Search Results (1,065)

Waste textiles may contain heavy metals, which can originate from dyes, mordants, or other chemical treatments used during manufacturing. To explore the impact of heavy metals on the adsorption properties of activated carbon derived from discarded textiles through pyrolysis and to mitigate heavy metal migration, this study investigated the adsorption behavior of copper-impregnated pyrolytic carbon toward typical pollutants—methylene blue and lead—in simulated dyeing wastewater. Aqueous copper nitrate was used to impregnate the waste pure cotton textiles (WPCTs) to introduce copper species as precursors for creating additional active sites. The study systematically examined adsorption mechanisms, single and binary adsorption systems, adsorption kinetics, adsorption isotherms, adsorption thermodynamics, and the influence of pH. Key findings and conclusions are as follows: Under optimal conditions, the copper-containing biochar (Cu-BC) demonstrated maximum adsorption capacities of 36.70 ± 1.54 mg/g for Pb(II) and 104.93 ± 8.71 mg/g for methylene blue. In a binary adsorption system, when the contaminant concentration reached 80 mg/L, the adsorption capacity of Cu-BC for Pb(II) was significantly enhanced, with the adsorption amount increasing by over 26%. However, when the Pb(II) concentration reached 40 mg/L, it inhibited the adsorption of contaminants, reducing the adsorption amount by 20%. SEM, XRD, Cu LMM, FTIR and XPS result analysis proves that the adsorption mechanism of methylene blue involves π–π interactions, hydrogen bonding, electrostatic interactions, and pore filling. For Pb(II) ions, the adsorption likely occurs via electrostatic interactions, complexation with functional groups, and pore filling. This study supplements the research content on the copper adsorption mechanism supported by biochar for heavy metal adsorption research and broadens the application scope of biochar in the field of heavy metal adsorption. Full article

Photocatalysis driven by the visible light of solar energy has received considerable attention in the field of environmental remediation and clean energy production. In this work, monomeric sulfonated palladium phthalocyanine (PdPcS) was encapsulated in zeolitic imidazolate frameworks-8 (ZIF-8) crystals (denoted PdPcS@ZIF-8) through electrostatic interaction in the ammonia system, while their photocatalytic activity was well-maintained together with the structural regularity of ZIF-8 crystals. For comparison, a PdPcS/ZIF-8 sample was obtained from the traditional impregnation method. The ¹³C NMR and UV-DRS spectra confirmed the difference between PdPcS@ZIF-8 and PdPcS/ZIF-8 in terms of the chemical environment effect for PdPcS. Under visible light, the optimal PdPcS@ZIF-8 catalyst achieved complete degradation of 0.1 mM bisphenol A in 120 min. It also exhibited excellent stability, retaining 81.5% activity after four cycles, far outperforming the impregnated sample (32.5%) due to effective encapsulation preventing PdPcS leaching. This versatile one-step synthetic strategy is expected to be useful for designing novel macromolecules@MOF composite materials. Full article

With the rapid development of high-voltage DC (HVDC) power systems, accurate measurement of surface electrostatic potential on insulating components has become critical for electric field assessment and insulation reliability. This paper proposes an electrostatic potential sensor based on cantilever micro-vibration modulation, which employs piezoelectric actuators to drive high-frequency micro-vibration of cantilever-type shielding electrodes, converting the static electrostatic potential into an alternating induced charge signal. An electrostatic induction model is established to describe the sensing principle, and the influence of structural and operating parameters on sensitivity is analyzed. Multi-physics coupled simulations are conducted to optimize the cantilever geometry and modulation frequency, aiming to enhance modulation efficiency while maintaining a compact sensor structure. To validate the effectiveness of the proposed sensor, an electrostatic potential measurement platform for insulating components is constructed, obtaining response curves of the sensor at different potentials and establishing a compensation model for the working distance correction coefficient. The experimental results demonstrate that the sensor achieves a maximum measurement error of 0.92% and a linearity of 0.47% within the 1–10 kV range. Surface potential distribution measurements of a post insulator under DC voltage agreed well with simulation results, demonstrating the effectiveness and applicability of the proposed sensor for HVDC insulation monitoring. Full article

