Search Results (832)

The frequent blasting in underground mines results in stress waves of different intensities, which is one of the main factors leading to backfill collapse. Improving the strength of backfill is an effective way to reduce the backfill damage. In this study, rice straw fiber and graded tailings were used as raw materials to prepare rice straw fiber-reinforced cemented tailings backfill (RSCTB). An orthogonal experimental design was employed to perform unconfined compressive strength (UCS) tests, diffusivity measurements, and Split Hopkinson Pressure Bar (SHPB) tests. The results showed that straw fibers slightly reduce slurry fluidity. The UCS of RSCTB at a specific mix ratio was more than 50% higher than that of cemented tailings backfill (CTB) without rice straw. The dynamic unconfined compressive strength (DUCS) of RSCTB increased linearly at different strain rates. The effect of rice straw fibers on the UCS and DUCS was much smaller than that of cement content and solid mass concentration. Excessively long and abundant straw fibers are not conducive to improving the long-term impact resistance of RSCTB. Full article

A bioresorbable cannulated bone screw was developed using PLA/PCL-based composites reinforced with hydroxyapatite (HA) and titanium dioxide (TiO₂), two additives previously reported to enhance mechanical compliance, biocompatibility, and molding feasibility in biodegradable polymer systems. The design incorporated a crest-trimmed thread and a strategically positioned gate in the thin-wall zone opposite the hexagonal socket to preserve torque-transmitting geometry during micromolding. To investigate shrinkage behavior, a Taguchi orthogonal array was employed to systematically vary micromolding parameters, generating a structured dataset for training a back-propagation neural network (BPNN). Analysis of variance (ANOVA) identified melt temperature as the most influential factor affecting shrinkage quality, defined by a combination of shrinkage rate and dimensional variation. A hybrid AI framework integrating the BPNN with genetic algorithms and particle swarm optimization (GA–PSO) was applied to predict the optimal shrinkage conditions. This is the first use of BPNN–GA–PSO for cannulated bone screw molding, with the shrinkage rate as a targeted output. The AI-predicted solution, interpolated within the Taguchi design space, achieved improved shrinkage quality over all nine experimental groups. Beyond the specific PLA/PCL-based systems studied, the modeling framework—which combines geometry-specific gate design and normalized shrinkage prediction—offers broader applicability to other bioresorbable polymers and hollow implant geometries requiring high-dimensional fidelity. This study integrates composite formulation, geometric design, and data-driven modeling to advance the precision micromolding of biodegradable orthopedic devices. Full article

This study presents the development and optimization of a flexible integrated three-in-one micro-sensor using Micro-Electro-Mechanical Systems (MEMS) technology. To enhance its reliability and performance, the Taguchi Method was employed to analyze and optimize key fabrication parameters, including the electrode area, electrode thickness, and protective layer thickness. An L4 orthogonal array design enabled efficient experimentation with minimal runs. Experimental results demonstrate that optimized parameter combinations significantly improve sensor linearity, sensitivity, and reproducibility. Comparative analysis with commercial sensors shows the superior reliability of the self-fabricated sensor, particularly in airflow velocity detection. The findings validate the use of the Taguchi Method for robust MEMS sensor design and highlight its potential for industrial heating, ventilation, and air conditioning (HVAC) applications. Full article

Droplet-based microlens fabrication using Ultra Violet (UV) curable polymers demands the precise measurement of three-dimensional geometries, especially for non-axisymmetric shapes influenced by electric field deformation. In this work, we present a polar coordinate-based contour fitting method combined with Hermite interpolation to reconstruct 3D droplet geometries from two orthogonal shadowgraphy images. The image segmentation process integrates superpixel clustering with active contours to extract the droplet boundary, which is then approximated using a spline-based polar fitting approach. The two resulting contours are merged using a polar Hermite interpolation algorithm, enabling the reconstruction of freeform droplet shapes. We validate the method against both synthetic Computer-Aided Design (CAD) data and precision-machined reference objects, achieving volume deviations below 1% for axisymmetric shapes and approximately 3.5% for non-axisymmetric cases. The influence of focus, calibration, and alignment errors is quantitatively assessed through Monte Carlo simulations and empirical tests. Finally, the method is applied to real electrically deformed droplets, with volume deviations remaining within the experimental uncertainty range. This demonstrates the method’s robustness and suitability for metrology tasks involving complex droplet geometries. Full article

