Search Results (2,594)

Water vapor sorption in porous activated carbons (PACs) is governed by a complex interplay of pore architecture and surface functionality and often exhibits pronounced adsorption–desorption hysteresis. In this work, chestnut-shell-derived carbons were synthesized via a two-step thermal route—pyrolysis at 550 °C for 120 min followed by KOH activation at either 600 °C or 800 °C for 240 min—and evaluated using a dynamic vapor sorption analyzer to quantify water uptake, hysteresis, and temperature-dependent energetics. Both materials exhibit sigmoidal Type V isotherms, characteristic of cooperative water clustering on hydrophobic carbon surfaces with localized polar sites. At 25 °C, The PAC sample prepared at 800 °C shows a sharper uptake transition and higher total capacity (~0.45 g/g at 90% RH), compared to the broader, more gradual isotherm of the 600 °C sample (~0.17 g/g). Temperature-dependent isotherms collected between 25 °C and 45 °C were fit using the Dubinin–Serpinsky (DS-4) model, yielding good agreement (R² ≈ 0.997) and enabling mechanistic interpretation of primary site adsorption and cooperative cluster growth. Clausius–Clapeyron analysis of ln P versus 1/T at fixed loadings yielded isosteric heats of adsorption (ΔH) decreasing from approximately 45.4 kJ mol⁻¹ at low uptake (0.02 g g⁻¹) to ~43.8 kJ mol⁻¹ at intermediate loading, followed by a slight increase to ~44.2 kJ mol⁻¹ at higher coverage (0.35 g g⁻¹). This trend reflects the transition from strong adsorption at high-energy surface sites to cooperative water clustering and confinement effects within the pore network. These findings highlight the role of activation temperature in modulating sorption mechanisms and energetics, offering practical guidance for tuning biomass-derived carbons for atmospheric water harvesting applications. Full article

To address the mounting environmental burden caused by solid waste from the food supply chain—specifically agricultural residues and plastic packaging—this study systematically investigated the synergistic mechanisms and product regulation pathways in the co-pyrolysis of four representative food processing by-products—rice husk, pine wood, corn stover, and chestnut shell—with polypropylene, a common food packaging material. A comprehensive methodology integrating thermogravimetric analysis, kinetic modeling, and product characterization was employed. The results demonstrate that incorporating polypropylene into co-pyrolysis systems, such as those involving waste oil, significantly reduces the average activation energy, indicating a catalytic effect that enhances reaction kinetics. Notably, the co-catalytic interaction between corn stover and PP led to a substantial 54.90% reduction in oxygen content, underscoring PP’s role as an effective hydrogen donor that promotes deoxygenation and free radical reactions, thereby increasing hydrocarbon production. At an optimal pyrolysis temperature of 600 °C, product distribution was effectively regulated: the hydrocarbon yield in the CP (corn stover/PP) system increased from 39.8% to a maximum of 65.6%, reflecting a targeted conversion of oxygenated compounds into high-value hydrocarbons. Furthermore, greenhouse gas (GHG) emission calculation and techno-economic analyses indicate that a natural gas-assisted co-pyrolysis process (Scenario C) can generate a net daily profit of 1835 RMB while reducing annual CO₂ emissions by 6515 tons, demonstrating both economic feasibility and environmental benefits. This study provides a theoretical foundation for the circular economy in the food industry, offering a viable technical pathway for the simultaneous treatment of organic food waste and packaging plastics, thereby supporting the sustainable development of the agri-food sector. Full article