Self-powered sensors, leveraging their integrated energy harvesting–signal sensing capability, effectively overcome the bottlenecks of traditional sensors, including reliance on external power resources, high maintenance costs, and challenges in large-scale distributed deployment. As a result, they have become a major research focus in fields such as flexible electronics, smart healthcare, and human–machine interaction. This paper reviews the core technical paths of six major types of self-powered sensors developed in recent years, with particular emphasis on the working principles and innovative material applications associated with frictional charge transfer and electrostatic induction, pyroelectric polarization dynamics, hydrovoltaic interfacial streaming potentials, piezoelectric constitutive behavior, battery integration mechanism, and photovoltaic effect. By comparing representative achievements in fields closely related to self-powered sensors, it summarizes breakthroughs in key performance indicators such as sensitivity, detection range, response speed, cyclic stability, self-powering methods, and energy conversion efficiency. The applications discussed herein mainly cover several critical domains, including wearable medical and health monitoring systems, intelligent robotics and human–machine interaction, biomedical and implantable devices, as well as safety and ecological supervision. Finally, the current challenges facing self-powered sensors are outlined and future development directions are proposed, providing a reference for the technological iteration and industrial application of self-powered sensors. Full article

Large-scale wireless sensor networks with electric field energy harvesters (EFEHs) offer self-powered, eco-friendly, and scalable crop monitoring in hydroponic greenhouses. However, their practical adoption is limited by the low power density of current EFEHs, which restricts the reliable operation of external sensors. To address this challenge, this work presents a noninvasive EFEH assembled with hydroponic leafy vegetables that harvests electric field energy and estimates plant functional traits directly from the electrical response. The device operates through electrostatic induction produced by an external alternating electric field, which induces surface charge redistribution on the leaf. These charges are conducted through an external load, generating an AC voltage whose amplitude depends on the dielectric properties of the leaf. A low-voltage prototype was designed, built, and evaluated under controlled electric field conditions. Two representative species, Beta vulgaris (chard) and Lactuca sativa (lettuce), were electrically characterized by measuring the open-circuit voltage (VOC) and short-circuit current (ISC) of EFEHs. Three regression models were developed to determine the relationship between foliar moisture content (FMC) and fresh mass with electrical parameters. Empirical results disclose that the plant functional traits are critical predictors of the electrical output of EFEHs, achieving coefficients of determination of $R^2=0.697$ and $R^2=0.794$ for each species, respectively. These findings demonstrate that EFEHs can serve as self-powered, noninvasive indicators of plant physiological state in living leafy vegetable crops. Full article

Mountaintop towers are highly exposed to self-initiated upward lightning flashes. Accurate estimation of their effective height—the equivalent flat-ground height yielding the same lightning exposure—is essential for reliable exposure assessment, for interpreting and calibrating measurement data at instrumented mountaintop towers, and for comparison with established protection guidelines. This study applies a two-step numerical framework that couples finite-element electrostatic simulations with a leader-inception and propagation model for representative tower–terrain configurations reflecting reference instrumented mountaintop sites in lightning research. For each configuration, the stabilization field, the minimum background electric field enabling continuous upward leader propagation to the cloud base, is determined, from which effective heights are obtained. The simulated results agree with the analytical formulation of Zhou et al. (within ~10%), while simplified or empirical approaches by Shindo, Eriksson, and Pierce exhibit larger deviations, especially for broader mountains. A normalized analysis demonstrates that the tower-to-mountain slenderness ratio (h/a) governs the scaling of effective height, following a power-law dependence with exponent −0.17 (R² = 0.94). This compact relation enables direct estimation of effective height from geometric parameters alone, complementing detailed leader-inception modeling. The findings validate the proposed physics-based framework, quantify the geometric dependence of effective height for mountaintop towers, and provide a foundation for improving lightning-exposure assessments, measurement calibration and design standards for elevated structures. Full article

