Search Results (823)

The combination of scaffold materials and bioactive factors is a promising strategy for promoting bone defect repair in tissue engineering. Previous studies have shown that osteoglycin (OGN) is highly expressed in the bone repair process using deer antler as an animal model of bone defects. It suggests that OGN may be a key active component involved in the bone repair process. The aim of this study was to investigate whether deer OGN (dOGN) could effectively promote bone regeneration. We successfully expressed dOGN using the E. coli pET30a system and evaluated its biological activity through cell proliferation and migration assays. At a concentration of 5 μg/mL, dOGN significantly promoted cell proliferation and migration. We then incorporated dOGN onto decellularized antler cancellous bone (DACB) scaffolds and assessed their osteogenic potential both in vitro and in vivo. The results indicated that dOGN loading enhanced cell proliferation, adhesion, and osteogenic activity. In vivo experiments confirmed that the dOGN-DACB scaffold significantly improved bone regeneration compared to DACB alone. This study demonstrates that dOGN-loaded DACB scaffolds hold great potential for clinical applications in treating critical-sized bone defects by mimicking the rapid regenerative properties of deer antlers. Full article

Quinoa protein isolate (QPI) and sodium alginate (SA) have excellent biocompatibility and functional properties, making them promising candidates for food-grade delivery systems. In this study, we developed, for the first time, a QPI/SA complex-stabilized Pickering emulsion for curcumin encapsulation. The coacervation behavior of QPI and SA was investigated from pH 1.6 to 7.5, and the structural and interfacial characteristics of the complexes were analyzed using zeta potential measurements, Fourier-transform infrared spectroscopy, scanning electron microscopy, and contact angle analysis. The results showed that the formation of QPI/SA complexes was primarily driven by electrostatic interactions, hydrogen bonding, and hydrophobic interactions, with enhanced amphiphilicity observed under optimal conditions (QPI/SA = 5:1, pH 5). The QPI/SA-stabilized Pickering emulsions demonstrated excellent emulsification performance and storage stability, maintaining an emulsification index above 90% after 7 d when prepared with 60% oil phase. In vitro digestion studies revealed stage-specific curcumin release, with sustained release in simulated gastric fluid (21.13%) and enhanced release in intestinal fluid (88.21%). Cytotoxicity assays using HeLa cells confirmed the biocompatibility of QPI/SA complexes (≤500 μg/mL), while curcumin-loaded emulsions exhibited dose-dependent anticancer activity. These findings suggest that QPI/SA holds significant potential for applications in functional foods and oral delivery systems. Full article

Research on reliability control for enhancing power systems under random loads holds significant and undeniable importance in maintaining system stability, performance, and safety. The primary challenge lies in determining the reliability index while optimizing system parameters. To effectively address this challenge, we developed a novel intelligent algorithm and conducted an optimal reliability assessment for a Negative Stiffness Device (NSD) seismic isolation structure incorporating fractional-order damping. This algorithm combines the Gaussian Radial Basis Function Neural Network (GRBFNN) with the Particle Swarm Optimization (PSO) algorithm. It takes the reliability function with unknown parameters as the objective function, while using the Backward Kolmogorov (BK) equation, which governs the reliability function and is accompanied by boundary and initial conditions, as the constraint condition. During the operation of this algorithm, the neural network is employed to solve the BK equation, thereby deriving the fitness function in each iteration of the PSO algorithm. Then the PSO algorithm is utilized to obtain the optimal parameters. The unique advantage of this algorithm is its ability to simultaneously achieve the optimization of implicit objectives and the solution of time-dependent BK equations.To evaluate the performance of the proposed algorithm, this study compared it with the algorithm combines the GRBFNN with Genetic Algorithm (GA-GRBFNN)across multiple dimensions, including performance and operational efficiency. The effectiveness of the proposed algorithm has been validated through numerical comparisons and Monte Carlo simulations. The control strategy presented in this paper provides a solid theoretical foundation for improving the reliability performance of mechanical engineering systems and demonstrates significant potential for practical applications. Full article

In order to address vibration and noise challenges in modern industry while satisfying the lightweighting requirements for aerospace and transportation applications, the development of polymer elastomers integrating both lightweight and high-damping properties holds substantial significance. This study developed polyurethane (PU) with optimized damping and mechanical properties at room temperature through monomer composition optimization. Hollow glass microspheres (HGMs) were introduced into the PU matrix to increase stiffness and reduce density, though this resulted in decreased tensile strength (Rm) and loss factor (tanδ). To further improve mechanical and damping properties, we applied a carbon coating to the surface of the HGMs to optimize the interface between the HGMs and the PU matrix, and systematically investigated the energy dissipation and load-bearing behavior of PU composites. The effect of enhanced interface damping of HGM@C/PU resulted in broadening of the effective damping temperature range (tanδ ≥ 0.3) and higher maximum loss factor (tanδ_max) compared to HGM/PU at equivalent filler loading. The tensile and dynamic properties significantly improved due to optimized interfacial adhesion. In PU composites reinforced with 10 wt% HGM and HGM@C, a 46.8% improvement in Rm and 11.0% improvement in tanδ_max occurred after carbon coating. According to acoustic testing, average transmission loss of HGM/PU and HGM@C/PU with the same filler content showed a difference of 0.3–0.5 dB in 500–6300 Hz, confirming that the hollow structure of the HGMs was preserved during carbon coating. Full article

