Search Results (297)

This study presents an analytical model for the long-term bending behavior of simply supported laminated glass (LG) plates with temperature-dependent viscoelastic interlayers. The glass layers are described based on three-dimensional elasticity theory, and the governing stress and displacement equations are formulated using the state-space method. The polymer interlayer is characterized by the generalized Maxwell model and the Williams–Landel–Ferry equation, while its time-dependent response is described through the Boltzmann convolution principle. By combining double Fourier series expansions with the Laplace-transform technique, analytical solutions for the stresses and displacements of multilayer LG plates are derived. The comparison shows that Kirchhoff–Love plate theory gives results close to the present solution for relatively thin LG plates, whereas the discrepancy becomes increasingly pronounced as the plate thickness increases. The finite element results agree well with those obtained from the proposed model; however, for the representative benchmark case, the present solution is approximately 1.13 × 10³ times faster than the FE simulation, and its memory usage is only about 10.88% of that required by the FE model. Parametric studies further reveal the effects of temperature, interlayer thickness, interlayer material, number of glass layers, and aspect ratio on the stress redistribution and deflection development of LG plates. Full article

This paper presents a comprehensive numerical modeling of nonlinear groundwater flow in a synthetic heterogeneous four-layer porous medium. Multilayered aquifer systems present significant modeling challenges due to nonlinear filtration and interlayer exchange processes. The mathematical model consists of four coupled nonlinear parabolic partial differential equations, where the nonlinearity arises from the dependence of hydraulic conductivity on hydraulic head. Vertical exchange between layers is described by Darcy’s law through separating aquicludes. The system is solved using a fully implicit finite-difference scheme by employing an alternating-direction implicit approach, resulting in a block-tridiagonal system of equations. The model is verified using analytical solutions and mass conservation tests. Application to a synthetic aquifer system demonstrates the model’s ability to reproduce complex transient behavior, including delayed response of upper layers to pumping and asymmetry of water-level drawdown cones due to nonlinear conductivity. The model’s greatest sensitivity is observed to the conductivity of the pumped layer and the vertical conductivity of the separating layers. The proposed approach represents a robust tool for groundwater management in structurally complex geological settings. Full article

In hybrid wire arc additive manufacturing with interlayer friction stir processing (UAMFSP), refined microstructures are produced in aluminum alloy builds; however, the thermal parameters governing layer-resolved defect evolution remain poorly understood. In this study, a correlative mechanistic framework is presented in which post-peak cooling rate is identified as a plausible controlling factor for porosity evolution in UAMFSP Al 4043 three-layer walls. A multi-scale characterization is performed by employing infrared thermography, quantitative optical grain morphology analysis (N  =  10,346 grains, Layers 1–3), scanning electron microscopy from 250× to 35,000×, and image-based porosity quantification from calibrated SEM fields. This primary quantitative comparison is established between L1 and L3 only; Layer 2 is excluded from the 250× quantitative analysis owing to its thermally distinct cooling regime and is treated separately. A counterintuitive layer-dependent porosity gradient is reported, wherein the upper layer (L3) exhibited 80% higher porosity (2.90 ± 1.18%) and 107% higher pore density (4283  ±  900 pores/mm²) than the bottom layer (L1), despite recording a 26% lower peak FSP surface temperature (195.1 vs. 263.2 °C) (n = three fields per layer; Cohen’s d ≈ 1.7). Based on these results, the post-peak cooling rate, rather than peak temperature, is identified as a plausible controlling factor for void consolidation quality, as evidenced by the observation that L3 cools at −12.3 °C/s versus −16.2 °C/s for L1, which is consistent with prolonged high-temperature dwell and reduced plastic-flow-assisted pore closure in the upper layer. The anomalously rapid cooling of L2 (−46.9 °C/s), attributed to a bilateral thermal gradient between the substrate and the air-cooled free surface, places it in a thermally distinct regime; accordingly, L2 is utilized exclusively for high-magnification SEM characterization in this study. High-magnification SEM imaging (12,000×–35,000×) revealed a frequent spatial co-location of sub-micron pores with fragmented Al–Si eutectic particles, which is consistent with preferential void persistence near particle–matrix interfaces. Grain morphology also exhibits non-monotonic evolution with build height, with mean circularity following the order L3 (0.645) > L1 (0.621) > L2 (0.569), and the equiaxed grain fraction ranging from 25.5% (L2) to 36.1% (L3) (ANOVA: F = 56.2, p = 5.15 × 10⁻²⁵), while the mean equivalent grain diameter remained below 3.4 μm across all layers. Overall, the outcomes of this study establish post-peak cooling rate, rather than peak temperature, as a plausible controlling factor for void consolidation quality in UAMFSP builds, with the caveat that complete causal isolation requires controlled single-variable experiments. These outcomes are presented as a first mechanistic framework for this class of hybrid process and are intended to motivate targeted controlled experiments, subsurface thermal characterization, and expanded porosity sampling in future investigations of multi-layer additive–deformation manufacturing of Al-based alloys. Full article

