Caco-2 cells using MTT assay and transepithelial electrical resistance (TEER) measurements. Results: Among the tested approaches, ultrafiltration using 3 kDa membranes consistently preserved epithelial viability and barrier integrity at a 1:10 dilution across all food matrices, whereas other conditioning methods failed to maintain TEER despite acceptable cell viability. At lower dilutions, food-dependent effects emerged, highlighting the importance of matrix-specific evaluation. Conclusions: These findings identify 3 kDa ultrafiltration as an effective and minimally invasive strategy to improve the compatibility of INFOGEST digests with intestinal cell models. By enabling reproducible exposure conditions that preserve epithelial integrity, this approach supports more reliable in vitro assessment of nutrient bioavailability and contributes to methodological standardization in nutrition research. Full article

This study employed a combined approach of computational fluid dynamics (CFD), numerical simulations, and wind tunnel tests to investigate droplet drift characteristics and develop prediction models in order to address the issues of low pesticide utilization rates and high drift risk, associated with droplet drift during agricultural unmanned aerial vehicle (UAV) spraying, as well as the unreliable results of field experiments. Firstly, a numerical model of the rotor wind field was established using the multiple reference frame (MRF) method, while the realizable k-ε turbulence model was employed to analyze the flow field. The model’s reliability was verified through wind field tests. Next, the Euler–Lagrange method was used to couple the wind field with droplet movement. The drift characteristics of two flat-fan nozzles (FP90-02 and F80-02) were then compared and analyzed. The results showed that the relative error between the simulated and wind tunnel test values was within 20%. Centrifugal nozzle experiments were carried out using single-factor and orthogonal designs to analyze the effects of flight height, rotor wind speed, flight speed, and droplet size on drift. The priority order of influence was found to be “rotor wind speed > flight height > flight speed”, while droplet size (D_V50 = 100–300 µm) was found to have no significant effect. Based on the simulation data, a multiple linear regression drift prediction model was constructed with a goodness of fit R² value of 0.9704. Under the verification condition, the relative error between the predicted and simulated values was approximately 10%. These results can provide a theoretical basis and practical guidance for assessing drift risk and optimizing operational parameters for agricultural UAVs. Full article

Long-term settlement of dredger fill presents substantial challenges to infrastructure stability, particularly in coastal areas such as Tianjin Nangang, where liquefied natural gas (LNG) pipelines are vulnerable to deformation caused by differential settlements. This study investigates the geological properties and long-term settlement characteristics of dredger fill in the Tianjin Nangang coastal zone and develops a simplified predictive model for long-term settlement. Comprehensive laboratory analyses, including field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and mercury intrusion porosimetry (MIP), revealed a porous, flaky microstructure dominated by quartz and calcite, with mesopores (0.03–0.8 µm) constituting over 80% of total pore volume. A centrifuge modelling test conducted at 70 g acceleration simulated accelerated settlement behavior, demonstrating that approximately 70% of settlements occured within the initial year. The study proposes an enhanced hyperbolic model for long-term settlement prediction, which shows excellent correlation with experimental results. The findings underscore the high compressibility and low shear strength of dredger fill, highlighting the necessity for specific mitigation measures to ensure infrastructure integrity. This research establishes a simplified yet reliable methodology for settlement estimation, providing valuable practical guidance for coastal land reclamation projects. Full article

An innovative methodology based on a centrifugation-assisted ultrafiltration process (CUF) has been investigated as a suitable methodology to enhance the bioavailability of phenolic compounds with antioxidant activity from winery by-products. For this purpose, seed (GSE) and stem (STE) extracts obtained by pressurized liquid extraction were processed by applying CUF methodology, generating a seed and stem permeate (PGSE and PSTE, respectively). The evaluated methodology allowed for the removal of the polymeric proanthocyanidin fraction. Thus, PGSE and PSTE resulted in a lower number of phenolic compounds and antioxidant activity compared to GSE and STE extracts. However, meanwhile, the low-molecular-weight fraction showed a close trend in its phenolic profile composition, the quantity of the compounds was increased because of a concentration effect in the permeates. Phenolic compounds bioavailability was conducted through an in vitro static digestion method followed by in vitro intestinal absorption using a Caco-2 cell monolayer model. PGSE and PSTE bioaccessibility was greater than STE and GSE because of an intense loss of the polymeric fraction during the digestion process. In addition, higher amounts of total phenolic compounds, as well as low-molecular-weight phenolics, were determined in the PGSE and PSTE bioaccessible fractions. Furthermore, higher antioxidant and total phenolic compounds were detected in the bioavailable fraction after in vitro intestinal absorption assays for the permeates. Hence, CUF methodology resulted as a suitable and effective technique to enhance the phenolic extracts’ bioavailability, although the phenolic matrix effect should be tested. Full article

