Search Results (732)

The spatial organization of microscale fillers is critical for macroscopic performance, yet precise control over their distribution and orientation remains a major challenge in direct ink writing. Here, we present an acoustofluidic capillary nozzle that integrates acoustic manipulation into direct ink writing, enabling programmable in situ assembly of functional fillers during extrusion. By coupling a piezoelectric transducer with a commercial glass capillary, stable acoustic standing waves are established within the flow channel, driving suspended filler particles toward pressure nodes via acoustic radiation forces. Simulations and experiments systematically investigate how capillary geometry and material properties influence acoustic energy distribution and particle assembly behavior. In particular, rectangular capillaries generate stable multi-node standing waves, inducing periodic alignment of nickel-coated carbon fibers into ordered conductive bundles. This acoustically programmed microstructure reduces the percolation threshold from 8 wt% to 2 wt% and enhances electrical conductivity by up to 32.1-fold at identical filler contents. Meanwhile, the composites exhibit pronounced anisotropic conductivity and maintain excellent mechanical flexibility, with stable electromechanical performance under 16% bending strain and cyclic loading. This work demonstrates a simple and scalable acoustofluidic nozzle platform for programmable microstructure engineering in direct ink writing, offering new opportunities for fabricating high-performance multifunctional composites. Full article

This study produced and analyzed composite membranes composed of polysulfone (PSf), polyvinylpyrrolidone (PVP) and Metal–Organic Framework (ZIF-8) for treating effluent generated by the Batik industry. The incorporation of ZIF-8 was performed to enhance membrane efficiency. The findings indicated that ZIF-8 markedly enhanced hydrophilicity and pure water flux of membranes. The M-0.5 membrane containing 0.5 g of ZIF-8 demonstrated superior performance, with a water contact angle of 49.4° and a porosity of 83.5%. In contrast, the ZIF-8-free membrane (M-0) displayed a water contact angle and porosity of 66.3° and 76.7%, respectively. These combined characteristics enabled the M-0.5 membrane to achieve the highest pure water flux of 197.1 L m⁻² h⁻¹ at 5 bar. All membranes attained complete total suspended solids (TSS) rejection at 100% efficiency. Turbidity rejection rates ranged from 75% to 92%, whilst color rejection rates ranged from 65.7% to 87.6%. The maximum chemical oxygen demand (COD) rejection observed was 57.9%, achieved by the M-0.25 membrane (0.25 g of ZIF-8) at an operational pressure of 4 bar. Meanwhile, for permeability and hydrophilicity, the ideal loading is 0.5 g of ZIF-8 (M-0.5). This concentration yielded the optimal equilibrium of porosity (83.5%), the minimal water contact angle (49.4°), and the maximal pure water flux (197.1 L m⁻² h⁻¹). Nonetheless, the TDS rejection rate was rather low at 8.0–21.1%. The membrane effectively preserved effluent pH stability between 7.9 and 8.3. The aggregation of ZIF-8 at elevated concentrations diminished mechanical strength and selectivity. Additional optimization is required to equilibrate these performance indicators. Full article

Suspended particulate matter (SPM) is a key environmental driver in aquatic ecosystems and plays a significant role in shaping microbial communities, particularly in sediment-rich rivers. Dam construction alters hydrological regimes and creates distinct SPM gradients; however, the response mechanisms of microeukaryotic plankton communities remain poorly understood. In this study, we used 18S rRNA gene high-throughput sequencing to characterize microeukaryotic plankton communities across riverine, lacustrine, and transitional zones of the Xiaolangdi Reservoir on the Yellow River (China). Our results revealed distinct community compositions in the lacustrine zone, with SPM identified as the primary factor driving community differentiation. Alpha diversity was highest in the riverine zone, while beta diversity differences among zones were dominated by species turnover. Dominant taxa included Cryptophyta (44.71% ± 30.79%), Metazoa (18.98% ± 17.71%), Perkinsea (7.97% ± 9.78%), Chlorophyta (7.06% ± 5.80%), and Dinophyta (6.06% ± 6.73%). Metazoa, Dinophyta, and Phaeophyta were enriched in high-SPM riverine waters, whereas Alveolata dominated low-SPM lacustrine zones. Community assembly was primarily deterministic, governed mainly by homogeneous selection, with stochastic processes exerting stronger influence in riverine zones. Network analysis indicated that riverine zones exhibited more complex and stable networks, lacustrine zones showed higher local but lower global connectivity, and transitional zones displayed stronger interactions but lower stability. These findings advance our understanding of microeukaryotic plankton responses to dam-induced environmental changes and provide a basis for assessing biodiversity impacts in regulated river systems. Full article

