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This research aims to validate an electrostatics characterization device to better understand the process of static charge generation in textile materials and to see how different factors affect it. This electrostatic device offers a variety of settings for controlling sample electrostatic activation and has a sample size range of up to one square meter. It can move in both horizontal and vertical directions in a controlled manner, providing a variety of possibilities for testing the effect of various movement features on electrostatic charge formation. Not only the textile polymer but also the motion characterizations influence the generation of electrostatic charges in textiles. The influence of frequency, pressure, dwell time between moves, test duration, effect of different sample sizes, and amplitude of movement on electrostatic charge generation was studied in greater detail. Two different parameters of the electrostatic waveform (peak voltage and peak-to-peak voltage) were investigated. The generation of electrostatic charges is proportional to the peak voltage and peak-to-peak voltage of the electrostatic waveform. Overall electrostatic charge generation increases with increasing frequency, stepping height, applied pressure at the same frequency, and sample size, but decreases with increasing dwell time between moves at the same frequency. The charge also increases with test duration until a saturation point is reached.

Understanding the multitude of factors that control pulmonary deposition is important in assessing the therapeutic or toxic effects of inhaled particles. The use of increasingly sophisticated in silico models has improved our overall understanding, but model realism remains elusive. In this work, we use Large Eddy Simulations (LES) to investigate the deposition of inhaled aerosol particles with diameters of dp=0.1,0.5,1,2.5,5 and 10μm (particle density of 1200kg/m3). We use a reconstructed geometry of the human airways obtained via computed tomography and assess the effects of inlet flow conditions, particle size, electrostatic charge, and flowrate. While most computer simulations assume a uniform velocity at the mouth inlet, we found that using a more realistic inlet profile based on Laser Doppler Anemometry measurements resulted in enhanced deposition, mostly on the tongue. Nevertheless, flow field differences due to the inlet conditions are largely smoothed out just a short distance downstream of the mouth inlet as a result of the complex geometry. Increasing the inhalation flowrate from sedentary to activity conditions left the mean flowfield structures largely unaffected. Nevertheless, at the higher flowrates turbulent intensities persisted further downstream in the main bronchi. For dp>2.5μm, the overall Deposition Fractions (DF) increased with flowrate due to greater inertial impaction in the oropharynx. Below dp=1.0μm, the DF was largely independent of particle size; it also increased with flowrate, but remained significantly lower. Electrostatic charge increased the overall DF of smaller particles by as much as sevenfold, with most of the increase located in the mouth–throat. Moreover, significant enhancement in deposition was found in the left and right lung sub-regions of our reconstructed geometry. Although there was a relatively small impact of inhalation flowrate on the deposition of charged particles for sizes dp<2.5μm, impaction prevailed over electrostatic deposition for larger particles as the flowrate was increased. Overall, we report a significant interplay between particle size, electrostatic charge, and flowrate. Our results suggest that in silico models should be customized for specific applications, ensuring all relevant physical effects are accounted for in a self-consistent fashion.

The evolutionary interplay between predator and prey has significantly shaped the development of snake venom, a critical adaptation for subduing prey. This arms race has spurred the diversification of the components of venom and the corresponding emergence of resistance mechanisms in the prey and predators of venomous snakes. Our study investigates the molecular basis of venom resistance in pythons, focusing on electrostatic charge repulsion as a defense against α-neurotoxins binding to the alpha-1 subunit of the postsynaptic nicotinic acetylcholine receptor. Through phylogenetic and bioactivity analyses of orthosteric site sequences from various python species, we explore the prevalence and evolution of amino acid substitutions that confer resistance by electrostatic repulsion, which initially evolved in response to predatory pressure by Naja (cobra) species (which occurs across Africa and Asia). The small African species Python regius retains the two resistance-conferring lysines (positions 189 and 191) of the ancestral Python genus, conferring resistance to sympatric Naja venoms. This differed from the giant African species Python sebae, which has secondarily lost one of these lysines, potentially due to its rapid growth out of the prey size range of sympatric Naja species. In contrast, the two Asian species Python brongersmai (small) and Python bivittatus (giant) share an identical orthosteric site, which exhibits the highest degree of resistance, attributed to three lysine residues in the orthosteric sites. One of these lysines (at orthosteric position 195) evolved in the last common ancestor of these two species, which may reflect an adaptive response to increased predation pressures from the sympatric α-neurotoxic snake-eating genus Ophiophagus (King Cobras) in Asia. All these terrestrial Python species, however, were less neurotoxin-susceptible than pythons in other genera which have evolved under different predatory pressure as: the Asian species Malayopython reticulatus which is arboreal as neonates and juveniles before rapidly reaching sizes as terrestrial adults too large for sympatric Ophiophagus species to consider as prey; and the terrestrial Australian species Aspidites melanocephalus which occupies a niche, devoid of selection pressure from α-neurotoxic predatory snakes. Our findings underline the importance of positive selection in the evolution of venom resistance and suggest a complex evolutionary history involving both conserved traits and secondary evolution. This study enhances our understanding of the molecular adaptations that enable pythons to survive in environments laden with venomous threats and offers insights into the ongoing co-evolution between venomous snakes and their prey.