Tuning the d-band electronic structure of non-noble-metal catalysts is a central strategy for an alkaline hydrogen evolution reaction (HER), yet how composition controls the d orbital in multi-Wyckoff-site layered systems remains insufficiently understood. Here, layered (Fe_1-xNi_x)₃GaTe₂ single crystals (x = 0.2–1.0) were synthesized by the self-flux method as a platform to address this question. Single-crystal XRD and EDS confirm that Ni is uniformly incorporated into the parent P6₃/mmc framework while inducing a composition-dependent lattice evolution. Electrochemical measurements in 1.0 M KOH reveal a clear volcano-shaped composition dependence, peaking at x = 0.6, where the lowest overpotential, the smallest Tafel slope (94 mV dec⁻¹), the lowest charge-transfer resistance and the largest double-layer capacitance are simultaneously reached. First-principles calculations show that Ni doping reshapes the Fe-site d orbital strongly composition-dependent rate: the Fe d-band center upshifts rapidly by ~0.5 eV between x = 0.4 and x = 0.6, while the Ni d-band center stays nearly fixed in the same composition range. The maximum of HER activity therefore aligns with a steep upshift of the Fe d-band center rather than with the Ni content itself. Charge-density mapping of (Fe_0.4Ni_0.6)₃GaTe₂ further demonstrates that the electron-enriched regions are located on the Fe and interlayer Ni3 sublattices that dominate the d states near E_F. Full article

The severe heterogeneity of carbonate reservoirs poses a significant challenge to matrix acidizing, making the achievement of uniform stimulation across multiple strata a persistent engineering difficulty. To address this, a numerical simulation program for self-diverting acid (SDVA) in multi-layered rocks was developed based on the two-scale continuum model and the open-source framework FMOT. This study primarily investigates the regulatory effects of heterogeneity intensity and initial temperature on uniform acidizing performance. The results indicate that, compared to conventional HCl, SDVA significantly enhances the uniform acidizing efficacy in low-permeability layers. Furthermore, SDVA induces a unique “competitive propagation” pattern among multi-layered rocks, which is fundamentally distinct from the fluid diversion behavior of HCl. As the formation heterogeneity intensity increases, the resulting wormhole morphology becomes increasingly complex, accompanied by more pronounced inter-layer flow competition. Moreover, unlike HCl, whose flow distribution pattern and wormhole morphology are insensitive to thermal changes, the acidizing performance of SDVA exhibits marked temperature dependence. At lower temperatures, the competitive propagation pattern diminishes significantly; however, as the temperature rises, the inter-layer fluid competition becomes progressively intensified, and this competitive state persists until the ultimate breakthrough of the rock matrix. Full article