In deepwater oil and gas development, conventional well-by-well drilling and completion involve repeated equipment deployment, resulting in low efficiency. The Liza project in the Stabroek Block, Guyana, adopts a batch drilling and completion mode, significantly improving operational efficiency. However, inter-well towage of a suspended riser introduces challenges to riser integrity and safety. This study reviews key technologies in batch drilling and develops a mechanical model for riser hard hang-off using OrcaFlex 11.5 to assess the effects of wave height, wind speed and direction, and towing speed on riser stress and universal joint angular displacement. Simulations under representative Guyana conditions show that riser stress increases with wave height. The most critical scenario occurs when towing against the current with a following wind, where the maximum safe towing speed is 0.80 m/s, governed by angular displacement limits. Additionally, batch operations significantly reduce drilling and connection time and offer environmental benefits. These results provide guidance for optimizing deepwater batch drilling and ensuring towing safety. Full article

A high quality factor, denoted as the Q-factor, is crucial for micromachined disk resonator gyroscopes, commonly referred to as DRGs, to suppress thermomechanical noise and improve bias stability. However, the coupled energy dissipation mechanisms under low-pressure conditions impose significant limitations on further Q-factor enhancement. This paper establishes a rigorous multiphysics damping analysis framework for DRGs and quantitatively investigates the contributions of air damping, thermoelastic damping, and anchor loss. A free-molecular squeeze-film damping model is derived based on kinetic gas theory and molecular energy transfer mechanisms, avoiding the continuous fluid assumption of the classical Reynolds equation, which fails in low-pressure regimes. Due to the highly symmetric ring structure and central anchor design, finite element method simulations reveal an extremely high anchor-loss-limited quality factor, Q_anchor, of approximately 1.85 × 10¹², indicating negligible anchor-induced dissipation. Under an operating pressure of 0.1 Pa, air damping is validated as the absolute dominant energy dissipation mechanism with a gas quality factor, Q_air, of approximately 1.105 × 10⁵, which is significantly lower than the thermoelastic damping quality factor, Q_TED, evaluated at 8.98 × 10⁵. To break the classical trade-off between squeeze-film damping suppression and capacitive drive efficiency, a decoupled gap optimization strategy is proposed. By maintaining the drive electrode gap, gap_e, at 7.2 µm while increasing only the parasitic ring-to-suspended-mass gap, gap_m, to 12 µm, the squeeze-film-damping-limited Q-factor is improved by approximately 25% to 1.381 × 10⁵ without degrading electromechanical coupling efficiency. In addition, the optimal anchor radius is determined to be approximately 160 µm. The proposed framework provides practical design guidance for high-Q DRGs and other MEMS resonant inertial sensors. Full article

In inland river basins, the coupling relationship among water, sediment, and phosphorus is essentially the redistribution of phosphorus carried in the river system, and the presence of plants affects its transport and distribution. Meanwhile, fish are the most important component in river ecosystems, and the transport patterns of water, sediment, and phosphorus directly affect the living environment of fish. This study focuses on the coupling relationship among water–sediment–phosphorus and the suitability of fish habitats. By developing a sediment transport program and constructing a coupled movement model through numerical simulation, combined with the fuzzy mathematical theory, an evaluation model for fish habitat suitability is established to explore the coupling transport patterns of water–sediment–phosphorus near the riverbank plant areas and the distribution characteristics of fish habitats. The study found that the flow velocity near arbor is low and vortex structures exist, and the flow velocity values between the plants in the spanwise direction are high, leading to significant bank erosion. Among them, the erosion near arbor is severe, and the depth of erosion pits on the shallow water side is large. The transport of suspended sediment and phosphorus is closely related to water flow movement. In the spanwise direction between plants, sediment and phosphorus high-concentration areas are layered in a “strip” shape along the flow direction. Turbulent water flow drives the suspension of riverbed sediment and releases high phosphorus flux. Arbors have a significant impact on phosphorus transport, and the diffusion of dissolved phosphorus in pore water in some areas is prone to increase the concentration of phosphorus in the water body. The nitrogen–phosphorus ratio is regularly distributed, and the ratio between plants in the spanwise direction is close to the Redfield value, which is suitable for the growth of phytoplankton. In terms of fish habitats, areas near bank plants are not suitable for the survival of juvenile fish. The suitable areas for fish spawning are mainly distributed between plants in the spanwise direction, and the area is relatively small, but plants can provide emergency shelter. The innovation of this study lies in constructing a coupled movement model of water–sediment–phosphorus and an evaluation model for fish habitat suitability, clarifying the mechanism of plant influence on phosphorus migration in nearshore sediment and the distribution pattern of fish habitat suitability. The research results can provide important theoretical support and practical reference for the management of water environment and aquatic ecosystems in inland river basins. Full article