Hybrid fiber-reinforced concrete (HFRC), renowned for its significantly enhanced mechanical properties and structural integrity, is widely used in infrastructure construction and has become a key avenue of modern high-performance concrete development. The hybrid application of basalt fiber (BF) and polypropylene fiber (PPF) at optimized ratios generates synergistic effects, improving both mechanical performance and material service reliability. To explore and evaluate the synergistic mechanism of BF-PPF hybrid fibers on concrete’s mechanical properties and performance, this study employs an orthogonal experimental design and mechanical testing methods, measuring the materials’ static compressive strength (loading rate: 0.6 mm/min), splitting tensile strength (loading rate: 0.12–0.14 MPa/s), dynamic elastic modulus (measured by the ultrasonic method), and dynamic compressive strength (loading rates: 0.6 mm/min, 6 mm/min, and 60 mm/min). For these tests, we prepared 100 mm × 100 mm × 100 mm cubic specimens (for static compressive, dynamic compressive, and splitting tensile tests) and 400 mm × 100 mm × 100 mm prismatic specimens (for dynamic elastic modulus tests), with three parallel specimens in each test group. In addition, the microstructure was characterized by scanning electron microscopy (SEM) to observe the fiber-matrix interaction. The results show that when the BF/PPF volume ratio is 1:2 (BF0.05PPF0.1), the concrete’s compressive strength, splitting tensile strength, and elastic modulus increase by 13.7%, 76.3%, and 116.0%, respectively, with corresponding synergistic effect indices (Q) of 0.057, 0.213, and 0.241, indicating obvious positive synergy. Under dynamic loading, hybrid combinations with higher PPF content (e.g., BF0.05PPF0.1) exhibit strain-rate-dependent enhancements in compressive strength and better impact resistance. SEM analysis reveals that fibers inhibit microcrack propagation through fiber bridging, network distribution, and pull-out resistance, while also improving the interfacial transition zone’s structure. These findings provide theoretical support for the engineering application of composite fiber-reinforced concrete materials. Full article

Tool structure design methodologies predominantly rely on trial-and-error approaches or single-objective optimization but fail to achieve coordinated enhancement of multiple performance metrics while lacking thorough investigation into complex cutting coupling mechanisms. This study proposes a multi-objective optimization framework integrating joint simulation approaches. First, a finite element model for orthogonal turning was developed, incorporating the hyperbolic tangent (TANH) constitutive model and variable coefficient friction model. The cutting performance of four micro-groove configurations is comparatively analyzed. Subsequently, parametric modeling coupled with simulation–data interaction enables multi-objective optimization targeting minimized cutting force, reduced cutting temperature, and decreased wear rate. The Non-dominated Sorting Genetic Algorithm II (NSGA-II) explores Pareto-optimized solutions for arc micro-groove geometric parameters. Finally, optimized tools manufactured via powder metallurgy undergo experimental validation. The results demonstrate that the optimized tool achieves significant improvements: a 19.3% reduction in cutting force, a 14.2% decrease in cutting temperature, and tool life extended by 33.3% compared to baseline tools. Enhanced chip control is evidenced by an 11.4% reduction in chip curl radius, accompanied by diminished oxidation/adhesive wear and superior surface finish. This multi-objective optimization methodology effectively overcomes the constraints of conventional single-parameter optimization, substantially improving comprehensive tool performance while establishing a reference paradigm for cutting tool design under complex operational conditions. Full article

