Search Results (2,290)

Based on the formula for the sizing agent for basalt fiber, this paper presents a comprehensive study of the effects of lubricants on the properties of sizing agents, basalt fiber, and epoxy resin composite materials. Through testing and analysis of physical and chemical parameters, a new sizing agent with excellent performance was developed. The results demonstrated that the components and proportions of the lubricant significantly affected the physical and chemical parameters of the emulsion, as well as the mechanical properties of the basalt fibers and their epoxy resin composite materials. The lubricant with the combination ratio of 0.70% saturated fatty acid polyoxyethylene ester and 0.30% unsaturated fatty acid polyoxyethylene ester and imidazoline lubricant-I produced basalt fiber with the best mechanical properties. The single fiber tensile strength and yarn breaking strength increased by 18.42% and 12.5%. Furthermore, the lubricant with the combination ratio of 0.70% saturated fatty acid polyoxyethylene ester and 0.30% unsaturated fatty acid polyoxyethylene ester and imidazoline lubricant-III resulted in the best mechanical properties for Epoxy–BFRP composite materials. The tensile strength of the Epoxy–BFRP composite material increased by 13.2%, the tensile modulus increased by 45.2%, and the flexural strength increased by 12.0%. Full article

Due to its good adaptability, the pneumatic conveying feeder has been widely developed and applied in recirculating aquaculture systems (RASs). Its important performances include the integrity of feed pellets and the feeding accuracy. The aim of this study was to design and evaluate a feed distribution device for a small-scale pneumatic conveying feeder. A cylindrical hopper with a feed capacity of 4 kg and a feed distribution device were designed based on theoretical calculations. The motion and force of feed pellets during the distribution process were studied using the discrete element method (DEM) simulation to evaluate the integrity of feed pellets. Additionally, to evaluate feeding accuracy, the effect of discharge disk rotational speed on single feeding quantity was studied using DEM simulations and experimental validations, as well as the effect of the proportion of feed pellets in the hopper. Results showed that the maximum force on feed pellets was 1.25 N during the distribution process. It was inferred that the feed pellets can be distributed without breaking based on their shear strength. When the rotational speed of the discharge disk was set at a maximum of 28 rpm, the relative error of single feeding quantity between simulation and actual experiments was 4.43%, and the single feeding mass was 62.74 g, suggesting an optimal speed. In addition, the average single feeding quantity ranged from 262 to 301 feed pellets at the different proportions of feed pellets in the hopper, and its coefficient of variation was 12.46%, which generally meets the distribution requirements of the small-scale feeder. This study provides a feed distribution device for a small-scale pneumatic conveying feeder and offers references for the relevant analysis of DEM simulation. Full article

To advance seaweed polysaccharide applications in hydrogel wound dressings, five antibacterial composite hydrogels (groups A~E) were synthesized using oxidized κ-carrageenan (OKC), acrylamide (AM), and progressively increasing concentrations of silver-based metal–organic frameworks (Ag-MOFs). Systematic characterization revealed concentration-dependent effects: (1) positive correlations were obtained for the moisture content (MC, maximized at 82.70% in E) and antibacterial efficacy (dose-dependent enhancement); (2) negative impacts were obtained for the swelling ratio (SR, E: 479% vs. A: 808%); and (3) high-dose drawbacks but low-dose benefits in terms of water resistance (WR), tensile strength (TS), elongation at break (EB), and microstructure were obtained. Group B demonstrated optimal Ag-MOFs loading, enhancing TS and EB, while excessive Ag-MOFs loading in C~E significantly degraded them (p < 0.05). Microstructural analysis showed severe 3D spatial damage in D~E. Furthermore, cytocompatibility assessments revealed that all groups maintained a cell viability exceeding 90%, demonstrating excellent biocompatibility. Among them, A~C showed a viability statistically equivalent to the control (p > 0.05) and were significantly higher than D~E (p < 0.05). In conclusion, group B emerged as the optimal Ag-MOFs formulation and exhibited superior WR, enhanced mechanical strength (TS and EB), and potent antibacterial activity while maintaining microstructural integrity and excellent biosafety. This Ag-MOFs/OKC/PAM hydrogel provides dual infection prevention and tissue support, maximizing seaweed polysaccharide benefits with excellent biocompatibility. Full article