Fractional differential operators provide an effective approach for modeling complex technological processes, particularly physical phenomena in continuum mechanics characterized by memory and non-local effects. Different types of fractional derivatives require different numerical approximation schemes; in this study, the Caputo and Grünwald–Letnikov derivatives are considered. The aim of this work was to develop and validate a fractional differential model of longitudinal oscillations in a suspended monorail system that accounts for nonlinear and memory-dependent effects. In contrast to classical integer-order approaches, the proposed framework incorporates multiscale surface irregularity effects, including rail roughness, friction, and other disturbances influencing system dynamics, through a fractional-order formulation. A fractional differential mathematical model describing the motion of longitudinal oscillations of a large-sized cargo transported along a suspended monorail is proposed. A numerical algorithm based on finite-difference approximation of fractional operators was developed for its implementation. The scientific contribution lies in integrating multiscale surface irregularity effects into a fractional-order modeling framework to improve the accuracy of dynamic response prediction. Numerical experiments demonstrated the effectiveness of the approach, and the results were validated through comparison with existing models of monorail dynamics. Additionally, statistical validation based on correlation analysis confirmed good agreement with the experimental data. The proposed model can be applied to the design and optimization of suspended transport systems, improving vibration control, reliability, and operational safety under real dynamic loading conditions. Full article

Hybrid carbon nanotube–fullerene architectures provide a controllable setting in which to study irreversibility and information flow in strongly structured quantum environments. We analyze entropy generation in a platform where paramagnetic endohedral fullerenes (PEFs), such as N@C₆₀ and P@C₆₀, are encapsulated inside a suspended carbon nanotube (CNT) resonator, such that selected multi-level PEF spin states define an effective qubit coupled to quantized CNT flexural modes. Motivated by prior work on fullerene-filled CNTs, on spin–phonon manipulation in suspended nanotubes, and on exact phase-space propagators for damped driven oscillators, we formulate a hybrid open-system description that combines a driven quantum Brownian description of the CNT resonator with an effective Jaynes–Cummings type spin–vibrational interaction. The resonator dynamics are represented in phase space through the Wigner function, whose time evolution can be written analytically in terms of the initial Wigner distribution and a Gaussian propagator. This representation makes it possible to separate drive-induced phase space displacement, diffusion, and damping, and to connect these features directly to entropy flow. The coupled spin–mechanical dynamics are then embedded in a Lindblad quantum master equation that includes mechanical damping, spin relaxation, pure dephasing, and thermally activated excitation channels. Within this framework we derive the entropy balance equation—identifying entropy flux and non-negative entropy production—and examine how hybridization between the molecular spin and the nanotube vibration redistributes irreversibility between coherent exchange and dissipative channels. We show that spin–phonon coupling enhanced by a magnetic field gradient, resonant driving, and moderate thermal occupation can produce identifiable crossovers between entropy–production regimes dominated by the oscillator and those dominated by the spin. The resulting framework provides a quantitative basis for using CNT–PEF hybrids as nanoscale platforms for studying nonequilibrium quantum thermodynamics, decoherence, and information loss in structured vibrational environments. Full article

Various hydraulic automatic gates play an important role in water resources regulation. This study proposes a novel suspended hydraulic automatic control gate for tidal marine energy generation with adaptive one-sided flow-through characteristics. To evaluate its hydraulic performance and regulation mechanism, model experiments were conducted in a laboratory flume under different upstream and downstream water levels and discharge conditions. Gate opening states, hydraulic parameters, and flow field structures were obtained, while computational fluid dynamics simulations were used to reproduce and analyze the experimental flow field. The results show that the gate opening angle and water level jointly control the discharge capacity, and significant differences exist in the flow structure and discharge behavior between free and submerged outflow conditions. The numerical model further reveals vortex structures, velocity stratification, and gas–liquid two-phase distributions near the gate. Variations in gate structural parameters, discharge, and downstream water level significantly affect moment equilibrium, flow regime, and discharge capacity. The proposed discharge formula effectively predicts variations in gate flow and force characteristics under different hydraulic conditions, showing good applicability and engineering value. The suspended hydraulic automatic control gate has a simple structure, strong adaptability, and promising potential for tidal water regulation and engineering applications. Full article