This paper presents an analysis of recorded variations (anomalies) in the potential gradient of electrical field in the atmosphere caused by the propagation of eruption plumes discharged by eruptions of Shiveluch and Bezymianny volcanoes in Kamchatka. The anomalies were recorded at various distances from eruption centers and under different conditions of atmospheric stratification. These conditions have enabled us to show that the eruption plumes of Shiveluch and Bezymianny possessed a 3D electrostatic structure that is consistent with a known phenomenological model derived on the basis of surveys conducted on various volcanoes worldwide. According to this model, the top of an eruption plume contains a positive volumetric electrostatic charge, while the respective charges are negative in the middle, and positive in the lower part of the plume.

Floor covering samples of different thickness, pile height, pile design, materials, construction methods, and applied finishes were selected for electrostatic characterization with a standard plotter platform and a newly designed digital platform. There is an existing standard ISO 6356 in which the voltage generated by a human walking on the carpet is measured with human involvement under controlled conditions. A walking person performs the original test procedure to generate the electrostatic charge and manually calculates results. In contrast, the newly designed system does not require a person to calculate peaks and valleys for the generated electrostatic charges, which offers advantages in terms of accuracy, consistency, and reproducibility, and eliminates human error. The electronic platform is extended with an automated foot for a fully automated test, called “automatic mode”, that has a fixed capacitive and resistive circuit, in replace of human body resistance, and capacitance that varies from person to person and over time. The procedure includes both the old and new platforms, where the new platform is placed in a “human walking” mode to compare the two and validate the new device. Next, all the floor coverings are tested in automatic mode with the automated foot to compare and validate results. We conclude that the new testing device can fully characterize the electrostatic behavior of textile without the involvement of a human, which offers advantages in terms of accuracy, consistency, and reproducibility.

Electrostatic adsorption is an important complement to the mechanical filtration for high-efficiency air filtering. However, the electrostatic charge decays with time, especially in humid conditions. In this work, a self-charging air filter is presented to capture airborne particles in an efficient and long-lasting manner without the need of external power sources. Leveraging the triboelectric effect between the electrospun poly(vinylidene fluoride) nanofiber film and nylon fabric, the self-charging air filter-based mask excited by breathing can continuously replenish electrostatic charges. As a result, its effective lifespan is up to 60 hours (including 30 hours of wearing), with a minimum filtration efficiency of 95.8% for 0.3-μm particles. The filtration efficiency and lifespan are significantly higher than those of a commercial surgical mask. Furthermore, we uncover the quantitative relation between filtration efficiency and surface electrostatic potential. This work provides an effective strategy to significantly prolong the electrostatic adsorption efficacy for high-performance air-filtering masks. The decay of electrostatic charges largely reduces the protective efficacy of electret masks. Here, the authors report a triboelectrification-based self-charging electrostatic face mask with high airborne particle capture efficiency and prolonged stability.

The charge transfer phenomenon of contact electrification even exists in the liquid–solid interface by a tiny droplet on the solid surface. In this work, we have investigated the contact electrification mechanism at the liquid–solid interface from the electronic structures at the atomic level. The electronic structures display stronger modulations by the outmost shell charge transfer via surface electrostatic charge perturbation than the inter-bonding-orbital charge transfer at the liquid–solid interface, supporting more factors being involved in charge transfer via contact electrification. Meanwhile, we introduce the electrochemical cell model to quantify the charge transfer based on the pinning factor to linearly correlate the charge transfer and the electronic structures. The pinning factor exhibits a more direct visualization of the charge transfer at the liquid–solid interface. This work supplies critical guidance for describing, quantifying, and modulating the contact electrification induced charge transfer systems in triboelectric nanogenerators in future works. Understanding contact electrification within the liquid–solid interface is critical for further applications in energy conversion and storage devices. Here, the authors reveal liquid–solid interactions regarding the charge transfer mechanism and pinning factor from the electronic perspective.