This study evaluates the influence of four unmanned aerial vehicle (UAV) spray nozzle geometries—flat-fan, hollow-cone, air-induction, and ultra-fine electrostatic—on water and pesticide use, canopy coverage, and greenhouse gas emissions in PB-112 rice under field conditions in Saharanpur, India. Across six farms (n = 6), ultra-fine nozzles achieved the greatest reductions in water (41%) and pesticide (43%) volumes, yielding direct pump energy savings of 737 kWh ha⁻¹ and 369 kg CO₂e ha⁻¹, plus further indirect savings from manufacturing. Paired t-tests confirmed highly significant differences (p < 0.001) with large effect sizes. Finer droplets also reduced run-off and evaporation losses by over 60%. These findings demonstrate that nozzle optimization markedly enhances resource efficiency and environmental protection in precision rice spraying. Full article

The system made by a charged particle interacting with a single electrostatic wave which propagates perpendicularly to the magnetic field, at a frequency larger than the cyclotron one, has been extensively studied in the literature due to its implications for ion heating in magnetized plasmas. It is known that a threshold in the electrostatic potential must be exceeded in order for stochastic particle motion and heating to occur. Regardless of its amplitude, however, the electrostatic wave induces a periodic oscillation in the particle motion. We show, by analytical and numerical arguments, that this dynamic is non-adiabatic, meaning that the particle does not land back in its initial state when the wave is slowly turned off. This way, particle energization (although not rigorous heating) occurs even under sub-threshold conditions. Full article

This review explores the pervasive role of water in generating, storing, and mediating electric charge across natural and artificial systems. Far from being a passive medium, water actively participates in electrostatic and electrochemical processes through its intrinsic ionization, interfacial polarization, and charge separation mechanisms. The Maxwell–Wagner–Sillars (MWS) effect is presented as a unifying framework explaining charge accumulation at air–water, water–ice, and water–solid interfaces, forming dynamic “electric mosaics” across Earth’s environments. The authors integrate diverse phenomena—triboelectricity, hygroelectricity, hydrovoltaic effects, elastoelectricity, and electric-field-driven phase transitions—showing that ambient water continually shapes the planet’s electrical landscape. Electrostatic shielding by humid air and hydrated materials is described, as well as the spontaneous electrification of sliding or dripping water droplets, revealing new pathways for clean energy generation. In addition, the review highlights how electric fields and interfacial charges alter condensation, freezing, and chemical reactivity, underpinning discoveries such as microdroplet chemistry, “on-water” reactions, and spontaneous redox processes producing hydrogen and hydrogen peroxide. Altogether, the paper frames water as a universal electrochemical medium whose interfacial electric imprint influences atmospheric, geological, and biological phenomena while offering novel routes for sustainable technologies based on ambient charge dynamics and water-mediated electrification. Full article

The interaction of an ultra-short, high-power laser pulse with a solid target, in the so-called Target Normal Sheath Acceleration (TNSA) configuration, produces particles in the MeV range. Fast electrons can escape from the target after the interaction, inducing electrostatic fields on the order of TV/m close to the target surface. These fields accelerate MeV protons and heavy ions at the rear of the target, allowing them to escape. The complete process is difficult to probe, as it occurs on the sub-ps timescale. At the INFN-LNF SPARC_LAB test facility, single-shot diagnostics such as the Electro-Optic Sampling (EOS) are being developed and tested for time-resolved direct measurements of the produced electrons and associated longitudinal electric fields. Electrons are the core of the process, and their properties determine the following production of positive charge particles and electromagnetic radiation. Different target geometries and materials are being investigated to analyze the enhancement of fast electron emission and the correlation with positive charge production. Simultaneous observations of electron and proton beams have been performed using two diagnostic lines, the EOS for electrons and a time-of-flight (TOF) detector for protons. This work provides an overview of the previous experiments performed at SPARC_LAB dedicated to the TNSA characterization. Full article

In this paper, we present a new mixed weak Galerkin FEM for Maxwell’s equations in the primary electrostatic field–Lagrange multiplier. Our numerical scheme is equipped with stable finite elements composed of polynomials of degree ℓ for the electrostatic variable and polynomials of degree $𝓁+1$ for the Lagrange multiplier variable; the electrostatic field and the Lagrange multiplier variables are discontinuous. We demonstrate some error estimations that are optimal as a function of the mesh size and we study some numerical tests in a 2D domain. The numerical results perfectly confirm those shown theoretically. Full article