The lateral vibration of propulsion shafting is a critical factor affecting the acoustic stealth performance of underwater vehicles. As the main vibration isolation component in transmitting vibrational energy, the damping efficiency of the propulsion shafting support system (PSSS) holds particular significance. This study investigates the dynamic characteristics of the PSSS with the integral squeeze film damper (ISFD). A dynamic model of ISFD–PSSS is developed to systematically analyze the effects of shaft speed and external load on its dynamic behavior. Three test bearings (conventional, 1S, and 3S structure) are designed and manufactured to study the influence of damping structure layout scheme, damping fluid viscosity, unbalanced load, and shaft speed on the vibration reduction ability of ISFD–PSSS through axis orbit and vibration velocity. The results show that the damping effects of ISFD–PSSS are observed across all test conditions, presenting distinct nonlinear patterns. Suppression effectiveness is more pronounced in the vertical direction compared to the horizontal direction. The 3S structure bearing has better vibration reduction and structural stability than other schemes. The research results provide a reference for the vibration control method of rotating machinery. Full article

A dual-polarization energy selective surface (ESS) with low insertion loss (IL) and high shielding effectiveness (SE) based on a dual-resonant equivalent circuit topology was proposed for high-intensity radiation field (HIRF) protection in this paper. The design principle was elucidated through an equivalent circuit model and translated into a physical ESS implementation. It consists of two resonant rings, vertically arranged and loaded with diodes, along with two lumped capacitors. Simulation and measurement results demonstrate that the IL is less than 3 dB when in the OFF state in a working frequency band, and the SE exceeds 20 dB when in the ON state. Moreover, the ESS’s dual-polarization, low cost, and easy-to-design characteristics hold great promise for broad applications in protecting communication and radar systems in complex electromagnetic environments. Full article

The use of 3D printing holds significant promise to transform the construction industry by enabling automation and customization, although key challenges remain—particularly the control of fresh-state rheology. This study presents a novel formulation that combines potassium-rich biomass fly ash (BFAK) with an air-entraining plasticizer (APA) to optimize the rheological behavior, hydration kinetics, and structural performance of mortars tailored for extrusion-based 3D printing. The results demonstrate that BFAK enhances the yield stress and thixotropy increases, contributing to improved structural stability after extrusion. In parallel, the APA adjusts the viscosity and facilitates material flow through the nozzle. Isothermal calorimetry reveals that BFAK modifies the hydration kinetics, increasing the intensity and delaying the occurrence of the main hydration peak due to the formation of secondary sulfate phases such as Aphthitalite [(K₃Na(SO₄)₂)]. This behavior leads to an extended setting time, which can be modulated by APA to ensure a controlled processing window. Flowability tests show that BFAK reduces the spread diameter, improving cohesion without causing excessive dispersion. Calibration cylinder tests confirm that the formulation with 1.5% APA and 2% BFAK achieves the maximum printable height (35 cm), reflecting superior buildability and load-bearing capacity. These findings underscore the novelty of combining BFAK and APA as a strategy to overcome current rheological limitations in digital construction. The synergistic effect between both additives provides tailored fresh-state properties and structural reliability, advancing the development of a sustainable SMC and printable cementitious materials. Full article

Initially, the effects of sheet combinations for joining two sheets, including 780 MPa steel and A5052 aluminum alloy sheets, on the joined cross-sectional shapes of the sheets in a clinch-bonding process and the tension-shear load of joined sheets were investigated. The effect of an adhesive on the amounts of the interlock and the minimum thickness in the upper sheet was not large, whereas the effect of the sheet combination was observed. Subsequently, for joining the upper 980 MPa ultra-high-strength steel and lower aluminum alloy sheets in the clinch-bonding process, the effects of the die shape, punch velocity, and sheet holding force on the joinability were investigated. As a result, defect-free conditions were narrowly constrained. Finally, a method that involved controlling material flow using an adhesive with fine particles to increase friction between the sheets was introduced. The upper 980 MPa steel and lower aluminum alloy sheets were successfully joined using this approach. Full article

