Search Results (923)

The paper presents a method for obtaining partially degradable capillary membranes from a polyethersulfone/polycaprolactone (PES/PCL) mixture. PES/PCL membranes were obtained by the phase inversion technique with dry/wet spinning and then subjected to controlled degradation in an alkaline environment (1 M NaOH) and simulated body fluid (SBF with pH 7.4) using the flow method. The aim of the work was to select and apply a degradable, non-toxic, simple polymer as a removable component of the membrane structure. The degradable component of the membranes was PCL, the gradual hydrolysis of which was aimed at increasing the porosity and improving the transport properties of the membranes during operation. The membrane properties, such as hydraulic permeability coefficient (UFC), retention coefficient, and structural morphology, were assessed using scanning electron microscopy (SEM) before and after degradation. Analysis of SEM images performed with MeMoExplorer^TM software showed an increase in the proportion of large pores (above 300 µm²) and total porosity of the membranes after degradation in NaOH and SBF. Low instability factor (<0.25) for all samples, both before and after degradation, confirms the good repeatability of the membrane structure. An increase in the UFC was observed, while the retention coefficients did not change significantly in the case of membranes after the etching process. The degradation of the PCL component in the membrane was assessed using the weight method. Measurements of the membrane mass loss before and after degradation confirmed the removal of over 50 wt.% of the PCL component in SBF and 70 wt.% in NaOH from the tested membranes, which resulted in an increase in permeability due to increased membrane porosity. The results indicate the possibility of using such structures as functional, partially self-regulating membranes, potentially useful in biomedical and environmental applications. Full article

We present a multifunctional, reconfigurable terahertz metasurface built from dual split-ring resonators combining photosensitive silicon and metallic elements. By hybridizing structural and Pancharatnam–Berry phase control, the device achieves spin-decoupled manipulation of circularly polarized wavefronts and an optical, light-intensity-driven reconfiguration mechanism. Using spatially encoded bifocal responses, we implement two two-input/two-output logic modules (OR-XOR and AND-NAND), and full-wave simulations verify the expected truth-table behaviors; additionally, a spin- and intensity-dependent hologram produces four distinct far-field images under different input conditions. At the selected working point (≈0.95 THz), the design exhibits a strong cross-polarization response (cross-polarized reflection amplitude > 0.7), demonstrating a viable route toward chip-scale, integrated terahertz logic and multifunctional imaging devices. Full article

As global obesity rates rise, cardiovascular diseases increase, and stress-related issues become more severe. This increases the public awareness of health and exercise. However, existing spinning fitness equipment lacks personalized customization for individual needs. To address this, we developed a smart customizable spinning system that enables health monitoring, central computation, flywheel, voice interaction, notification, and query subsystems. Users can set fitness goals based on their personal needs, monitor workout data via sensors, and utilize voice interaction and control to track their exercise status in real time. The system notifies users of workout progress through a buzzer and message queuing telemetry transport, while the Web interface provides access to past workouts and health records. Additionally, the system supports bilingual functionality (Chinese and English), allowing users to operate it in their preferred language, enhancing global usability. Full article

The discharge of printing and dyeing wastewater has become a key concern in global water pollution control due to its high pollutant concentration, dark color, refractory biodegradability and toxic characteristics. Photoelectrocatalytic (PEC) technology has gained widespread attention as it can effectively treat refractory organic pollutants. In this study, titanium dioxide (TiO₂)–bismuth vanadate (BiVO₄) composite materials were synthesized through the sol–gel/solvothermal hybrid method, and layered heterojunction structures were fabricated via sol–gel precursor preparation followed by spin-coating deposition. The PEC degradation efficiency of rhodamine B (RhB) was systematically evaluated under varying operational conditions in the presence of TiO₂-BiVO₄. The four-layer BiVO₄/four-layer TiO₂ material showed the optimal catalytic activity among the tested structures, achieving an 80.3% removal of RhB under an applied bias of 4 V and illumination intensity of 14,000 lx. Through the equilibrium adjustment of the Fermi levels, the type Ⅱ heterostructure was formed. Moreover, superoxide radical (O₂⁻) was identified as the predominant reactive oxygen species driving the degradation mechanism. Mechanistic analysis revealed that RhB degradation was accomplished through deethylation, benzene ring cleavage, and subsequent ring-opening mineralization. This study prepared an efficient PEC material, which provides a theoretical basis for the PEC treatment of printing and dyeing wastewater. Full article