Addressing the thermal management challenges of prismatic aluminum shell lithium battery modules in electric vehicles under high-rate charge–discharge conditions, this study proposes a multi-objective optimization design method for integrated biomimetic liquid cooling plates. By integrating various highly efficient heat transfer structures from nature, including fractal-tree-like networks, leaf vein branching systems, and spider web radial distribution, a novel biomimetic liquid cooling plate topology was constructed. A multi-physics coupled numerical model considering electrochemical heat generation, thermal conduction, convective heat transfer, and thermal stress deformation was established. The NSGA-II algorithm was employed to globally optimize 12 design variables including channel geometric parameters, operating conditions, and structural dimensions, achieving collaborative optimization objectives of maximum temperature minimization, temperature uniformity maximization, pressure drop minimization, and structural lightweighting. The weight coefficients for the four optimization objectives were determined through the Analytic Hierarchy Process (AHP) with verified consistency (CR = 0.02 < 0.10), ensuring rational priority allocation aligned with automotive safety standards. The optimization results demonstrated that compared to the initial design, the optimal solution reduced the maximum temperature under 3C discharge conditions by 9.9% to 34.7 °C, decreased the temperature difference by 31.3% to 3.3 °C, lowered the pressure drop by 24.6% to 2150 Pa, reduced structural mass by 4.0%, and decreased maximum stress by 16.7%. Quantitative comparison with single biomimetic structures under identical boundary conditions showed that the integrated design achieved a 3.3% lower maximum temperature and 25.7% better flow uniformity than the best-performing single structure, demonstrating the synergistic advantages of multi-biomimetic integration. These synergistic performance improvements can be attributed to the hierarchical multi-scale architecture where fractal networks provide macro-scale flow distribution, leaf vein branches ensure meso-scale coverage, and spider web radials achieve micro-scale thermal matching. Long-term cycling tests conducted at 1C/1C rate with 25 ± 1 °C ambient temperature showed that the optimized design maintained a capacity retention rate of 92.3% after 1000 charge–discharge cycles, demonstrating excellent durability. The complex biomimetic channel structure can be fabricated using selective laser melting technology with minimum feature sizes below 0.3 mm, indicating promising manufacturing feasibility. The research findings provide theoretical guidance and technical support for the engineering design of high-performance battery thermal management systems. Full article

The rolling seal is a pivotal sealing technology for marine equipment such as wet-mateable connectors, ensuring operational integrity in deep-sea environments during both static and mating phases. However, its working mechanisms remain inadequately understood, and the effects of sealing parameters and seawater pressure have yet to be systematically studied. To address these issues, a refined model for rolling seals operating in deep-sea pressure-balanced conditions was developed. The model’s accuracy was enhanced by incorporating two key inputs: experimentally measured boundary lubrication friction coefficients (replacing conventional dry friction values) for finite element simulation and torque calculation, and oil pressure under pressure-balanced conditions, derived from shell theory, as a boundary load. Through systematic parametric simulations, the effects of interference fit, rotational speed, and seawater pressure on sealing performance were elucidated. An experimental torque test setup under atmospheric pressure was constructed to validate the numerical model. The results indicate that, while ensuring reliable static sealing, higher rotational speeds and smaller interference fits help reduce rotational torque. Benefiting from the pressure-balanced design, increasing water depth significantly enhances hydrodynamic performance—accounting for over 90% of the total static contact pressure at 1500 m—while leakage shows a decreasing trend. These findings provide theoretical insights for optimizing deep-sea sealing structures. Full article

Statistical Energy Analysis (SEA) requires a physically meaningful subsystem definition, whereas manual partitioning of complex shell structures is often time-consuming and strongly dependent on engineering experience. To address this issue, this study proposes an automatic initial subsystem partitioning framework for shell FE models based on explicit prior attributes available in the model definition. The method unifies four classes of physical discontinuities—geometric discontinuity, thickness discontinuity, material/property discontinuity, and topological discontinuity—within a single adjacency evaluation procedure. The shell FE mesh is represented through element adjacencies, and adjacencies crossing any identified physical discontinuity are removed so that the remaining connected components define the partitioned subsystems. In this way, the framework generates partitioning results with explicit boundaries and traceable origins without relying on posterior response-field analysis or manually prescribed subsystem boundaries. Because the procedure operates directly on existing large-scale shell FE models and does not require additional response-feature construction or complex pre-partitioning, it provides a lightweight, repeatable, and practically executable automation path for SEA-related front-end modeling. The resulting partitions are intended as physically explicit initial partitioning results that provide a reliable boundary basis for higher-level statistical modeling objectives. When a coarser subsystem representation is required for subsequent modeling, further aggregation may be introduced as an optional enhancement according to the modeling objective, rather than as a prerequisite for the validity of the present method. Full article