Punch-through accidents pose a significant risk during the positioning of jack-up rigs. To mitigate this hazard, accurate prediction of the peak penetration resistance of spudcan foundations is essential for developing safe operational plans. Advances in artificial intelligence have spurred the widespread application of machine learning (ML) to geotechnical engineering. To evaluate the prediction effect of different algorithm frameworks on the peak resistance of spudcans, this study evaluates the feasibility of ML and multi-view learning (MVL) methods using existing centrifuge test data. Six ML models—Random Forest, Support Vector Machine (with Gauss, second-degree, and third-degree polynomial kernels), Multiple Linear Regression, and Neural Networks—alongside a Ridge Regression-based MVL method are employed. The performance of these models is rigorously assessed through training and testing across various working conditions. The results indicate that well-trained ML and MVL models achieve accurate predictions for both sand-over-clay and three-layer clay strata. For the sand-over-clay stratum, the mean relative error (MRE) across the 58-case dataset is approximately 15%. The Neural Network and MVL method demonstrate the highest accuracy. This study provides a viable and effective empirical solution for predicting spudcan peak resistance and offers practical guidance for algorithm selection in different stratigraphic conditions, ultimately supporting enhanced safety planning for jack-up rig operations. Full article

This review aims to provide a complete and comprehensive state of the art of the SCOSSA computer code, which is a one-dimensional nonlinear computer code used for the analysis of seismic site response and soil instability. Indeed, among the effects of earthquakes, the activation of landslides and liquefaction constitute two of the predominant causes of vulnerability in the physical and built environment. The SCOSSA computer code (Seismic Code for Stick–Slip Analysis) was initially developed to evaluate the permanent displacements of simplified slopes using a coupled model, and introduced several improvements with respect to the past, namely, the formulation for solving the dynamic equilibrium equations incorporates the capability for automated detection of the critical sliding surface; an up-to-date constitutive model to represent hysteretic material behavior and a stable iterative algorithm to support the solution of the system in terms of kinematic variables. To address liquefaction-induced failure, a simplified pore water pressure generation model was subsequently developed and integrated into the code, coupled with one-dimensional consolidation theory. This review retraces the main features, developments, and applications of the computer code from the origin to the present version. Full article

This study quantifies vertical earth pressure on the roofs of box culverts under high fills in valley terrain using centrifuge model tests with expanded polystyrene (EPS) geofoam for load mitigation. We compare buried-type culverts with valley-terrain high-fill culverts and isolate the effects of the EPS installation height and panel thickness on the roof pressure and the associated concentration factor. The analysis of fill settlement elucidates the terrain-dependent load reduction mechanism and the efficacy of EPS panels. The results show that the roof pressure increases with EPS installation height but decreases and then plateaus once the panel thickness exceeds 75 cm; the load reduction benefit weakens when the installation height exceeds 2 m. Optimal performance is achieved with panels installed at 2 m and with a 75 cm thickness, which lowers applied loads while maintaining structural stability. These findings clarify soil–structure interactions in complex topography and provide practical guidance for deploying EPS in high-fill valley projects. Full article

An efficient and reliable heat dissipation system is essential for the safe and stable operation of high-power water-cooled couplers. However, thermal analysis methods accounting for the centrifugal effects on coolant flow remain limited. This paper presents a high-accuracy equivalent thermal network model (ETNM) for analyzing the temperature distribution in water-cooled permanent magnet couplers (WPMCs), based on fluid–structure interaction and rotational centrifugal flow-field inversion. First, the ETNM is established based on key assumptions. Subsequently, an eddy current loss calculation method based on permanent magnet mapping is proposed to accurately determine the heat source distribution. The convective heat transfer coefficient of the coolant is then precisely derived by inverting the flow field obtained from fluid–structure coupling simulations under rotational centrifugal conditions. Finally, the model is applied for temperature analysis, and its accuracy is verified through both finite element simulations and experimental tests. The calculated results show errors of only 3.2% compared to numerical simulation and 5.6% compared to experimental data, indicating strong agreement of the proposed thermal analysis method. The accuracy of copper conductor (CC) temperature prediction is improved by 32.73%, and that of permanent magnet (PM) prediction by 33.33%. Furthermore, this method enables accurate estimation of individual component temperatures, effectively preventing operational failures such as PM demagnetization, CC softening, and severe vibrations caused by overheating. Full article