During the cooling phase of injection molding, the conformal cooling channel system optimizes the uniformity of mold temperature, diminishes warping deformation, and contributes substantially to heightened product precision. The injection molding process involves complex process parameters that may result in uneven cooling between components, leading to prolonged cycle times, increased shrinkage depth, and warping deformation of the plastic parts. These manifestations negatively impact the surface quality and structural strength of the final product. This article combined theoretical algorithms with finite element simulation (CAE) methods to optimize complex injection molding processes. Firstly, the characteristics of six different types of materials were examined. Melt temperature, mold opening time, injection time, holding time, holding pressure, and mold temperature were chosen as optimization variables. Meanwhile, the warpage deformation and shrinkage depth of the formed sample were selected as optimization objectives. Secondly, an L27 orthogonal experimental design (OED) was established, and the signal-to-noise ratio was processed. The entropy weight method (EWE) was used to calculate the weights of the total warpage deformation and shrinkage depth, thereby obtaining the grey correlation degree. The influence of process parameters on quality indicators was analyzed using grey relational analysis (GRA) to calculate the range. A second-order polynomial regression model was established using response surface methodology (RSM) to investigate the effects of six factors on the warpage deformation and shrinkage depth of injection molded parts. Finally, a comprehensive comparison was made on the impact of various optimization methods and models on the forming parameters. Analyze according to different optimization principles to obtain the corresponding optimal process parameters. The research results indicate that under the principle of prioritizing warpage deformation, the effectiveness ranking of the three optimization analyses is RSM > OED > GRA. The minimum deformation rate is 0.1592 mm, which is 27.37% lower than before optimization. Under the principle of prioritizing indentation depth, the effectiveness ranking of the three optimization analyses is OED > GRA > RSM. The minimum depth of shrinkage is 0.0312 mm, which is 47.21% lower than before optimization. This discovery provides strong support for the optimal combination of process parameters suitable for production and processing. Full article

Fly ash, as the main solid waste of coal-fired power plants, is an environmental problem that needs to be solved due to its massive accumulation. The mechanical properties and optimization mechanism of lightweight aggregate concrete prepared by using new single-cylinder rotary kiln fly ash ceramic granules as aggregate were systematically investigated. Through orthogonal experimental design, combined with macro-mechanical testing and microscopic characterization techniques, the effects of cement admixture and ceramic granule admixture on the properties of concrete, such as compressive strength, split tensile strength, and modulus of elasticity, were analyzed, and the optimization scheme of key parameters was proposed. The results show that the new single rotary kiln fly ash ceramic particles significantly improve the mechanical properties of concrete by optimizing the porosity (water absorption ≤ 5%), and its 28-day compressive strength reaches 46~50.9 MPa, which is 53.3~69.7% higher than that of the ordinary ceramic concrete, and the apparent density is ≤1900 kg/m³, showing lightweight and high-strength characteristics. X-ray diffraction (XRD) analysis shows that the new ceramic grains form a more uniform, dense structure through the synergistic effect of internal mullite crystals and dense glass phase; computed tomography (CT) scanning shows that the total volume rate of cracks of the new ceramic concrete was reduced by up to 63.8% compared with that of ordinary ceramic concrete. This study provides technical support for the utilization of fly ash resources, and the prepared vitrified concrete meets the demand of green building while reducing structural deadweight (20~30%), which has significant environmental and economic benefits. Full article

As wind energy development continues to expand toward nearshore and deep-sea regions, enhancing the aerodynamic efficiency of vertical axis wind turbines (VAWTs) in complex marine environments has become a critical challenge. To address this, a composite flow control strategy combining leading-edge suction and trailing-edge gurney flap is proposed. A two-dimensional unsteady numerical simulation framework is established based on CFD and the four-equation Transition SST (TSST) transition model. The key control parameters, including the suction slot position and width as well as the gurney flap height and width, are systematically optimized through orthogonal experimental design. The aerodynamic performance under single (suction or gurney flap) and composite control schemes is comprehensively evaluated. Results show that leading-edge suction effectively delays flow separation, while the gurney flap improves aerodynamic characteristics in the downwind region. Their synergistic effect significantly suppresses blade load fluctuations and enhances the wake structure, thereby improving wind energy capture. Compared to all other configurations, including suction-only and gurney flap-only blades, the composite control blade achieves the most significant increase in power coefficient across the entire tip speed ratio range, with an average improvement of 67.24%, demonstrating superior aerodynamic stability and strong potential for offshore applications. Full article