The increasing adoption of high-aspect-ratio wings to improve aerodynamic efficiency introduces significant structural flexibility, necessitating the integration of aeroelastic considerations into the earliest design stages. While critical, existing frameworks often lack the multi-fidelity modeling capabilities and automated workflows required to bridge conceptual design and high-fidelity verification. This paper presents the Flexible Aero-Structural Toolbox (FAST), a modular framework supporting both beam and shell structural modeling and integrated with MSC NASTRAN for industry-standard aeroelastic simulation. The toolbox’s capabilities are demonstrated through modal, flutter, and static aeroelastic analyses across three distinct configurations: the P-FLEX UAV, the Ventus sailplane, and an A320-like transport aircraft, including its hydrogen-powered derivative. Results show that FAST accurately captures the aeroelastic characteristics of high-aspect-ratio wings and effectively predicts loads for large-scale flexible airframes. Notably, analysis of the hydrogen configuration reveals a significant 25% increase in wing bending moments for the “dry” wing condition compared to standard kerosene configurations. Furthermore, the tool’s ability to model unconventional mass distributions, such as cryogenic fuel tanks, highlights its adaptability for disruptive aircraft technologies. The study concludes that FAST provides a versatile, physics-based decision-making environment that significantly improves efficiency in the aeroelastic analysis process without compromising simulation fidelity. Full article

Hollow graphitic nanoshells (HGSs) are widely investigated as battery materials because their conductive shells and internal voids can simultaneously influence ion transport, electron percolation, and mechanical stress accommodation. Yet, the field remains largely morphology-driven, with performance often attributed generically to “hollowness” rather than to structural parameters. This review examines HGSs from a parameter-oriented perspective. It highlights key structural features, including graphitization degree, shell thickness, cavity size, pore architecture, and defect or dopant chemistry. These features collectively shape electrochemical behavior. We discuss how these features influence transport kinetics, interphase stability, volumetric efficiency, and mechanical resilience across insertion, metal anode, multivalent, solid-state, and halogen chemistries. Major synthesis approaches, including hard-templated, soft-templated, self-templated, and biomass-derived routes, are evaluated based on the structural control they provide and the influence of synthesis conditions on shell architecture, graphitic ordering, and pore structure. Special attention is given to how these structural features develop during processing and how they affect ion accessibility, conductivity, and stability. Finally, we outline a shift toward quantitative, parameter-driven engineering supported by operando diagnostics, electrode-level modeling, and standardized reporting. HGSs will only achieve practical relevance when structural optimization extends beyond particle morphology to transport uniformity, interfacial stability, network connectivity, and life-cycle responsibility. Full article

Low-density cancellous bone results in reduced trabecular support and may increase crestal cortical strain around implants. Osseodensification (OD) compacts trabecular bone and may create a peri-osteotomy densified zone, but its strain-level effects in osteoporotic-like bone are unclear. This study evaluated whether an OD-inspired peri-implant densified trabecular zone reduces crestal cortical strain compared with conventional drilling (CD) in an osteoporotic-like model. A three-dimensional finite element model of a mandibular posterior segment with a 2.0-mm cortical shell and D4 cancellous core was constructed with a 4.3 × 11.4-mm titanium implant and a cemented monolithic zirconia crown. CD used a 4.0-mm osteotomy in D4 bone. The OD model used the same osteotomy plus a concentric peri-implant densified shell with radial density gradation from D1 to D3. The implant–bone interface was defined as bonded. Static 100 N axial and 45° oblique loads were applied. Outcomes were ε_eq, ε_max, and ε_min, summarized as mean top-10 nodal values. OD reduced crestal cortical strains under both loads. Under axial loading, ε_eq, ε_max, and |ε_min| decreased by 17.7%, 19.0%, and 24.1%, respectively. Under oblique loading, the corresponding reductions were 9.8%, 8.0%, and 8.9%. Oblique loading produced higher cortical strains than axial loading in both models. OD-inspired peri-implant densification reduced crestal cortical strain in this osteoporotic-like model, whereas oblique loading remained the main driver of elevated strain. These findings support occlusal/prosthetic strategies that minimize oblique forces and warrant experimental and clinical validation. Full article