This study presents an integrated experimental–modeling investigation of the thermal behavior of a multistage centrifugal refrigerant pump in solar ejector refrigeration systems (SERS). A temperature-rise prediction model is formulated strictly from energy conservation with viscous dissipation and validated on a closed-loop test rig under variable flow rates, inlet pressures, and operating frequencies. Experiments show that the outlet temperature rise (ΔT) decays approximately exponentially with increasing flow rate, while higher operating frequency intensifies viscous-dissipation heating. The pressure difference (Δp) increases with both flow rate and frequency, whereas the overall efficiency (η) exhibits a parabolic trend, peaking at 32.6% at 37.5 Hz. The model achieves high predictive accuracy, with errors within ±0.4 °C at 25–37.5 Hz and about ±1.1 °C at 50 Hz. By constructing Δp–Q–f operating maps and coupling them with cavitation-risk analysis, safe and optimal operating zones (“best zone” and “caution zone”) are identified. These results provide quantitative guidance for pump thermal management, frequency scheduling, and system integration, enabling energy-efficient and reliable operation of solar-driven ejector refrigeration systems. Full article

To address the industry pain points of high seed breakage rate and uncontrollable miss-filling rate, multiple-filling rate in traditional rapeseed roller-type precision centralized seed metering devices—while breaking the adaptation limitation of existing empirical hole designs for different small-particle-size crops—this study innovatively proposes a hole optimization scheme based on the Bezier curve and develops a roller-type precision centralized seed metering device suitable for rapeseed and small-particle-size crops. First, combined with the physical properties of rapeseed seeds (particle size 1.5~2.5 mm, high sphericity, strong fluidity) and agronomic requirements for precision seeding, a multi-mechanical coupling model for seed filling and dropping (synergistic effect of gravity–centrifugal force–air blowing force) was established. The regulatory mechanism of hole geometric parameters (wrap angle, width, height) on seeding performance was clarified, and the enhancement mechanism of the Bezier curve’s curvature continuity on seed movement stability was revealed from the theoretical level. On this basis, a three-factor quadratic orthogonal combination experiment of hole wrap angle, width, and height was conducted using EDEM discrete element software. The optimal hole parameter combination was obtained through multi-objective optimization (minimizing miss-filling rate, multiple-filling rate and maximizing seed-filling qualification rate): wrap angle 2.271° (error ± 0.2°), width 3.407 mm (error ± 0.1 mm), and height 2.254 mm (error ± 0.02 mm). Simulation results showed that under this parameter combination, the seed-filling qualification rate reached 99.122%, with the miss-filling rate and multiple-filling rate as low as 0.448% and 0.416%, respectively. Further bench test verification indicated that when the roller speed was in the range of 10~30 r/min, the seed breakage rate was consistently below 0.5%, and the seed-filling qualification rate remained above 94%. Among them, the comprehensive seeding performance was optimal at a speed of 15 r/min, with a miss-seeding rate of 0.65%, a multiple-seeding rate of 2.06%, and a breakage rate of 0.12%, fully meeting the agronomic requirements for rapeseed precision seeding, providing a theoretical basis and engineering reference for the digital and universal design of key components of precision seeders for small-particle-size crops. Full article

A series of centrifuge model tests was performed to investigate the influence of subgrade surcharge loading on adjacent bridge pile foundations in soft soils, based on the Mingu Road project in Zhongshan City, China. Four surcharge distances (1D, 2D, 3D, and 4D, where D is the pile diameter) were examined to clarify the spatial–temporal evolution of pile–soil interaction. The results show that horizontal displacement, bending moment, and lateral soil resistance of the pile increase over time, exhibiting significant time-dependent behavior characterized by rapid initial growth followed by stabilization. As the surcharge distance increases, these responses decrease markedly, indicating a strong spatial attenuation effect. The bending moment along the pile depth follows a unimodal pattern with a peak at the soft soil layer. In contrast, the lateral soil resistance exhibits a similar trend of increase and decrease with depth. When the surcharge distance exceeds approximately 4D, the additional influence on the pile response becomes small. This study provides physical evidence and theoretical support for the safe design and construction of bridge pile foundations adjacent to road embankments in areas with soft soil. Full article