To address delayed roof fracture, severe stress concentration, and strong strata pressure under thick–hard roof conditions, this study investigated the 1014 mining face of Yushuquan Coal Mine. A staged thick-plate model incorporating boundary-condition degradation was established based on Mindlin–Reissner thick-plate theory to analyze the deformation and stress redistribution characteristics of the thick–hard roof during mining. The evolution mechanism of the stress-concentration shell was systematically studied through theoretical analysis, physical simulation, numerical simulation, and field application. The results show that, with mining advancement, the boundary constraints of the thick–hard roof gradually evolve from four-sided clamped support to four-sided simply supported conditions. Meanwhile, the high-stress zone migrates from the goaf boundary toward the central suspended roof region. The stress-concentration shell undergoes a dynamic process of formation, expansion, failure, and reconstruction, and its instability is the main driving mechanism of large-scale roof caving. The plastic zone expands upward in an inverted funnel shape, while acoustic emission signals increase significantly before roof instability and exhibit strong precursor characteristics. Based on the evolution characteristics of the stress-concentration shell, a three-stage coordinated blasting technology was proposed to regulate the overburden load-bearing structure. Field application shows that this method effectively reduces suspended roof distance, caving block size, surrounding rock deformation, and hydraulic support pressure, thereby improving roof stability and mining safety. The results provide theoretical and engineering references for stability control of thick–hard roofs under similar mining conditions. Full article

ASP flooding wastewater contains crude oil, suspended solids, anionic polymers and surfactants, with high viscosity, high zeta potential, difficult demulsification, flocculation and slow separation and sedimentation. In order to solve the problem of wastewater treatment of ASP flooding in oil fields, a magnetic branched core was prepared from ethyl silicate (TEOS), nano Fe₃O₄ and aminopropyl triethoxysilane (APTES), and then reacted with polyamine and methyl acrylate to synthesize the magnetic hyperbranched molecule FSNMN with demulsification ability. Using acrylamide (AM), acryloxyethyl trimethylammonium chloride (DAC) and maleic anhydride (MA) as raw materials, cationic polymer long chain (CAMHA) with flocculating properties was synthesized and grafted with hyperbranched molecules. The demulsification flocculation ability of the product regarding ASP flooding wastewater was evaluated, and the demulsification flocculation mechanism was summarized. The results showed that the average molecular weight of 3-FSNMN₄-C was 4.7 million, the cationic degree was 20.5%, and the saturation magnetization was 20 EMU/g. The removal rate of oil and suspended solids was 93.82% and 91.95% respectively when the simulated sewage was treated by magnetic field for 30 min. Magnetic hyperbranched star chain polymer provides a solution to the serious ecological environment problems caused by ASP flooding. Full article

This paper examines the social and political consequences of parenting with a conviction for a sexual offence in contemporary Britain. We argue that the systems governing people labelled “sex offenders” operate in ways that exceed what Michel Foucault described as biopolitical governance. While biopolitical frameworks have often been interpreted as oriented toward the optimisation and management of life, including through practices of rehabilitation and reintegration, contemporary punishment bureaucracies frequently foreclose these possibilities in practice. For many parents, redemption is not simply delayed but structurally denied, leaving their citizenship permanently uncertain. Drawing on collaborative, reflexive phenomenology, we develop the concept of cleft identity to describe this condition. Parenting is typically understood as a key site of responsible citizenship, centred on the care and protection of life. Yet parents with sexual offence convictions remain subject to ongoing surveillance, disclosure and stigma, marking them as permanently suspect. They are therefore required to perform the responsibilities of “good” parenting while simultaneously treated as moral outsiders. We argue that this tension produces a form of suspended citizenship in which stigma operates not simply as social reaction but as a mechanism of governance. The paper develops this argument through a theoretically driven, collaborative phenomenological case study intended for analytic illumination rather than empirical generalisation. Full article

