Explore the vast range of titles available.

BackgroundThe Swiss Bus-Exposure-Matrix (BEM) is a database detailing exposure levels for 17 physical, chemical, and ergonomic hazards across 705 bus models used in Switzerland from 1980 to the present. This study uses BEM data to describe and assess temporal variations in exposure to electromagnetic fields (EMF) and to estimate individual cumulative exposure among Swiss bus drivers.Material and MethodsElectromagnetic fields were measured using the dosimeter PMM 8053, focusing on low-frequency (5 to 100 kHz) and high-frequency (100 kHz to 7 GHz) electric and magnetic fields. Exposure values were averaged using the robust regression on order statistics (ROS) method and modeled using Integrated Nested Laplace Approximation, then applied to the Swiss bus inventory to construct the BEM. Data from a 2022 online questionnaire, which listed the buses driven by participants, were used to assign EMF exposure values by cross-referencing bus models.ResultsThe study included 916 drivers, of whom 710 (77.5%) indicated their bus-driving history, the oldest having started in 1985. The BEM assessed annual EMF exposure based on work rates. In 2022, mean exposures were 0.40 V/m for high-frequency electric fields, 0.49 V/m for low frequency electric fields, and 0.18 µT for low-frequency magnetic fields. From 1985 to 2022, mean exposures to high-frequency and low-frequency electric fields increased, while low-frequency magnetic field exposure decreased. The highest cumulative high-frequency electric field exposure was 19.7 V/m for a full-time bus driver with 34 years of employment, and the lowest was 0.12 V/m for a part-time bus driver with one year of employment.ConclusionsWhile personal exposure measurements are the gold standard in occupational hygiene and epidemiology, they are challenging to collect for a large cohort. The Swiss BEM provides an acceptable alternative for assessing EMF exposure in bus drivers, facilitating the investigation of their potential short- and long-term health effects.FundingFederal Office of Environment (FOEN) (BAFU-320.1-01-60677/2/1/10), Federal Office of Transport (FOT)

The largest electric fields between 18 and 30 solar radii are in narrowband waves simultaneously observed at a few Hz (somewhat above the local proton gyrofrequency) and a few hundred Hz (far below the lower hybrid frequency), with the higher-frequency wave triggered at specific phases of the lower-frequency wave. This wave pair, called “triggered ion-acoustic waves” (TIAWs), has been shown to both be physical and to occur at times of electron heating. A theory of electron heating and acceleration by the low-frequency wave has been presented. While this theory and the TIAW results strongly suggest the presence of low-frequency electric fields that are parallel to the local magnetic field, such fields have not been directly observed. In this paper, such parallel electric field observations are reported, and TIAWs are further described to conclude that they occur during about 75% of the Parker Solar Probe passes through 18–30 solar radii, and when present, they are the dominant wave signal, lasting for hours. In the presence of these parallel electric fields, electrons are heated while, in their absence, there is no electron heating. That there is no heating between 18 and 30 solar radii in the absence of TIAWs is a most significant result because it invalidates other proposed mechanisms that predict heating in this radial range all of the time.

Static, quasi-static and low frequency electric fields are being used in many fields of science and engineering. They are utilized in research studies of fundamental properties of materials, exploration of high-energy physics, in biology and medicine, etc., but also in a multitude of practical applications such as precipitation, painting, xerography, to name a few. In all these endeavors it is a good practice to find out what the electric fields are in terms of value, direction, and temporal and spatial distribution. This information can be crucial for making the application successful. Electric fields are also being created by many naturally occurring and man-made phenomena. The aim of this paper is to present different options for electric field evaluation and measurement. Aside from traditional approaches, new concepts using machine learning in electric field assessment and interpretation are discussed. As technologies progress, electric field detection methods become a part of sensor fusion realm by providing additional capabilities in process, environmental and situational awareness monitoring. They can provide unique information enhancing our knowledge and understanding. Examples of such sensor integrations are shown and explained.

The operating principles of a DC and low frequency electric field detector are developed, after which, examples of earlier important electric field measurements are presented, including, the first observation of parallel electric fields in the auroral acceleration region, the first observation of time domain structures in space, the first experimental verification of symmetric magnetic field reconnection, the first observations of triggered ion acoustic waves, and oblique whistlers that directly accelerate electrons. Future possible improvements in the electric field measurement technique are described.

Collisionless low-Mach-number shocks are abundant in astrophysical and space plasma environments, exhibiting complex wave activity and wave–particle interactions. In this paper, we present 2D Particle-in-Cell (PIC) simulations of quasi-perpendicular nonrelativistic (v sh ≈ (5500–22000) km s−1) low-Mach-number shocks, with a specific focus on studying electrostatic waves in the shock ramp and precursor regions. In these shocks, an ion-scale oblique whistler wave creates a configuration with two hot counterstreaming electron beams, which drive unstable electron acoustic waves (EAWs) that can turn into electrostatic solitary waves (ESWs) at the late stage of their evolution. By conducting simulations with periodic boundaries, we show that the EAW properties agree with linear dispersion analysis. The characteristics of ESWs in shock simulations, including their wavelength and amplitude, depend on the shock velocity. When extrapolated to shocks with realistic velocities (v sh ≈ 300 km s−1), the ESW wavelength is reduced to one-tenth of the electron skin depth and the ESW amplitude is anticipated to surpass that of the quasi-static electric field by more than a factor of 100. These theoretical predictions may explain a discrepancy, between PIC and satellite measurements, in the relative amplitude of high- and low-frequency electric field fluctuations.