The spontaneous electrification of surfaces and interfaces is a widespread phenomenon that produces unexpected effects in chemical reactivity and mass charge transfer, revealed in abundant literature over the past twenty years. The pervasive presence of electrostatic charges originates from many sources, including friction, mechanochemical reactions, phase change, flexoelectricity, and others. Since fused deposition modeling undergoes most well-known electrification mechanisms, it would be not surprising that 3D-printed objects display large amounts of charge. Here we uncover the hitherto unexplored realm of electrostatic charging in 3D printing, underscores the impact of printing parameters on charge generation in polymers. Substrates, printing speed, temperature, and printing direction each exert distinct impacts on charge buildup, depending upon the material used for printing. We also develop simple protocols employing common multimeters for charge monitoring, while substrates subjected to corona charging or triboelectrification demonstrate effective methods for charge control or mitigation. An original development is achieved by demonstrating the ability to print quasi-electrets, indicating a potential revolution in electret technology. The implications of these findings establish the groundwork for advancements in 3D printing technology and electrostatics, creating new scientific opportunities for a better understanding of matter. In this work, authors investigate how printing parameters like speed, temperature, and direction affect electrostatic charge in 3Dprinted polymers. They develop protocols for charge monitoring and control, demonstrating the potential to print quasi-electrets and offering insights into electrostatics during 3D printing.

Eye tracking provides valuable insight for analyzing visual attention and underlying thinking progress through the observation of eye movements. Here, a transparent, flexible and ultra-persistent electrostatic sensing interface is proposed for realizing active eye tracking (AET) system based on the electrostatic induction effect. Through a triple-layer structure combined with a dielectric bilayer and a rough-surface Ag nanowire (Ag NW) electrode layer, the inherent capacitance and interfacial trapping density of the electrostatic interface has been strongly enhanced, contributing to an unprecedented charge storage capability. The electrostatic charge density of the interface reached 1671.10 μC·m −2 with a charge-keeping rate of 96.91% after 1000 non-contact operation cycles, which can finally realize oculogyric detection with an angular resolution of 5°. Thus, the AET system enables real-time decoding eye movements for customer preference recording and eye-controlled human-computer interaction, supporting its limitless potentiality in commercial purpose, virtual reality, human computer interactions and medical monitoring. Eye tracking systems are crucial for eye health-monitoring and human-machine engineering. Here, Shi et. al. report a transparent and flexible active eye tracking system based on an electrostatic induction effect, enabling visual preference analysis and eye-controlled human-computer interaction.

Excessive use of nitrogen fertilizer and inappropriate fertilization designs have negative results in agricultural ecosystems, such as considerable nitrogen losses through nitrogen dioxide (NO2) soil leaching and ammonia NH3 volatilization. In addition, climate change, with rising summer temperatures and reduced precipitation, leads to production declines and water shortages in the soil. This review aims to highlight the characteristics of natural zeolite and focus on their multiple uses in agriculture. These minerals are tectosilicates showing an open three-dimensional structure involving the cations required to balance the framework electrostatic charge of aluminum and silicon tetrahedral units. Different research groups reported more than fifty natural zeolites; chabazite, clinoptilolite, phillipsite, erionite, stilbite, heulandite, and mordenite are the most well-known. Zeolites are great tools to help the farmer and agronomist cope with several issues, such as soil or water pollution, contamination by heavy metals, loss of nutrients, and loss of water-use efficiency (WUE) of drylands. These natural crystalline aluminosilicates are considered soil conditioners to improve soil chemical and physical properties, such as saturated hydraulic conductivity (Ks), infiltration rate, cation exchange capacity (CEC), and water-holding capacity (WHC). Owing to their properties, these materials are able to reduce nitrate leaching and ammonia volatilization. Zeolites are also known for their carrying capacity of slow-release macronutrients, micronutrients, and fertilizers. However, the potential of these materials in agricultural areas is apparent, and zeolites show the promise of contributing directly to improve agricultural ecosystems as a sustainable product.