Global container liner shipping networks (GCLSNs) underpin world trade, yet their organization is increasingly reshaped by geopolitical fragmentation. Existing studies often model GCLSNs as single-layer networks, overlooking how carriers’ geopolitical affiliations structure both connectivity and disruption risk. This study constructs a weighted carrier–geopolitical multiplex network in which layers are defined by carriers’ geopolitical affiliations and coupled through shared port calls. Structural analysis reveals pronounced asymmetry in layer size, cohesion, and inter-layer dependence, with overlap concentrated in a limited set of shared hubs. Using the Red Sea crisis as an empirical stress-test scenario, we develop a load–capacity propagation model, incorporating intra-layer load redistribution, rerouting to substitute shared hubs, and inter-layer resource squeeze at same-port layer copies. Results show that direct losses concentrate in corridor-exposed layers, while indirect losses propagate selectively through bridge hubs, especially Singapore, Shanghai, Shenzhen, and Port Klang. Sensitivity analysis indicates nonlinear amplification when low tolerance, strong inter-layer squeeze, and elevated rerouting pressure coincide. These findings show that multiplexity does not imply resilience by itself; cross-layer connectivity buffers disruption only when spare capacity is distributed but amplifies vulnerability when it converges on a narrow set of shared hubs. The paper contributes a carrier–geopolitical perspective to shipping network analysis and a dynamic framework for studying disruption propagation in complex logistics systems. Full article

The frictional behavior and stability of skid shoe systems are critical to the safety and controllability of walking-type incremental launching for long-span steel truss bridges. Therefore, this study investigates friction control mechanisms and multilayer pad stability through two tests: (1) skid shoe tests to evaluate low-friction performance, sliding stiffness, and the stability of stacked pad assemblies, and (2) interface friction tests to examine the frictional behavior of different material combinations intended to provide high-friction restraint. The results show that Modified Graphene-Enhanced (MGE) plates, when combined with grease and stainless steel, reduce the friction coefficient to 0.017–0.074. High-stack pad assemblies (6–16 layers) exhibited a progressive interlayer slip, with cumulative displacements exceeding the allowable limit, leading to instability; anti-slip measures such as shear keys and segmented restraints were recommended. A load-dependent sliding stiffness relationship, y = 57.46 + 0.00886x, was established to characterize the variation in nominal sliding stiffness with vertical load. The findings provide experimental data and engineering recommendations for the design and operation of skid shoe systems in heavy-load incremental launching applications. The proposed criteria and regression model are applicable to the tested pad geometry, interface configuration, and loading conditions investigated in this study. Full article

Three-dimensional concrete printing (3DCP) has emerged as a promising digital construction technology that reduces material waste, eliminates formwork, and enables complex geometries. However, its sustainability remains constrained by the extensive use of ordinary Portland cement (OPC) and natural aggregates. This review comprehensively evaluates waste utilization in extrusion-based 3D printed concrete, classifying applications into three pathways: cement replacement in OPC-based systems, waste-derived precursors in alkali-activated/geopolymer binders, and fine aggregate replacement. Industrial, agricultural, and marine wastes are assessed regarding their effects on rheology, printability, mechanical performance, interlayer bonding, and durability. The reviewed literature investigated waste incorporation levels reaching up to 50% for cement replacement, up to 70% for alkali-activated/geopolymer systems, and up to 100% for aggregate replacement, depending on the material type and application pathway. Industrial wastes, particularly fly ash, slag, silica fume, and metakaolin, represent the most mature materials and generally improve printability and long-term performance. Agricultural and marine wastes show promising sustainability potential but remain insufficiently investigated. Despite encouraging laboratory-scale results, challenges related to material variability, early-age performance, standardization, and scalability continue to limit practical implementation. The review identifies critical research gaps and outlines future directions for developing sustainable and field-ready 3DCP technologies. Full article

Graphene and carbon nanotube (CNT) membranes are promising for filtration, desalination, and water treatment, yet their performance requires the joint interpretation of their architecture, nanoconfined transport, selectivity, fouling, swelling, defects, stability, and operating conditions. Here, GCMembrane-LLM was developed as an evidence-grounded domain-specific large language model. A curated 582-paper corpus generated 12,208 cleaned membrane-specific question–answer pairs for Low-Rank Adaptation (LoRA)-based supervised fine-tuning of Llama-3.1-8B-Instruct, and retrieval-augmented generation provided article-title and page-level traceability. GCMembraneBench included 100 application-oriented questions on graphene oxide (GO) membranes, CNT membranes, GO/CNT hybrids, and cross-material reasoning. Under direct answering without retrieval context, the anonymized and shuffled automatic evaluation showed that GCMembrane-LLM achieved a mean weighted score of 4.237/5.0, exceeding Llama-3.1-8B-Instruct and Doubao-1.5-lite. A stratified 30-question blinded manual assessment showed the same ranking. The application cases further yielded membrane science conclusions: CNT-assisted GO/CNT transport should be evaluated with dispersion, interfacial compatibility, defects, and stability; GO desalination depends on swelling control, interlayer spacing, and defect suppression; and CNT high flux requires joint examination of pore diameter, entrance chemistry, hydration barriers, ion rejection, and operating conditions. GCMembrane-LLM supports source-traceable evidence organization and preliminary hypothesis formulation before experimental validation. Full article