As global food demand rises and agricultural labor shortages intensify, robotic automation has become essential for sustainable fruit grasping. Among emerging technologies, ElectroAdhesion (EA) grippers offer a promising alternative to traditional mechanical end-effectors, enabling gentle, low-pressure handling through electrostatically induced adhesion. This paper presents a methodical review of EA grippers applied to fruit grasping, focusing on their advantages, limitations, and key design considerations. A targeted literature search identified ten EA-based and hybrid EA gripping systems tested on fruit manipulation, though none has yet been tested in real-world environments such as fields or greenhouses. Despite a significant variability in experimental setups, materials, and grasp types, qualitative insights are drawn from our analysis demonstrating the potentialities of EA technologies. The EA grippers found in the targeted review are effective on diverse fruits, shapes, and surface textures; they can hold load capacities ranging from 10 g (~0.1 N) to 600 g (~6 N) and provide minimal compressive stress at high electrostatic shear forces. Along with custom EA grippers designed accordingly to specific use cases, field and greenhouse testing will be crucial for advancing the technology readiness level of EA grippers and unlocking their full potential in automated crop harvesting. Full article

Hydraulically Amplified Self-Healing Electrostatic (HASEL) actuators promise a future of adaptive robotics in a world where robotics is becoming increasingly integrated into our daily lives. Adaptive robotics needs to control multiple outputs with precision and speed. Unfortunately, expensive High Voltage control restricts the development of the HASEL actuator for commercial applications. This paper demonstrates a low-cost multi-channel High Voltage Power Supply (HVPS). The HVPS takes a 6 V input and controls multiple HASEL actuators from 0 to 10 kV, with a slew rate of up to 117.7 kV/s. In addition to controlling multiple channels, the low-cost HVPS can control two outputs with a single control module in an alternating pattern, similar to the way muscles control movement in alternating sequences—e.g., biceps and triceps. Previous work has shown that this low-cost HVPS is 95% cheaper than other power supplies used in the field of HASEL actuators. This work builds on the work reducing the cost of the HVPS by an additional 40%. This low-cost HVPS also reduces the amount of input required for control from four PWMs to one PWM with enable pins, drastically improving the performance of the device for multi-channel operation. Full article

Antihypertensive drugs exhibit high resistance and low biodegradability, which leads to their insufficient removal in conventional treatment processes. This study focuses on the removal of selected pharmaceuticals from wastewater using physical–biological methods. These methods included pretreatment by an electrostatic field and biodegradation by a mixed culture of Rhodococcus bacteria. Full article

Microplastics (MPs) and nanoplastics (NPs) are emerging aquatic contaminants that pose environmental and public health risks due to their persistence, ubiquity, and ability to adsorb co-contaminants. This scoping review synthesises findings from 57 experimental studies and five review studies published between 2019 and 2025 on the use of biochar-based materials for the removal of microplastics from water and wastewater. Guided by the hypothesis that surface-modified biochars, such as magnetised, surfactant-coated, or chemically activated forms, achieve high removal efficiencies through multimodal mechanisms (e.g., electrostatic attraction, hydrophobic interactions, π–π stacking, and physical entrapment), this review applies PRISMA-based protocols to systematically evaluate biochar feedstocks, pyrolysis conditions, surface modifications, polymer types, removal mechanisms, and regeneration approaches. Scopus, Web of Science, and PubMed were searched until 30 May 2025 (English-only), and 62 studies were included. The review was not registered, and no protocol was prepared. The results confirm a high removal efficiency (>90%) in most experimental studies, particularly under controlled laboratory conditions and using pristine polystyrene. However, the performance declines significantly in complex matrices (e.g., wastewater and surface water) owing to dissolved organic matter, ionic competition, and particle heterogeneity, thus supporting the guiding hypothesis. This review also identifies critical methodological gaps, including narrow plastic typologies, a lack of standardised testing protocols, and limited field-scale validation. Addressing these gaps through environmentally realistic testing, regeneration optimisation, and harmonised methods is essential for transitioning biochar from a promising sorbent to a practical water treatment solution. Full article