The Compact Strip Production (CSP) process is the latest version of thin-slab continuous casting, combining both casting and rolling, thus improving the CSP process’s energy efficiency and the strip quality. Modeling the combined phenomena of fluid flow, heat transfer and solidification in CSP casting remains an unresolved multiphysics problem, particularly when boron and other alloying elements enter the system and modify the thermal properties and solidification behavior. In this study, we propose a more integrated approach by executing a computational fluid dynamics (CFD) model at different scales, blending macroscale fluid flow and heat transfer with meso-solidification that is molten in a CSP casting model. For the macroscale model, we solve the Reynolds-Averaged Navier–Stokes (RANS) equations with one of the energy equations, while the mesoscale model uses the solid fraction evolution algorithm to model the multiphase latent heat of solidification and the motion of solid and liquid phases of a non-equilibrium system. Mold heat flux, free surface cooling and secondary spray zones were used to set the boundary conditions. The model simulates temperature distributions at different times, the solid fraction below the liquidus and the trends in shell growth for different process parameters and the time profile of the solidification. The improved prediction capability of the model, demonstrated by the results, opens the opportunity to reduce the process parameters of casting speed and cooling to defect-free results. Comparisons with the most recent studies on continuous casting processes (including CSP and thin slabs) demonstrate alignment with the thermal gradient and solidification behavior characteristics. The thermal gradients and solidification behavior characteristics were obtained. The research yields the basis for developing microstructure and segregation models with boron-alloyed steels. Full article

Water is fundamental to structural integrity, stability, and functional properties of food systems, biomaterials, and biobased industries. The dynamics of hydration, including hydrogen bonding, hydration shell formation, plasticization, and phase transitions, dictate molecular behavior and exert broad influence on energy consumption, shelf life, biodegradability, and resource efficiency. However, the nonlinear and multiscale characteristics of hydration have constrained the predictive capabilities of conventional empirical methods. This study introduces a comprehensive framework that integrates foundational hydration science with advanced computational intelligence to model, predict, and optimize hydration-driven phenomena across diverse biopolymer classes. Leveraging classical insights into carbohydrate stereochemistry, protein hydrophobic hydration, and phospholipid-bound water, we demonstrate how computational approaches can reduce resource use in bioprocessing by 30–50% and optimize drying curves to lower energy consumption by 25%. By establishing hydration as a strategic design parameter, this work charts a pathway toward a resilient and sustainable economy where predictive error rates for hydration dynamics are significantly minimized through data-driven calibration. Full article

Circular pipe-jacking construction in gravel strata faces significant technical challenges, including high frictional resistance, elevated permeability, and susceptibility to collapse. Optimizing the formulation of thixotropic slurry is crucial for improving the construction quality and efficiency of such projects. This study, based on the Ruyang Water Supply Project of the North Main Canal in the Qianping Irrigation Area, Henan Province, China, systematically investigated slurry formulation using bentonite, soda ash, sodium carboxymethyl cellulose (CMC), polyacrylamide (PAM), and shell powder as raw materials. An orthogonal experimental design was employed to optimize the mix proportions, and the friction-reduction performance was validated through drag-friction model tests. The results indicate that the optimal slurry formulation is: bentonite 8%, soda ash 0.3%, CMC 0.2%, PAM 0.15%, shell powder 4%, and water 87.35%. This formulation exhibits excellent fluidity and thixotropy, facilitating the formation of a stable slurry film. Consequently, the friction coefficient between concrete specimens and gravel soil was reduced by 35.6%. The inclusion of shell powder significantly enhanced the slurry’s cohesiveness and improved the anti-seepage capacity of the surrounding stratum due to its filling effect. The optimized thixotropic slurry effectively mitigates frictional resistance during pipe jacking in gravel strata and enhances the formation’s resistance to collapse. The findings of this study provide a viable technical reference for pipe-jacking projects under similar geological conditions. Full article

Vibrations of thin sheet-metal parts during robotic manipulation on a production line create a number of serious challenges for production process planning. Modeling the behavior of an elastic plate or shell as a function of the robot manipulator trajectory is typically performed using the finite element method (FEM) and requires significant computational effort. The time factor remains a key limitation for integrating operations involving flexible parts into the virtual commissioning process. In this work, a methodology is proposed that enables accurate real-time reproduction of the behavior of an elastic part during linear robotic manipulation. The approach is based on modeling the response of an elastic part to a prescribed base excitation using the FEM and on the development of a reduced model compliant with the FMI/FMU standard. This reduced model computes, in real time, the convolution of the precomputed base response with the acceleration profile corresponding to the robot TCP trajectory. This makes it possible to determine the total cycle duration, which consists of the part transfer time and the time required for vibration decay at the end of the trajectory down to an acceptable threshold, as well as to perform collision checking while accounting for the deformation of the flexible part. As a result, operations involving elastic parts can be integrated into the virtual commissioning process. Full article