Aircraft spin, a nonlinear phenomenon dominated by unsteady aerodynamics, is difficult to predict. This article proposes a novel approach using Hankel Dynamic Mode Decomposition with Control (HDMDc) to identify an aircraft plant model for spin motion directly from measurement data. A key challenge in real-world data-driven modeling is addressing noise in both input and output measurements, often termed errors in variables (EIV). The standard HDMDc does not account for the distinct noise characteristics of different sensors. To overcome this, modifications are proposed to the standard HDMDc algorithm using EIV approaches: total least squares and bias-eliminating least squares. The proposed algorithms are validated first with a simple nonlinear dynamical system exhibiting limit cycle oscillation. Further, the methodology is applied to the simulated steady spin of the T-2 aircraft and the oscillatory spin motion of the F-18 aircraft. It is demonstrated that models identified using HDMDc with the EIV approach predicted spin trajectories with high goodness-of-fit values, even for unseen control inputs and initial conditions that differed from the training data. Specifically, the predicted trajectories had a FIT% close to 90% in most cases, with the worst-case FIT% being 38%. In contrast, the standard HDMDc algorithm’s predicted trajectory was not even visually close to the actual system trajectory, highlighting the significant improvement of the modified approach. Full article

Heme enzymes that bind and reduce O₂ are susceptible to poisoning by NO. The high reactivity and affinity of NO for ferrous heme produces stable ferrous-NO complexes, which in theory should preclude O₂ binding and turnover. However, NO inhibition is often competitive with respect to O₂ and rapidly reversible, thus providing cellular and organismal survival advantages. This kinetic paradox has prompted a search for mechanisms for reversal and hence resistance. Here, I critically review proposed resistance mechanisms for NO dioxygenase (NOD) and cytochrome c oxidase (CcO), which substantiate reduction or oxidation of the tightly bound NO but nevertheless fail to provide kinetically viable solutions. A ferrous heme intermediate is clearly not available during rapid steady-state turnover. Reversible inhibition can be attributed to NO competing with O₂ in transient low-affinity interactions with either the ferric heme in NOD or the ferric heme-cupric center in CcO. Toward resolution, I review the underlying principles and evidence for kinetic control of ferric heme reduction via an O₂-triggered ferric heme spin crossover and an electronically-forced motion of the heme and structurally-linked protein side chains that elicit electron transfer and activate O₂ in the flavohemoglobin-type NOD. For CcO, kinetics, structures, and density functional theory point to the existence of an analogous O₂ and reduced oxygen intermediate-controlled electron-transfer gate with a linked proton pump function. A catalytic cycle and mechanism for CcO is finally at hand that links each of the four O₂-reducing electrons to each of the four pumped protons in time and space. A novel proton-conducting tunnel and channel, electron path, and pump mechanism, most notably first hypothesized by Mårten Wikström in 1977 and pursued since, are laid out for further scrutiny. In both models, low-energy spin-orbit couplings or ‘spintronic’ interactions with O₂ and NO or copper trigger the electronic motions within heme that activate electron transfer to O₂, and the exergonic reactions of transient reactive oxygen intermediates ultimately drive all enzyme, electron, and proton motions. Full article

Energy policies and economies of scale have promoted the expansion of renewable energy sources, leading to the displacement of conventional generation units and a consequent reduction in system inertia. Low inertia amplifies frequency deviations in response to generation–load imbalances, increasing the risk of load shedding and service interruptions. To address this issue, this paper proposes a coordinated control strategy based on neuro-fuzzy networks, applied to a hybrid energy storage system (HESS) composed of batteries and supercapacitors. The controller is designed to simultaneously emulate virtual inertia and implement virtual droop control, thereby improving frequency stability and reducing reliance on spinning reserve. Additionally, a state-of-charge (SOC) management layer is integrated to prevent battery operation in critical zones, mitigating degradation and extending battery lifespan. The neuro-fuzzy controller dynamically coordinates the power exchange both among the energy storage technologies (batteries and supercapacitors) and between the HESS and the conventional generation unit, enabling a smooth and efficient transition in response to power imbalances. The proposed strategy was validated through simulations in MATLAB R2022b using a two-area power system model with parameters sourced from the literature and validated references. System performance was evaluated using standard frequency response metrics, including performance indicators (ITSE, ISE, ITAE and IAE) and the frequency nadir, demonstrating the effectiveness of the approach in enhancing frequency regulation and ensuring the operational safety of the energy storage system. Full article