Barite, a mineral composed of barium sulphate, holds global significance due to its wide range of industrial applications. It plays a crucial role as a weighting agent in drilling fluids for the oil and gas industry, in radiation shielding, and as a filler in paints and plastics. Although there are significant deposits of the mineral in commercial quantities in Nigeria, the use of barite of Nigerian origin has been low in the industry due to challenges that require further research and development. This research employed nanoindentation experiments using a model Ti950 Tribo indenter instrument equipped with a diamond Berkovich tip. Using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), we gained information about the structure and elements in the samples. The load–displacement curves were examined to determine the hardness and reduced elastic modulus of the barite samples. The SEM images showed that barite grains have a typical grainy shape, with clear splitting lines and sizes. XRD and EDX analysis confirmed that the main components are chlorite, albite, barium, and oxygen, along with small impurities like silicon and calcium from quartz and calcite. The average hardness of the IB3 and IB4 samples was 1.88 GPa and 1.18 GPa, respectively, meaning that the IB3 sample will need more energy to crush because its hardness is within the usual barite hardness range of 1.7 GPa to 2.0 GPa. The findings suggest further beneficiation processes to enhance the material’s suitability for drilling and other applications. Full article

Objectives: Sialic acid (SA), a naturally occurring compound abundantly found in birds’ nests, holds immense promise for skincare applications owing to its remarkable biological properties. However, its low bioavailability, poor stability, and limited skin permeability have constrained its widespread application. Methods: To overcome these challenges, SA was encapsulated within nanoliposomes (NLPs) by the high-pressure homogenization technique to develop an advanced and efficient transdermal drug delivery system. The skincare capabilities of this novel system were comprehensively evaluated across multiple experimental platforms, including in vitro cell assays, 3D skin models, in vivo zebrafish studies, and clinical human trials. Results: The SA-loaded NLPs (SA-NLPs) substantially improved the transdermal penetration and retention of SA, facilitating enhanced cellular uptake and cell proliferation. Compared to free SA, SA-NLPs demonstrated a 246.98% increase in skin retention and 1.8-fold greater cellular uptake in HDF cells. Moreover, SA-NLPs protected cells from oxidative stress-induced damage, stimulated collagen synthesis, and effectively suppressed the secretion of matrix metalloproteinases, tyrosinase activity, and melanin production. Additionally, zebrafish-based assays provided in vivo evidence of the skincare efficacy of SA-NLPs. Notably, clinical evaluations demonstrated that a 56-day application of the SA-NLPs-containing cream resulted in a 4.20% increase in L*, 7.87% decrease in b*, 8.45% decrease in TEWL, and 4.01% reduction in wrinkle length, indicating its superior brightening, barrier-repair, and anti-aging effects. Conclusions: This multi-level, systematic investigation strongly suggests that SA-NLPs represent a highly promising transdermal delivery strategy, capable of significantly enhancing the anti-aging, barrier-repair, and skin-brightening properties of SA, thus opening new avenues for its application in the fields of dermatology and cosmeceuticals. Full article

Underground pumped storage hydropower stations (UPSH) are of great significance for energy structure adjustment, and coal mine underground reservoirs are an integral part of UPSH. This study investigates the fracture mechanics behavior of coal in mine water immersion environments with varying loading rates and layer direction. Three types of samples were analyzed: Crack-arrester, Crack-splitter, and Crack-divider types. The immersion duration extended up to 120 days. The results indicate that, after immersion in mine water for 120 days, the fracture toughness (K_IC), fracture modulus (E_S), and absorbed energy (U_T) of coal decreased by 60.87%, 53.38%, and 63.21%, respectively, compared to the unsaturated coal samples. An immersion period of 30 days significantly weakens the mechanical properties of coal fractures. The K_IC, E_S, and U_T of coal demonstrate a positive correlation with loading rate, primarily influenced by the duration of coal damage. At the same loading rate, the order of fracture toughness among the three coal types is as follows: Crack-divider > Crack-arrester > Crack-splitter. This hierarchy is determined by the properties of the coal matrix and bedding planes, as well as the mechanical structures composed of them. This study holds significant implications for the safe construction and operational design of underground water reservoirs in coal mines. Full article

To address the limitations of conventional single-track rail systems in challenging hilly and mountainous terrains, which are ill-suited for transporting heavy agricultural machinery, there is a critical need to develop a specialized the double-track rail transportation system optimized for orchard equipment. Recognizing this requirement, our research team designed and implemented a double-track rail transportation system. In this innovative system, the rail functions as the pivotal component, with its structural properties significantly impacting the machine’s overall stability and operational performance. In this study, resistance strain gauges were employed to analyze the stress–strain distribution of the track under a full load of 750 kg, a critical factor in the system’s design. To further investigate the structural performance of the double-track rail, the impact hammer method was utilized in conjunction with triaxial acceleration sensors to conduct experimental modal analysis (EMA) under actual support conditions. By integrating the Eigensystem Realization Algorithm (ERA), the first 20 natural modes and their corresponding parameters were successfully identified with high precision. A comparative analysis between finite element simulation results and experimental measurements was performed, revealing the double-track rail’s inherent vibration characteristics under constrained modal conditions versus actual boundary constraints. These valuable findings serve as a theoretical foundation for the dynamic optimization of rail structures and the mitigation of resonance issues. The advancement of hilly and mountainous rail transportation systems holds significant promise for enhancing productivity and transportation efficiency in agricultural operations. Full article