Corrosion-resistant coatings are essential for prolonging the lifespan of metal structures, yet conventional formulations often lack sufficient mechanical strength and chemical durability. This study focuses on the development of polyurethane/epoxy hybrid coatings (PUAE) with varying epoxy resin content (5%, 10%, and 15% by weight) to enhance performance. The hybrid films demonstrated improved mechanical properties with increasing epoxy content, including a rise in tensile strength from 39.1 MPa (PUA) to 86.3 MPa (PUAE15) and adhesion from 2.5 MPa to 8.3 MPa. Hardness also increased from 69 Shore A to 98 Shore A, while elongation at break decreased from 158% to 95%, indicating a shift toward a stiffer material. The thermal stability, assessed by TGA, showed higher degradation temperatures, with PUAE15 reaching a maximum decomposition temperature of 390 °C, compared to 320 °C for pure polyurethane. Viscosity at 5 rpm increased from 12.300 mPa·s to 18.563 mPa·s, and the contact angle improved from 105° to 149°, highlighting enhanced hydrophobicity. PUAE15 also displayed superior resistance to solvents and acidic environments. These results affirm that epoxy content significantly influences the structural, mechanical, and corrosion-resistant properties of polyurethane-based coatings, making PUAE15 a promising candidate for advanced anticorrosive applications. Full article

This study aims to investigate the effectiveness of two machine learning methods for the prediction of the mechanical and fracture properties of Cenosphere-reinforced lightweight thermoset polyurethane composites. To evaluate the effectiveness of the models, datasets from our experimental study of composites made of five different volume fractions (0% to 40%) of Cenospheres (hollow Aluminum Silicate particles) in increments of 10% are fabricated. Experiments are conducted to determine the effect of the volume fraction of Cenospheres on Young’s modulus (both in tension and compression), percentage elongation at break, tensile strength, specific tensile strength, and fracture toughness of the composites. Two machine learning models, shallow artificial neural network (ANN) and the non-linear deep neural network (DNN), are employed to predict the above properties. A parametric study was performed for each model and optimized parameters were identified and later used to predict the properties beyond 40% volume fraction of Cenospheres. The predictions of non-linear DNN demonstrated less slope than shallow ANN and, for mass density, the non-linear DNN had unexpected predictions of increasing mass density with the addition of lighter Cenospheres. Hence, a double-hidden-layer DNN is used to predict the mass density beyond 40%, which provides the expected behavior. Full article

In this research work, two distinct types of three-dimensional (3D) capacitors were successfully fabricated, each with its own unique features and advantages. The first type of capacitor is centered around a 3D nanoporous structure. This structure is formed on a nickel substrate through anodic oxidation. After undergoing high-temperature thermal oxidation, a monolithic Ni-NiO-Pt metal–insulator–metal (MIM) capacitor with a nanoporous dielectric architecture is achieved. Structurally, this innovative design brings about several remarkable benefits. Due to the nanoporous structure, it has a significantly increased surface area, which can effectively store more charges. As a result, it exhibits an equivalent capacitance density of 69.95 nF/cm², which is approximately 18 times higher than that of its planar, non-porous counterpart. This high capacitance density enables it to store more electrical energy in a given volume, making it highly suitable for applications where miniaturization and high energy storage in a small space is crucial. The second type of capacitor makes use of Through-Glass Via (TGV) technology. This technology is employed to create an interdigitated blind-via array within a glass substrate, attaining an impressively high aspect ratio of 22.5:1 (with a via diameter of 20 μm and a depth of 450 μm). By integrating atomic layer deposition (ALD), a conformal interdigital electrode structure is realized. Glass, as a key material in this capacitor, has outstanding insulating properties. This characteristic endows the capacitor with a high breakdown field strength exceeding 8.2 MV/cm, corresponding to a withstand voltage of 5000 V. High breakdown field strength and withstand voltage mean that the capacitor can handle high-voltage applications without breaking down easily, which is essential for power-intensive systems like high-voltage power supplies and some high-power pulse-generating equipment. Moreover, due to the low-loss property of glass, the capacitor can achieve an energy conversion efficiency of up to 95%. Such a high energy conversion efficiency ensures that less energy is wasted during the charge–discharge process, which is highly beneficial for energy-saving applications and systems that require high-efficiency energy utilization. Full article