Arsenic pollution in paddy soil is a major environmental issue, and its remediation has become a subject of broad interest. Geo-electrochemical technology has been shown to have significant potential for remediating heavy metal-contaminated soils in recent years. Taking contaminated paddy soil from northern Guangxi as the research subject, this study aims to assess the effectiveness of geo-electrochemical technology for arsenic remediation. An orthogonal experimental design was used to identify the optimal combination of parameters, including power supply duration, voltage gradient, power supply mode, and electrolyte type. The arsenic removal efficiency was thoroughly assessed, and the underlying remediation mechanisms associated with geo-electrochemical technology combined with EDTA-2Na were extensively investigated. The findings revealed a substantial decrease in the residual arsenic fraction after treatment, accompanied by a substantial increase in the mobility and bioavailability of arsenic. The maximum removal rate of arsenic from the soil was determined to be 19.59%. Among the analyzed factors, electrolyte type exerted the most significant influence on the arsenic removal efficiency, followed by power supply duration and voltage gradient, while the impact of the power supply mode was less significant. The optimal remediation effect was achieved under the following conditions: a power supply duration of 108 h, a voltage gradient of 0.6 V/cm, continuous power supply mode, and the use of EDTA-2Na as the electrolyte. The multiple strong coordinating atoms in EDTA-2Na can form stable chelates with Fe³⁺ and Al³⁺ bound to arsenic in the soil, thereby causing the desorption of arsenic. The integration of geo-electrochemical technology with EDTA-2Na forms a synergistic multiphase electrochemical reaction mechanism, significantly improving the overall remediation efficiency in arsenic-contaminated soils. Full article

Given the demand for sustainable food solutions in China and the underutilization of bovine by-products, this study aimed to optimize the marinating process of bovine liver, heart, and rumen while evaluating their storage stability. An orthogonal experimental design was employed to systematically optimize the marinating agent ratio and incorporate natural antioxidants to inhibit lipid oxidation and microbial spoilage. Results demonstrated that the optimized marinating formula, which included 0.3 g/kg rosemary extract, exhibited optimal antioxidant and antimicrobial effects. This strategy not only slowed product pH decline but also improved product yield and texture, and significantly reduced thiobarbituric acid reactive substances (TBARS) values and carbonyl content (p < 0.05), while maintaining favorable sensory scores and extending shelf life. The study indicates that targeted marinating technology holds potential for transforming bovine by-products into high-value-added food products, offering innovative solutions to address both economic and environmental challenges and establishing a technical foundation for efficient by-product utilization and industrial upgrading. Full article

The anaerobic co-digestion of agricultural residues emerges as a promising strategy for energy recovery and nutrient recycling within circular agricultural systems. This study aimed to optimize co-digestion parameters for vinegar residue (VR) and cattle manure (CM) using an orthogonal experimental design. Three key variables were investigated which are the co-substrate ratio (VR to CM), feedstock-to-inoculum (F/I) ratio, and total solids (TS) content. Nine experimental combinations were tested to evaluate methane yield, feedstock degradation, and digestate characteristics. Results showed that the optimal condition for methane yield comprised a 2:3 co-substrate ratio, 1:2 F/I ratio, and 20% TS, achieving the highest methane yield of 267.84 mL/g volatile solids (VS) and a vs. degradation rate of 58.65%. Digestate analysis indicated this condition generated the most nutrient-rich liquid digestate and solid digestate, featuring elevated N, P, and K concentrations, acceptable seed germination indices (GI), and moderate humification levels. While total nutrient content did not meet commercial organic fertilizer standards, the digestate is suitable for direct land application in rural settings. This study underscores the need to balance energy recovery and fertilizer quality in anaerobic co-digestion systems, providing practical guidance for decentralized biogas plants seeking to integrate waste treatment with agricultural productivity. Full article