Spinal cord injury (SCI) can cause permanent loss of sensory, motor, and autonomic functions, with limited therapeutic options available. Low-frequency electric fields with changing polarity have shown promise in promoting axon regeneration and improving outcomes. However, the metal electrodes used previously were prone to corrosion, and their epidural placement limited the penetration of the electric field into the spinal cord. Here, we demonstrate that a thin-film implant with supercapacitive electrodes placed under the dura mater can safely and effectively deliver electric field treatment in rats with thoracic SCI. Subdural stimulation enhanced hind limb function and touch sensitivity compared to controls, without inducing a neuroinflammatory response in the spinal cord. While axon density around the lesion site remained unchanged after 12 weeks, in vivo monitoring and electrochemical testing of electrodes indicated that treatment was administered throughout the study. These results highlight the promise of electric field treatment as a viable therapeutic strategy for achieving long-term functional recovery in SCI. Spinal cord injury leads to lasting motor and sensory loss, with limited treatment options. Here, the authors show that subdural electric field stimulation delivered across the injury via an ultra-thin implant improves functional recovery in rats.

Low frequency electric fields were exposed to various water samples using platinum electrodes mounted near the water surface. Responses were monitored using a spectro-radiometer and a contact-angle goniometer. Treatment of DI (deionized), EZ (Exclusion Zone), and bulk water with certain electromagnetic frequencies resulted in a drop of radiance persisting for at least half an hour. Compared to DI water, however, samples of EZ and bulk water showed lesser radiance drop. Contact-angle goniometric results confirmed that when treated with alternating electric fields (E = 600 ± 150 V/m, f = 7.8 and 1000 Hz), droplets of EZ and bulk water acquired different charges. The applied electric field interacted with EZ water only when electrodes were installed above the chamber, but not beneath. Further, when DI water interacted with an electric field applied from above (E = 600 ± 150 V/m, f = 75 Hz), its radiance profile became similar to that of EZ water. Putting these last two findings together, one can say that application of an electric field on DI water from above (E = 600 ± 150 V/m, f = 7.8 to 75 Hz) may induce a molecular ordering in DI water similar to that of EZ water.

A Morris–Lecar neuron model is considered with electric and magnetic field effects where the electric field is a time-varying sinusoid and magnetic field is simulated using an exponential flux memristor. We have shown that the exposure to electric and magnetic fields have significant effects on the neurons and has exhibited complex oscillations. The neurons exhibit a frequency-locked state for the periodic electric field and different ratios of frequency-locked states with respect to the electric field frequency is also presented. To show the impact of the electric and magnetic fields on network of neurons, we have constructed different types of network and have shown the network wave propagation phenomenon. Interestingly, the nodes exposed to both electric and magnetic fields exhibit more stable spiral waves compared to the nodes exhibited only to the magnetic fields. Also, when the number of layers is increased, the range of electric field frequency for which the layers exhibit spiral waves also increases.

The article investigates a multi-element disk sensor of the components of the low-frequency electric field intensity vector, manufactured using new technologies. The sensor is suitable for measuring the intensity of electric fields adversely affecting a person. In this regard, the problem solved in the article is relevant. The results of the study made it possible to create such a sensor, evaluate its metrological characteristics and establish their dependence on the degree of homogeneity of the electric field. The established relationship between the sensor error and the degree of heterogeneity of the electric field makes it possible to determine the spatial range of measurement from a given error or to establish the sensor error from a given spatial range of measurement. For example, a sensor error of 3% corresponds to the spatial measurement range a, determined by the distance to the field source from 0 R to 5·R (a ≤ 0.2), where R is the radius of the disk of the base of the sensor.

Low-frequency electric field sensors are essential for applications in geophysics, electrical engineering, aerospace, and medical technology. However, conventional technologies often suffer from intrinsic trade-offs among traceability, multidimensional vector detection, and miniaturization, which significantly hinder their scalability and deployment in compact platforms. To address these challenges, we propose a vector-resolved quasi-static electric field sensor based on a Rydberg dipolar chain, where the external field reorients the atomic quantization axis and thereby modulates the angle-dependent dipolar exchange interaction. Using a unified framework combining time-domain propagation, Ramsey-mode spectroscopy, and end-to-end Green’s-function analysis, we identify three complementary observables—arrival time, eigenmode frequency shifts, and transmission fringes—that encode both the amplitude and direction of the applied field. The approach operates at micrometer scales compatible with optical-tweezer arrays, offers tunable sensitivity near the magic angle, and provides multi-channel readout within a single platform. Our results establish a compact and experimentally feasible route toward high-resolution, vector-sensitive low-frequency electrometry with the potential for quantum-enhanced performance.