Existing convolutional neural network (CNN) methods primarily depend on first-order feature modeling, which makes it challenging to effectively capture higher-order features in breast cancer histopathological images. Additionally, due to the limitations of the receptive field, CNNs have difficulty capturing long-range dependencies, thereby limiting the integration of global information. To address this, inspired by the strengths of high-order statistical features and extended receptive fields in visual tasks, this study proposes a novel high-order receptive field network (HoRFNet). Specifically, HoRFNet expands the receptive field and improves the model’s contextual awareness of pathological tissue structures by introducing a multi-branch convolutional structure with convolution kernels of varying sizes, along with dilated convolution layers. Additionally, HoRFNet integrates a matrix power normalization strategy in the covariance pooling module to model the global interactions between convolutional features, thereby improving the higher-order representation of complex textures and structural relationships in tissue images. The BreakHis dataset shows that HoRFNet achieves an image level classification accuracy of 99.50% and a patient level classification accuracy of 99.23%, significantly outperforming existing methods and demonstrating its effectiveness. Full article

Objectives: The purpose of this study is to quantitatively evaluate the combined effects of sports massage, blood flow restriction (BFR), and cold therapy on quadriceps recovery in mixed martial arts (MMA) athletes following eccentric exercise, focusing on muscle biomechanical properties, pain, and strength. Methods: This randomized, single-blind clinical trial involved 36 men and women MMA-trained participants, divided into three groups: massage (n = 12) received massage, BFR/cool (n = 12) received combined BFR and cooling, and control (n = 12) received passive rest as a control. The fatigue protocol involved MMA fighters performing five sets of plyometric jumps on a 50 cm box until exhaustion, with 1-min breaks between sets. After that, the massage group received a 20-min massage overall using standardized techniques; BFR/cool underwent a 20-min alternating blood flow restriction (200 mmHg) and cooling treatment with ice bags on the quadriceps; and the final group served as the control group with passive rest and no intervention. Participants were assessed four times—before exercise, immediately after exercise, 24 h post-exercise (after two recovery sessions), and 48 h post-exercise (after four recovery sessions)—for perfusion unit (PU), muscle elasticity, pressure pain threshold (PPT), reactive strength index (RSI), and total quality recovery (TQR). Results: The statistical analysis revealed significant effects of both massage and BFR/cooling interventions across key recovery outcomes, with large effect sizes for time-related changes in RSI (p < 0.0001; η² = 0.87), elasticity (p < 0.0001; η² = 0.84), and PPT (p < 0.0001; η² = 0.66). Notably, post-exercise 48 h values for RSI, elasticity, PU, and TQR were significantly improved in both the massage and BFR/cool groups compared to control (p < 0.05)), while no significant group differences were observed for PPT. Conclusions: The study concludes that both massage and combined blood flow restriction with cooling interventions significantly enhance post-exercise recovery—improving muscle perfusion, elasticity, reactive strength, and perceived recovery—compared to passive rest. Full article

Atomic diffusion additive manufacturing (ADAM) is a specialized extrusion-based metal additive manufacturing (MAM) process where metal parts are produced through a three-stage process of printing, de-binding and sintering. Several scientific facts, such as dimensional error, surface quality, tensile behavior and the internal structure of this process for specific materials for certain conditions, are not well explained in the existing literature. To address these issues, the present manuscript investigates the effect of infill type and shell thickness on 17-4 precipitation-hardened (PH) stainless steels on the dimensional accuracy, surface roughness and mechanical properties of the printed specimens. It was found that the strength (maximum ultimate tensile strength up to 1049.1 MPa) and hardness (290 HRB) of the specimens mainly depend on shell thickness, while infill type plays a relatively minor role. The principle of atomic diffusion may be the reason behind this pattern, as an increase in shell thickness is essentially an increase in the density of material deposited during printing, allowing more fusion during sintering and thus increasing its strength. The two different infill types (triangular and gyroid) contribute towards minimal changes, although it should be noted that triangular specimens exhibited greater ultimate tensile strength, whereas the gyroid had slightly longer elongation at break. Dimensional accuracy and surface roughness for all the specimens remain reasonably consistent. The cross-section of the tensile tested specimens revealed significant pores in the microstructure that could contribute to a reduction in the mechanical properties of the specimens. Full article