Enrofloxacin (ENR), as a widely used antimicrobial agent in aquaculture, poses potential risks to ecosystems and human health due to its environmental persistence. Therefore, it is of great significance to explore efficient methods for removing ENR from aquaculture wastewater. In this study, a series of shrimp shell-derived aerogel (MBC300–MBC700) were fabricated from Litopenaeus vannamei shells through chemical modification followed by pyrolysis at 300–700 °C, and their adsorption performance and mechanisms toward ENR were systematically investigated. The modified porous materials exhibited a well-developed micro–mesoporous structure, high specific surface area, and abundant surface functional groups. Meanwhile, MBC400 demonstrated the highest adsorption capacity for ENR, reaching 14.56 mg/g, with a corresponding specific surface area of 77.71 m²/g. The adsorption kinetics followed the pseudo-second-order model, and the isothermal data were better fitted by the Freundlich model, indicating a chemisorption-dominated, heterogeneous multilayer adsorption process. Thermodynamic analysis revealed that the adsorption was spontaneous (ΔG < 0) and endothermic (ΔH > 0). In regeneration experiments, 30% ethanol solution achieved the best desorption efficiency for MBC400, with adsorption efficiency remaining above 75% after three cycles. Based on the characterization and adsorption results, adsorption mechanism of ENR on MBC400 was elucidated as a synergistic effect of hydrogen bonding, π–π stacking, electrostatic interaction, and surface complexation. This study provides a novel strategy and theoretical basis for the high-value utilization of shrimp shell waste and for the efficient removal of fluoroquinolone antibiotics from aquaculture effluents. Full article

Background: Curcumin (Cur) has therapeutic potential for inflammatory bowel disease (IBD) but is limited by its poor bioavailability. Methods: This study demonstrated that Cur-loaded core–shell structured microgel nanoparticles (LF/CP-Cur MN), fabricated through electrostatic complexation between lactoferrin and citrus pectin, followed by Ca²⁺ consolidation, overcome this limitation. Results: These nanoparticles effectively reduced the bitterness and astringency of curcumin while prolonging its release time. In an IBD mouse model, LF/CP-Cur MN treatment mitigated symptoms and inflammation of IBD, and restored intestinal barrier integrity. Crucially, compared with free Cur, the LF/CP-Cur MN enhanced colon-targeted accumulation of Cur and favorably modulated the gut microbiota by increasing beneficial genera like Lactobacillus and Dubosiella, while suppressing harmful genera like Enterobacter, thereby promoting levels of acetate, propionate, and butyrate. Conclusions: These findings highlight the potential of the LF/CP-Cur MN to improve Cur bioaccessibility and exert dual functional roles in modulating gut microbiota and alleviating inflammation, thus offering a promising dietary strategy for the management of IBD. Full article

This study presents an ASME-based structural assessment of the head–shell junction in a 60 m³ pressurized railway tank wagon subjected to an internal pressure of 0.45 MPa, combining classical shell theory with finite element analysis (FEA) in accordance with ASME Section VIII Division 2 stress categorization and linearization procedures. An analytical model based on the moment theory of shells of revolution was developed to describe displacement and rotation compatibility at the ellipsoidal head–cylindrical shell junction, allowing for the determination of contour interaction loads governing membrane–bending coupling in the discontinuity region. The calculated contour loads (Q₀ = 795 N/mm, M₀ = 13,350 N·mm/mm) indicate localized membrane–bending interactions caused by geometric discontinuity. Finite element simulations using axisymmetric (2D) and full 3D models were evaluated through the ASME VIII-2 stress linearization procedure, enabling comparison between analytical predictions and numerical results. The maximum equivalent stress according to the Coulomb–Tresca criterion reached 115 MPa (2D) and 117 MPa (3D), with less than 2% deviation, confirming the adequacy of the axisymmetric model. Stress linearization shows that the maximum combined primary membrane and bending stress (109.5 MPa) remains well below the ASME allowable limit of 308 MPa, while the discontinuity influence zone extends approximately 120–150 mm from the junction. The results confirm compliance with ASME VIII Division 2 requirements and demonstrate that the combined analytical–numerical approach provides a reliable method for evaluating stress concentration effects in railway tank wagons. Full article