Magnesium–rich environments are frequently encountered in cementitious systems, including the use of high–Mg raw materials in clinker production, cement–clay interfaces relevant to nuclear waste disposal, and exposure of cement–based materials to seawater, where progressive decalcification can substantially alter the structure and durability of calcium aluminosilicate hydrate (C–A–S–H) phases. In this study, density functional theory (DFT) calculations were employed to investigate the combined effects of interlayer and intralayer partial decalcification, Mg²⁺ substitution, and reinforcement with epoxy– and hydroxyl–functionalized reduced graphene oxide (rGO) on the structural stability and elastic properties of alkali charge–balanced C–A–S–H under dry and hydrated conditions. Adsorption–energy calculations reveal thermodynamically favorable interactions between functionalized rGO and silicate hydrate species in the presence of Mg²⁺, with hydroxyl/rGO promoting stronger interfacial stabilization and epoxy/rGO preserving greater graphene lattice integrity. The results demonstrate that Mg²⁺ substitution together with rGO intercalation generally enhances the mechanical response of partially decalcified structures through structural densification and interfacial cohesion. Relative to dry systems, hydration further improves elastic performance, increasing Young’s modulus and bulk modulus by 1–11% and 4–19%, respectively, for interlayer decalcified nanocomposites, while intralayer configurations exhibit stronger but model–dependent enhancements of up to ≈22% and ≈33%. Compared with untreated systems, rGO–treated nan–composites exhibit enhanced stiffness, with Young’s modulus and bulk modulus increasing by up to ≈22% and ≈15%, respectively. Overall, these findings provide atomistic insights into stabilization mechanisms in partially decalcified alkali charge–balanced C–A–S–H systems and identify Mg²⁺–rGO incorporation as a promising strategy for mitigating decalcification–induced degradation in durable low–carbon cementitious nanocomposites. Full article

Hydraulic fracture height growth in thin sandstone–mudstone interbeds is often limited by bedding interface failure and multi-cluster stress interference. In this study, a coupled fracture–matrix interface finite element model was developed for the He-8 sandstone–mudstone interbeds in the Sulige Gas Field and validated against previously published true triaxial hydraulic fracturing experiments. The simulations indicate that vertical–horizontal stress difference (VSD; the difference between overburden stress and minimum horizontal stress within a layer) promotes fracture-height growth, whereas interlayer stress difference (ISD; the minimum horizontal stress contrast between adjacent layers) acts as a stress barrier that promotes bedding interface shear failure and arrests vertical growth. For the investigated reservoir configuration, each 4 MPa increase in VSD increased fracture height by approximately 1.5 m in the three-cluster case and 1.8 m in the four-cluster case, whereas each 2 MPa increase in ISD reduced the average fracture height by approximately 4.0 m in the three-cluster case and 3.5 m in the four-cluster case. Under moderate ISD, increasing the fluid viscosity was more effective than increasing the injection rate alone, although the benefit depended on cluster number and interface failure state. These results clarify how stress contrast, interface strength, and multi-cluster stress shadows jointly control cross-layer fracture propagation in thin interbedded reservoirs. Full article