Food contact polymers require thermochromic pigments to provide temperature-sensitive visual cues for consumer safety and product integrity. However, their susceptibility to ultraviolet (UV) degradation limits long-term application. This study investigates the UV resistance of food-grade thermochromic polypropylene blends under simulated indoor and outdoor UV exposure for 500 and 1000 h. Visual properties, colorimetric (CIE L*a*b*) measurements, mechanical testing (tensile and impact), and mass variation analysis were performed to assess photostability and material integrity. Exposure to UV led to progressive discoloration (ΔE*_ab up to 34.07) and significant mechanical deterioration. Tensile strain at break decreased by 48.67%, and notched impact strength dropped by 44.15% after 1000 h of UV exposure. No measurable mass loss occurred, indicating degradation was confined to surface-level oxidation rather than bulk material erosion or leaching. These findings highlight the need for optimal pigment loading and UV stabilization to extend the shelf life of thermochromic food packaging materials in light-exposed storage and retail environments. The study offers a framework for improving the long-term reliability of smart packaging in the food industry. This work uniquely integrates optical, mechanical, and mass loss analyses to evaluate thermochromic packaging degradation under extended UVA exposure. Full article

The critical wind speed for stalk breaking is a direct and rapid method for evaluating stalk-breaking resistance. Maize lodging resistance is determined by the plant’s wind-induced stress and the stalk’s mechanical strength, yet the factors influencing plant stress remain unclear. This study analyzed the quantitative relationship between plant leaf area, weight, and stalk base torque by implementing different leaf-cutting and ear-removal treatments. The key factors affecting plant stress under varying wind speed conditions were identified. Results indicated that the critical wind speed for stalk breaking significantly increased following leaf cutting and ear removal. Under different wind speed conditions, stalk base torque exhibited a significantly negative correlation with the critical wind speed for stalk breaking, with the strongest correlation observed at U = 14.6 m s⁻¹. At this wind speed, every 1 m² increase in leaf area resulted in a torque increase of 6.7 N m and a decrease in critical wind speed for stalk breaking by 17.5 m s⁻¹. Similarly, every 1 kg increase in plant fresh weight led to an 8.1 N m torque increase and an 18.3 m s⁻¹ decrease in critical wind speed. Additionally, every 1 m increase in the height of the center of gravity resulted in a torque increase of 13.3 N m and a 22.9 m s⁻¹ reduction in critical wind speed. Regression analysis revealed that changes in critical wind speed for stalk breaking were primarily influenced by leaf area and plant fresh weight, which accounted for 80.6% of its variation. The effects of plant fresh weight and leaf area on torque varied under different wind speed conditions. In conclusion, maize leaf area, fresh weight, and center of gravity height influence the critical wind speed for stalk breaking by altering plant torque in a wind environment. Full article

This study aimed to develop a green and sustainable composite polysaccharide gel with antioxidant activity and freshness-monitoring properties. Blueberry pomace was repurposed to extract anthocyanins (BA), which were incorporated into chitosan (CS)/polyvinyl alcohol (PVA) and starch (S)/PVA matrices to prepare pH-indicating composite polysaccharide gels. The anthocyanin solution exhibited significant colorimetric responses to pH 2–14 buffer solutions. Comparative analyses revealed distinct performance characteristics: the CS/PVA-BA gel showed optimal elongation at break, low hydration (8.33 ± 0.57% water content), and potent antioxidant activity (DPPH: 73.59 ± 0.1%; ABTS: 77.47 ± 0.1%), whereas the S/PVA-BA gel demonstrated superior tensile strength and pH-responsive sensitivity. Structural characterization via FT-IR and SEM confirmed molecular compatibility between BA and polymeric matrices, with anthocyanins enhancing intermolecular hydrogen bonding. Applied to chilled beef (4 °C) freshness monitoring, the CS/PVA-BA gel exhibited color transformations from magenta-red (initial spoilage at 48 h: TVB-N > 15 mg/100 g, TVC > 4.0 lg CFU/g) to bluish-gray (advanced spoilage by day 6), correlating with proteolytic degradation metrics. These findings established a multifunctional platform for real-time food quality assessment through anthocyanin-mediated color changes in the composite gels, coupled with preservation activity, highlighting their significant potential as intelligent active packaging in the food industry. Full article