The photonic spin Hall effect (PSHE) has emerged as a powerful metrological approach for precision measurements. Dynamic manipulation of PSHE through external stimuli could substantially expand its applications. In this work, we present a simple and active modulation scheme for PSHE in a surface plasmon resonance (SPR) structure by exploiting electric-field-tunable refractive indices of electro-optic materials. By applying an electric field, the enhancement of PSHE spin shifts is observed, and the dual-field control can further amplify these spin shifts through synergistic effects in this SPR structure. Notably, various operation modes of external electric field enable the real-time switching between two high-performance sensing functionalities (refractive index detection and angle measurement). Therefore, our designed PSHE sensor based on SPR structure with a simple structure of only three layers not only makes up for the complex structure in multi-functional sensors, but more importantly, this platform establishes a new paradigm for dynamic PSHE manipulation while paving the way for advanced multi-functional optical sensing technology. Full article

This review summarizes the recent advances in the application of nanomaterial coatings in optical fiber sensors, with a particular focus on deposition techniques and the research progress over the past five years in humidity sensing, gas detection, and biosensing. Benefiting from the high specific surface area, abundant surface active sites, and quantum confinement effects of nanomaterials, advanced thin-film fabrication techniques—including spin coating, dip coating, self-assembly, physical/chemical vapor deposition, atomic layer deposition (ALD), electrochemical deposition (ECD), electron beam evaporation (E-beam evaporation), pulsed laser deposition (PLD) and electrospinning, and other techniques—have been widely employed in the construction of functional layers for optical fiber sensors, significantly enhancing their sensitivity, response speed, and environmental stability. Studies have demonstrated that nanocoatings can achieve high-sensitivity detection of targets such as humidity, volatile organic compounds (VOCs), and biomarkers by enhancing evanescent field coupling and enabling optical effects such as surface plasmon resonance (SPR), localized surface plasmon resonance (LSPR), and lossy mode resonance (LMR). This paper first analyzes the principles and optimization strategies of nanocoating fabrication techniques, then explores the mechanisms by which nanomaterials enhance sensor performance across various application domains, and finally presents future research directions in material performance optimization, cost control, and the development of novel nanocomposites. These insights provide a theoretical foundation for the functional design and practical implementation of nanomaterial-based optical fiber sensors. Full article

Developing perovskite solar cells (PSCs) with both high performance and long-term stability remains a critical challenge and research focus in the field of photovoltaic devices. Herein, we report a multi-step spin-coating strategy for high-efficiency 2D/3D perovskite heterojunction solar cells by sequentially depositing low-concentration 3-pyridine methylamine iodine solutions onto 3D perovskite films. This approach enables controlled Ostwald ripening and forms graded 2D/3D heterointerfaces rather than insulating capping layers, yielding a champion device with a PCE of 22.7%, significantly outperforming conventional 2D/3D planar counterparts. The optimized structure exhibits enhanced carrier extraction, suppressed recombination, and exceptional humidity stability; the hydrophobic structure further enabled >85% initial efficiency retention after 800 h at 45% relative humidity (RH) for target devices. This study establishes a novel research paradigm for developing high-performance and stable 2D/3D perovskite solar cells through gradient dimensionality engineering. Full article

The increasing penetration of photovoltaic (PV) generation in power systems is progressively displacing traditional synchronous generators, leading to a significant reduction in the system’s equivalent inertia. This decline undermines the system’s ability to withstand rapid frequency variations, adversely affecting its dynamic stability. In this context, battery energy storage systems (BESS) have emerged as a viable alternative for providing synthetic inertia and enhancing the system’s response to frequency disturbances. This paper proposes the design and implementation of an adaptive fuzzy logic controller aimed at frequency regulation in PV-BESS systems. The controller uses frequency deviation (Δf), rate of change of frequency (ROCOF), and battery state of charge (SOC) as input variables, with the objective of improving the system’s response to frequency variations. The controller’s performance was evaluated through simulations conducted in the MATLAB environment, considering various operating conditions and disturbance scenarios. The results demonstrate that the proposed controller achieves the lowest maximum frequency deviation across all analyzed scenarios when the initial SOC is 50%, outperforming other comparative methods. Finally, compliance with primary frequency regulation (PFR) was verified in accordance with the Technical Procedure PR-21 related to spinning reserve, issued by the Peruvian Committee for Economic Operation of the System. Full article