The performance and durability of lithium metal solid-state batteries are governed by the dynamic evolution of the lithium/solid-electrolyte (Li/SSE) interface, where electrochemical reactions, mass transport, and mechanical constraints are intrinsically coupled. This review presents an integrated electro-chemo-mechanical framework that links interfacial stripping dynamics to distinct degradation regimes controlled by current density, stack pressure, and thermal activation. We show that stable cycling emerges only within a narrow flux-balance window in which lithium creep and vacancy diffusion compensate stripping-induced volume loss without triggering electrolyte fracture or filament penetration. By synthesizing recent experimental, modeling, and materials engineering advances, the review maps the transitions between void-dominated instability, pressure-assisted stabilization, and stress-limited failure. Particular emphasis is placed on adaptive pressure strategies, compliant interlayer design, and microstructural interface engineering as pathways to expand the operational stability window. The analysis highlights that interfacial stability is not solely a materials property but a systems-level outcome arising from coupled electro-mechanical boundary conditions and temperature-dependent transport processes. This perspective provides design principles for developing next-generation solid-state batteries capable of stable high-rate cycling and long-term reliability. Full article

This study investigates graphene oxide/carboxymethyl cellulose composite membranes containing 3 wt.% graphene oxide. The influence of the carboxymethyl cellulose content on the structural organization, mechanical properties, electrical resistivity, and humidity-dependent conductivity was systematically analyzed using Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, tensile testing, and electrical measurements. Fourier transform infrared spectroscopy indicated intermolecular interactions between graphene oxide and carboxymethyl cellulose functional groups. X-ray diffraction analysis showed gradual inter-layer expansion from 0.71 to 0.87 nm together with crystallite size reduction after polymer incorporation. Scanning electron microscopy observations demonstrated the increasing structural uniformity and polymer encapsulation of graphene oxide sheets with the increasing carboxymethyl cellulose content. Mechanical testing revealed improvement in the tensile strength from 6.6 to 17.8 MPa with the increasing carboxymethyl cellulose concentration. Simultaneously, the dry-state electrical resistivity increased from 5.8 × 10⁶ to 2.32 × 10⁷ Ω·m due to increasing dielectric separation between graphene oxide domains. Humidity-sensing experiments demonstrated reversible resistance changes in the 20–90% relative humidity range, associated with proton-assisted conduction through adsorbed water layers. The obtained results demonstrate that polymer incorporation strongly influences both the structural organization and electrophysical behavior of graphene oxide/carboxymethyl cellulose composite membranes. Full article

Twist-angle engineering in van der Waals bilayers enables excitonic and valley phenomena that are not accessible in naturally stacked crystals. In a dual-gated $3^{\circ }$ twisted bilayer WSe₂ device, low-temperature polarization-resolved photoluminescence spectroscopy reveals a pronounced Stark shift of the interlayer exciton, yielding an effective electron–hole separation of 0.26 nm and indicating a strongly hybridized interlayer excitonic state. The degree of circular polarization (DOCP) is strongly doping-dependent but only weakly affected by the vertical electric field: at zero magnetic field, the DOCP is about 30% in the electron-doped regime and about 18% in the hole-doped regime. An out-of-plane magnetic field of 9 T sharpens this contrast to about 35% and 13%, respectively, suggesting distinct intervalley depolarization dynamics in the two doping regimes. Together, these results show that an electric field primarily tunes exciton energy, whereas doping and a magnetic field control valley polarization, highlighting small-angle twisted bilayer WSe₂ as a promising platform for tunable excitonic and valley-optoelectronic functionalities. Full article

The successful application of extrusion-based 3D-printed geopolymer mortars largely depends on precursor chemistry, activator composition, mixture proportions, and fresh-state behavior, which is highly sensitive to time-dependent structural build-up. This review examines the relationships among mix design, geopolymerization chemistry, rheological properties, and printability requirements for 3D-printed geopolymer mortars. Particular emphasis is placed on the effects of precursor type, alkaline activator characteristics, liquid-to-solid ratio, additives, and fibers on flowability, yield stress, viscosity, extrudability, buildability, shape retention, and interlayer bonding. The review further discusses how geopolymerization kinetics influence the evolution of fresh-state properties, the printable time window, and the transition from extrusion to structural stability. In addition, early-age performance is evaluated in terms of setting behavior, green strength development, and layer-interface integrity. Current challenges, including the lack of standardized test methods, limited comparability among published studies, and the complex coupling between material design and process parameters, are also highlighted. Finally, the review identifies key research gaps and proposes future directions for developing robust, printable, and sustainable geopolymer mortar systems for additive manufacturing in construction. Full article