The encapsulation of hydrophobic substances remains a significant challenge due to limitations such as low loading efficiency, leakage, and poor distribution within microcapsules. This study introduces a novel strategy utilizing colloidosomes assembled from polyelectrolyte microcapsules (PMCs). PMCs were fabricated via layer-by-layer (LbL) assembly on manganese carbonate (MnCO₃) or calcium carbonate (CaCO₃) cores, followed by core dissolution. A solvent gradient replacement method was employed to substitute the internal aqueous phase of PMCs with kerosene, enabling the formation of colloidosomes through self-assembly upon resuspension in water. Comparative analysis revealed that MnCO₃-based PMCs with smaller diameters (2.5–3 µm vs. 4.5–5.5 µm for CaCO₃) exhibited 3.5-fold greater stability, attributed to enhanced inter-capsule interactions via electrostatic and hydrophobic forces. Confocal microscopy confirmed the structural integrity of colloidosomes, featuring a liquid kerosene core encapsulated within a PMC shell. Temporal stability studies indicated structural degradation within 30 min, though 5% of colloidosomes retained integrity post-water evaporation. PMC-based colloidosomes exhibit significant application potential due to their integration of colloidosome functionality with PMC-derived structural features—semi-permeability, tunable shell thickness/composition, and stimuli-responsive behavior—enabling their adaptability to diverse technological and biomedical contexts. This innovation holds promise for applications in drug delivery, agrochemicals, and environmental technologies, where controlled release and stability are critical. The findings highlight the role of core material selection and solvent engineering in optimizing colloidosome performance, paving the way for advanced encapsulation systems. Full article

Tourist satisfaction models typically assume that service performance dimensions carry the same weight for all travelers. Drawing on Bourdieu, we reconceptualize age, gender, and region of origin as demographic capital, durable resources that mediate how visitors decode service cues. Using a SERVPERF-based survey of 407 international travelers departing Quito (Ecuador), we test measurement invariance across six sociodemographic strata with multi-group confirmatory factor analysis. The four-factor SERVPERF core (Access, Lodging, Extra-hotel Services, Attractions) holds, yet partial metric invariance emerges: specific loadings flex with demographic capital. Gen-Z travelers penalize transport reliability and safety; female visitors reward cleanliness and empathy; and Latin American guests are the most critical of basic organization. These patterns expose a boundary condition for universalistic satisfaction models and elevate demographic capital from a descriptive tag to a structuring construct. Managerially, we translate the findings into segment-sensitive levers, visible security for youth and regional markets, gender-responsive facility upgrades, and dual eco-luxury versus digital-detox bundles for long-haul segments. By demonstrating when and how SERVPERF fractures across sociodemographic lines, this study intervenes in three theoretical conversations: (1) capital-based readings of consumption, (2) the search for boundary conditions in service-quality measurement, and (3) the shift from segmentation to capital-sensitive interpretation in emerging markets. The results position Ecuador as a critical case and provide a template for destinations facing similar performance–perception mismatches in the Global South. Full article

LiDAR-assisted wind turbine control holds strong potential for reducing structural loads and improving rotor speed regulation, thereby contributing to more sustainable wind energy generation. However, key research gaps remain: (i) the practical limitations of commercially available fixed beam LiDARs for large turbines, and (ii) the performance assessment of commonly used LiDAR assisted feedforward control methods. This study addresses these gaps by (i) analysing how the coherence of LiDAR estimated rotor effective wind speed is influenced by the number of beams, measurement locations, and turbulence box resolution, and (ii) comparing two established control strategies. Numerical simulations show that applying a low cut-off frequency in the low-pass filter can impair preview time compensation. This is particularly critical for large turbines, where reduced coherence due to fewer beams undermines the effectiveness of LiDAR assisted control compared to the smaller turbines. The subsequent evaluation of control strategies shows that the Schlipf method offers greater robustness and consistent load reduction, regardless of the feedback control design. In contrast, the Bossanyi method, which uses the current blade pitch measurements, performs well when paired with carefully tuned baseline controllers. However, using the actual pitch angle in the feedforward pitch rate calculation can lead to increased excitation at certain frequencies, particularly if the feedback controller is not well tuned to avoid dynamics in those ranges. Full article