The offshore wind industry is expanding from shallow water to deep water. As a cost-effective and efficient anchoring solution, drag embedment anchors have been widely used for mooring floating offshore structures. However, there is currently no well-established method for predicting the installation trajectory and holding capacity of drag anchors in sand. This paper reports an integrated anchor–chain–soil large-deformation finite-element model for simulating the complete installation of drag anchors in sand. The proposed approach restores the effects of anchor chains and detailed structures of the anchor, which is essential for detailed anchor design. Sensitivity analysis is conducted to investigate the convergence of model parameters. The performance of the numerical model is benchmarked against a centrifuge test conducted at the University of Western Australia (UWA), which demonstrates satisfactory accuracy and reliability. Installation simulations are then performed using a popular commercial anchor design in sands of different friction angles. Three characteristic stages during the drag embedment process are identified. The results highlight the significant influence of the soil resistance to the shank on the anchor penetration performance. The large-deformation analysis approach proposed provides a powerful tool for further investigation on drag anchor installation behavior in sand. Full article

A low-cost, dynamic flux chamber optimized for landfill emissions measurement was designed, fabricated, calibrated, and validated for measurements of methane flux ranging from 0 to 150 g/m²-day. A centrifugal blower fan and a flow meter were plumbed in series to draw a bypass flow through the flux chamber. Both ambient and chamber methane concentrations were measured using the arrays of four low-cost metal oxide sensors. Leveraging the sensors’ overlapping sensitivity to changes in methane concentration, temperature, and humidity, multiple linear regressions were trained on laboratory data and combined into a piecewise methane calibration function. An algorithm was developed to select the most useful interaction terms among all sensor responses to optimize the predictors in each model. The piecewise regions for methane measurement were 0–100 ppm, 100–1500 ppm, and 1500–12,000 ppm. The root mean squared errors for each piecewise region were 3.1 ppm, 21 ppm, and 307 ppm, respectively. Controlled quantities of methane were delivered to the flux chamber in a laboratory setting for validation. Measurements yielded good agreement with an RMSE and MBE of 7.3 g m⁻² d⁻¹ and 2.2 g m⁻² d⁻¹, respectively. The flux chamber was tested at a closed landfill to validate its ability to autonomously and continuously operate in the field. Full article

Helical coiled tube (HCT) heat exchangers (HXs) are used in the nuclear industry, particularly in the residual heat removal systems of nuclear power plants (NPPs) and steam generators for small modular reactors. In this study, a single-phase CFD model was developed to investigate non-uniform circumferential distributions in the local wall heat transfer characteristics of a vertical HCT to obtain localized information critical for the safety of NPPs. In a comparison, the predicted circumferential heat transfer characteristics agreed well with the measured data. Governed by centrifugal/gravitational forces, these non-uniform distributions are clearly visible in the results, explaining the test data. We performed additional simulations of the conjugated heat transfer from the hot fluid of the shell side to the cold fluid of the tube side, confirming that the inhomogeneity of circumferential distributions in HCTs is due to the assumption of a constant heat flux boundary condition. Full article

This work deals with the preparation and characterization of TiAlV/ZnAlCu composite materials. The aim is to create a model for biomaterial with good biocompatibility and acceptable mechanical properties. Infiltrating zinc into the reinforcement made of the titanium alloy could significantly improve the osseointegration of the bioimplant made from this material. The investigated reinforcements of three different geometries made from Ti-6Al-4V prepared by the SLM method (selective laser melting) were infiltrated with molten zinc or the Zn-based alloy. Two infiltration approaches were used—suction of the melt using a vacuum pump and centrifugal casting. By these procedures, different infiltration rates were achieved. Furthermore, the mechanical properties of the prepared composite materials were characterized by compression tests. The results were compared with the mechanical properties of the Ti-6Al-4V alloy reinforcement. Full article