The interfacial Dzyaloshinskii–Moriya interaction (DMI) plays a pivotal role in stabilising and controlling the motion of chiral spin textures, such as Néel-type bubble domains, in ultrathin magnetic films—an essential feature for next-generation spintronic devices. In this work, we investigate domain wall (DW) dynamics in magnetron-sputtered Ta(3 nm)/Pt(3 nm)/Co(1 nm)/RuO₂(1 nm) [Ru(1 nm)]/Pt(3 nm) multilayers, benchmarking their behaviour against control stacks. Vibrating sample magnetometry (VSM) was employed to determine saturation magnetisation and perpendicular magnetic anisotropy (PMA), while polar magneto-optical Kerr effect (P-MOKE) measurements provided coercivity data. Kerr microscopy visualised the expansion of bubble-shaped domains under combined perpendicular and in-plane magnetic fields, enabling the extraction of effective DMI fields. Brillouin light scattering (BLS) spectroscopy quantified the asymmetric propagation of spin waves, and micromagnetic simulations corroborated the experimental findings. The Pt/Co/RuO₂ system exhibits a Dzyaloshinskii–Moriya interaction (DMI) constant of ≈1.08 mJ/m², slightly higher than the Pt/Co/Ru system (≈1.03 mJ/m²) and much higher than the Pt/Co control (≈0.23 mJ/m²). Correspondingly, domain walls in the RuO₂-capped films show pronounced velocity asymmetry under in-plane fields, whereas the symmetric Pt/Co/Pt shows negligible asymmetry. Despite lower depinning fields in the Ru-capped sample, its domain walls move faster than those in the RuO₂-capped sample, indicating reduced pinning. Our results demonstrate that integrating RuO₂ significantly alters interfacial spin–orbit interactions. Full article

The precise measuring and control of fiber tension are critically important for enhancing structural and mechanical properties in spinning processes, as tension directly influences orientation, crystallinity, and mechanical properties. However, current tension measurement methods primarily operate offline and lack real-time measuring capabilities. A non-contact fiber tension detection system is introduced to investigate the effects of draw tension and its uniformity on the structure and mechanical properties of polyester fibers. During experiments conducted at a spinning speed of 1200 m/min across different draw ratios, the non-contact system demonstrated strong agreement with the contact tension detector. The results showed that increasing the tension from 34 cN to 164 cN reduced the monofilament diameter from 39.61 µm to 20.35 µm. Simultaneously, the orientation factor nearly tripled, while crystallinity increased from 55.72% to 77.39%. Mechanical testing revealed a 50.96% improvement in breaking strength, rising from 1.57 to 2.37 cN/dtex, accompanied by a significant decrease in elongation at break from 275.55% to 34.95%. However, tension fluctuations, characterized by an average fluctuation coefficient increase from 4.51% to 18.18%, caused diameter inconsistency. These fluctuations also reduced the orientation factor by 10.78%, lowered crystallinity, and substantially deteriorated mechanical properties. These findings underscore the critical importance of real-time, online tension monitoring for ensuring polyester fiber quality and performance during production. Full article

Spintronics, an interdisciplinary field merging magnetism and electronics, has attracted considerable interest due to its potential to transform data storage, logic devices, and emerging quantum technologies. Among the materials explored for spintronic applications, metal oxide nanostructures synthesized via sol–gel methods offer a unique combination of low-cost processing, structural tunability, and defect-mediated magnetic control. This comprehensive review presents a critical overview of recent advances in sol–gel-derived magnetic oxides, such as Co-doped ZnO, La_1−xSr_xMnO₃, Fe₃O₄, NiFe₂O₄, and transition-metal-doped TiO₂, with emphasis on synthesis strategies, the dopant distribution, and room-temperature ferromagnetic behavior. Key spintronic functionalities, including magnetoresistance, spin polarization, and magnetodielectric effects, are systematically examined. Importantly, this review differentiates itself from the prior literature by explicitly connecting sol–gel chemistry parameters to spin-dependent properties and by offering a comparative analysis of multiple oxide systems. Critical challenges such as phase purity, reproducibility, and defect control are also addressed. This paper concludes by outlining future research directions, including green synthesis, the integration with 2D materials, and machine-learning-assisted optimization. Overall, this work bridges sol–gel synthesis and spintronic material design, offering a roadmap for advancing next-generation oxide-based spintronic devices. Full article

To address the challenges of non-axisymmetric tube spinning, this study employs finite element simulations to validate a novel spinning method for right-angle groove tubes. Three forming schemes with distinct roller path geometries were designed and analyzed using Simufact Forming, with 6063-O aluminum alloy tubes serving as the research material. The simulation results indicate that multi-pass forming (Schemes I and II) significantly enhances wall thickness uniformity compared to single-pass forming (Scheme III). Scheme I exhibits optimal performance due to the minimized equivalent stress in the final forming pass. The maximum stress is concentrated at the groove bottom, leading to wall thinning and springback, while the maximum strain occurs at the roller exit point, where metal accumulation causes local wall thickening. Experimental observations confirm the consistency with the simulation results, validating the model’s reliability. This study deepens the understanding of deformation mechanisms in complex groove forming, highlighting the roller path geometry in controlling stress-strain distribution and final product quality. Full article