Under green mine construction and efficient resource utilization, non-pillar mining has been increasingly applied. However, surrounding rock control remains difficult in traditional gob-side entry retaining under large mining height conditions. To address this problem, a cooperative control method combining roof cutting and pressure relief with a pre-placed backfill strip for coal pillar replacement is proposed. Taking the 15,108 and 15,110 working faces of Wangzhuang Coal Industry as the engineering background, a mechanical model and FLAC3D simulations were used to analyze the effects of roof cutting height and backfill strip width. The results show that roof cutting shortens the goaf-side suspended roof, weakens lateral abutment pressure, and improves the stress state of the strip. When the roof cutting height increases from 11 m to 13 m, the peak vertical stress of the strip decreases from 16.2 MPa to 13.9 MPa, with a reduction of 14.2%. When the strip width increases from 1.0 m to 1.5 m, the peak stress decreases by about 12.0%. Thus, the reasonable roof cutting height and strip width are determined to be 13 m and 1.5 m. Field monitoring shows maximum roof-to-floor and rib-to-rib convergences of 178.5 mm and 143.5 mm, respectively, with no obvious strip instability. Full article

Solanum lycopersicum is highly sensitive to water deficits, which negatively affect photosynthesis and increase oxidative stress. Although chitosan nanoparticles (ChNPs) offer a sustainable solution, research on their effects on this species is scarce. This study evaluated whether ChNPs mitigate the physiological and biochemical effects of water deficit on S. lycopersicum seedlings. Thirty-day-old seedlings were grown under greenhouse conditions, and two irrigation levels were established: 80% of substrate water-holding capacity (well-watered, WW), and 50% of water-holding capacity (mild-to-moderate water deficit, WD). Spherical ChNPs with a size of 39.52 ± 10.9 nm were suspended in 1% acetic acid and foliar-applied at 0, 60, or 120 mg L⁻¹. After 10 days, biomass accumulation, chlorophyll fluorescence parameters (F_v′/F_m′, ΦPSII, and ETR), gas exchange, and non-enzymatic antioxidant traits were determined. Even under this early-stage stress regime, water deficit significantly reduced shoot and root biomass, net photosynthesis, and stomatal conductance, while increasing lipid peroxidation. Foliar application of ChNPs, particularly at 60 mg L⁻¹, restored dry matter production and improved photochemical efficiency and electron transport rate by 14%; likewise, net CO₂ assimilation increased by 11.7%. In addition, this dose enhanced antioxidant activity and total phenols by 66% and 1.6-fold, respectively. ChNPs at 60 mg L⁻¹ mitigated the effects of WD in S. lycopersicum by increasing antioxidant and photosynthetic performances. Nevertheless, additional molecular studies, including enzymatic antioxidant characterization and compatible solute profiling, are required to elucidate the mechanisms involved. Full article

With the increased extraction thickness in fully mechanized top-coal caving faces in extra-thick coal seams, the caved gangue in the goaf is unable to effectively support the roof, resulting in aggravated deformation of the pre-driven withdrawal channel. Taking the No. 221304 working face in the No. 13 coal seam of Xiaojiawa Coal Mine as the engineering background, this study combined theoretical analysis, numerical simulation, and field measurement to investigate the effects of the top-coal caving stopping position, suspended roof length, and presplitting roof cutting on the stress and deformation of the rock surrounding the withdrawal channel. The results indicate that the convergence of the roof and floor and that of the two ribs of the withdrawal channel decrease in a staged manner with the increase in the top-coal caving stopping distance, but increase nonlinearly with the increase in the suspended roof length. With the increase in the presplitting roof-cutting height, the surrounding rock deformation first decreases significantly and then tends to level off. When the roof-cutting height is 30.5 m, the reductions in roof displacement and rib convergence reach 33.46% and 37.76%, respectively. When the roof-cutting height is further increased to 35.0 m, the improvement becomes insignificant. Therefore, the reasonable roof-cutting height for the No. 13 coal seam is determined to be 30.5 m. Field monitoring results show that the convergence of the roof and floor and that of the two ribs of the withdrawal channel are reduced by 41.2% and 36.8%, respectively, and the distance between the stopping line and the terminal mining line is shortened by 15 m. The research results provide a useful reference for determining the top-coal caving stopping position and roof-cutting height, and for improving the stability of the surrounding rock of the support withdrawal channel during the final mining stage of fully mechanized top-coal caving faces with thick and hard roofs in extra-thick coal seams. Full article