To address the issues of numerous influencing factors on material quality, difficulty in determining the optimal mix proportion, and the need to clarify the formation mechanism when foam concrete is used as an internal mold for prefabricated components, this study conducted orthogonal tests to investigate the influence laws of fly ash content, foam content, foaming agent dilution ratio, and water–binder ratio on the dry density and compressive strength of foam concrete, and determined the optimal mix proportion via analysis of variance (ANOVA). Additionally, scanning electron microscopy (SEM) tests were performed to analyze the effects of these four factors on the microscopic pore morphology of foam concrete from a microscopic perspective, thereby revealing its formation mechanism, and engineering applications were carried out. The results show that the primary-to-secondary order of factors affecting the dry density and compressive strength of foam concrete is as follows: foam content (B) > water–binder ratio (D) > foaming agent dilution ratio (C) > fly ash content (A). The optimal mix proportion is 5% fly ash content, 18% foam content, a 30-fold foaming agent dilution ratio, and a water–binder ratio of 0.55. Under this mix proportion, the pore size of foam concrete ranges from 200 μm to 500 μm with uniform distribution, and the pore spacing is between 20 μm and 30 μm, with almost no connected pores. When the foam concrete slurry sets and hardens, hydration products such as calcium silicate hydrate (C-S-H) gel, calcium hydroxide, ettringite (AFt), and monosulfate aluminate (AFm) are generated around the bubbles. The mechanical properties of foam concrete are afforded by the combined action of these hydration products and the pore structure. Full article

2.5D integrated circuits (ICs), which utilize an interposer to stack multiple dies side by side, represent a promising architecture for improving system performance, integration density, and design flexibility. However, the complex interconnect structures present significant challenges for post-fabrication testing, especially when scheduling test paths under constrained test access mechanisms. This paper addresses the test-path scheduling problem in interposer-based 2.5D ICs, aiming to minimize both total test time and cumulative inter-die interconnect length. We propose an efficient orthogonal learning-based differential evolution algorithm, named OLELS-DE. The algorithm combines the global optimization capability of differential evolution with an orthogonal learning-based search strategy and an elites local search strategy to enhance the convergence and solution quality. Comprehensive experiments are conducted on a set of benchmark instances with varying die counts, and the proposed method is compared against five state-of-the-art metaheuristic algorithms and CPLEX. Experimental results demonstrate that OLELS-DE consistently outperforms the competitors in terms of test cost reduction and convergence reliability, confirming its robustness and effectiveness for complex test scheduling in 2.5D ICs. Full article

The use of thermal insulation material in building envelopes is closely related to economic benefits, energy-savings, and carbon reduction of buildings. The construction forms of different components in building envelopes have an important influence on the optimization design of thermal insulation in building envelopes. In this study, an integrated optimization approach is proposed to search for the best solution of thermal insulation in external walls and the optimal combination scheme of different construction forms of envelope components in granaries. The integrated optimization approach consists of an orthogonal experimental design (OEDM) method-based determination module of an optimal combination scheme of different construction forms of components, an assessment model-based quantitative analysis module, and an integrated assessment indicator-based selection module of the best solution of external wall insulation. Firstly, the OEDM method is used to determine the optimal combination scheme of different construction forms of the foundation wall of an external wall, thermal insulation material, external window, roof, and floors in buildings. Secondly, integrated economic, energy, and carbon analysis models are developed to analyze comprehensive performance of external wall insulation. Finally, an integrated assessment indicator consisting of an energy balanced index, a carbon balanced index, and weight coefficients is presented to determine the best solution of external wall insulation. The applications of this optimization approach in different ecological grain storage zones in China demonstrated that the outdoor air temperature characteristics could affect the comprehensive performance of external wall insulation in granaries, significantly. The best solution of external wall insulation in granaries in Turpan city, Daqing city, Kaifeng city, Changsha city, Anshun city, and Danzhou city was expanded polystyrene insulation (EPS) with a layer thickness of 0.078 m, 0.048 m, 0.083 m, 0.089 m, 0.062 m, and 0.131 m, respectively. The greatest difference in the lowest entire construction cost and the lowest carbon emission of external wall insulation among different typical climate regions in China was 12.987 USD/m² and 6.3 kgCO2e/m², respectively. Full article