This study investigates the use of spent coffee grounds (SCGs) as a biofiller in polypropylene (PP) composites, produced via injection molding, as a sustainable alternative to conventional materials. The effects of varying SCG content (1%, 5%, 7%, and 10% w/w) on the flow behavior, thermal stability, mechanical properties, structural integrity, and morphology of the composites were systematically evaluated. Analyses using optical microscopy (OM) and Fourier-transform infrared spectroscopy (FT-IR) revealed significant changes in morphology and structure with SCG addition. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) showed improved thermal stability with increasing SCG content. Mechanical characterization indicated an enhanced hardness and tensile modulus, a near-constant tensile strength, and a decreased toughness and elongation at break with increasing SCG content. Melt flow index (MFI) measurements confirmed suitable processing characteristics. Overall, the PP/SCG composites demonstrate promising performance regarding sustainability and mechanical properties, suggesting their viability as an alternative to traditional materials. Full article

Natural rubber is a widely used biological polymer material because of its excellent comprehensive performance. Nevertheless, the performance of domestic natural rubber cannot meet the requirements for high-end products such as aviation tires, which has become a constraint on the innovation and upgrading of high-end manufacturing enterprises and the enhancement of global competitiveness in China. To solve the bottleneck problem of natural rubber processing technology, this study systematically analyzed the effects of different varieties of fresh latex ratios on the processing and dynamic properties of bio-coagulated natural rubber. By mixing PR107 and Reyan72059 fresh latex with Reyan73397 fresh latex according to proportion, the fresh latex was coagulated by enzyme-assisted microbials, and the effects of the fresh latex ratio on physical and chemical indexes, molecular weight distribution, vulcanization characteristics, processing properties, cross-link density and physical and mechanical properties of the natural rubber were analyzed. The results showed that the aging resistance of natural rubber coagulated with enzyme-assisted microbial decreased, and the aging resistance of natural rubber increased with the increase in the mixing ratio of PR107 and Reyan72059 fresh latex. The proportion of high molecular weight of the natural rubber coagulated with the enzyme-assisted microbial increased, and the fresh latex mixing had little effect on the molecular weight distribution curve. Under the carbon black formulation, the CRI of the enzyme-assisted microbial coagulated natural rubber compound was relatively larger. Under the same strain conditions, the H-3 compound (PR107:Reyan72059:Reyan73397 = 1:1:3) had the best viscoelasticity and the least internal resistance of rubber molecules. In addition, the cross-link density, tensile strength, elongation at break, and tear strength of H-3 vulcanized rubber were the largest, improved by 23.08%, 5.32%, 12.45% and 3.70% compared with the same H-2 vulcanized rubber. In addition, the heat generation performance was reduced by 11.86%, and the wear resistance improved. Full article

Chitosan (CS)-based films have demonstrated significant potential as biodegradable packaging materials, but their suboptimal barrier and mechanical properties limit practical applications. In this study, CS/carboxymethyl cellulose (CMC) composite films were prepared using a NaOH/urea-based alkaline system. Optimal ratios (1.5% CS, 2% CMC, 2.5% NaOH, and 4% urea) were determined through an L₁₆(4⁴) orthogonal array design. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses confirmed the formation of stable physical crosslinks between CS and CMC via hydrogen bonding. These interactions significantly enhanced mechanical properties (tensile strength: 46.08 MPa; elongation at break: 68%), improved thermal stability (maximum decomposition temperature: 304 °C), and superior barrier properties (water vapor transmission rate: 0.26 × 10⁻⁵ g/(m²·h·Pa); oxygen transmission rate: 1.12 × 10⁻⁴ g/(m²·s)). NaOH concentration exhibited the most pronounced influence on film performance. The composite film combines inherent biodegradability with excellent functional properties, offering a sustainable alternative to conventional petroleum-based packaging materials. Full article