Electrical Pulses Research Articles

Stimulation conditions leading to electrical vestibular co-stimulation in cochlear implant users.

The study objective was to investigate the influence of electrical stimulus properties on cervical and ocular vestibular-evoked myogenic potentials to electrical stimulation by cochlear implants (e-cVEMPs, e-oVEMPs). E-VEMPs were recorded in adult Nucleus cochlear implant (CI) patients using electric pulse trains (4 biphasic pulses at 1000 Hz burst rate). Ground path and stimulation electrodes were varied between monopolar stimulation at basal electrode contact E3 (MP1 + 2 E3), monopolar stimulation at apical electrode contact E20 (MP1 + 2 E20), and bipolar transmodiolar stimulation between E3 and E14 (BP E3-E14). The electric pulse train was further varied to 2 pulses at 1000 Hz, 2 pulses at 500 Hz, and a single pulse, in patients with present e-VEMP responses. VEMPs to bone-conducted vibration (BCV) were recorded as reference in all participants. Measurements were conducted in 30 ears of 27 participants (mean age 49.3 years, SD 12.7 years). E-VEMPs were present in 13 ears (43%). 5 of the 13 cases showed e-VEMPs but no BCV evoked VEMPs. Response numbers increased with increasing stimulation levels. The highest response rate of 40% was obtained for MP1 + 2 E3 stimulation. Stimulus variation did not affect response numbers. E-VEMP amplitudes were comparable to BCV-stimulated VEMPs. Latencies were up to 3.1 ms shorter for electric stimulation. Some patients showed e-VEMP thresholds close to or below the electric hearing threshold level. The occurrence of e-VEMPs is dependent on current path and stimulation level. Vestibular co-stimulation by the CI is more likely in patients with high stimulation levels and for monopolar stimulation of basal electrode contacts. 4.

Prospects of pulsed electric fields technology in food preservation and processing applications from sensory and consumer perspectives

SummaryPulsed electric field (PEF) technology is emerging as a versatile and effective alternative to traditional thermal processing, adeptly meeting consumer demands for fresh, safe, tasty, nutritious, and sustainable food products. By applying high‐voltage electric pulses for microseconds to milliseconds, PEF achieves microbial inactivation with minimal thermal impact. Beyond preservation, PEF technology can be used as a pre‐treatment for raw food materials to modify their cell structure, thus facilitating the subsequent food processing steps. Although initially applied to liquid foods, PEF application has been expanded to a diverse range of food categories, including juices, wines, potatoes, meats, and freeze‐dried products. Each application of PEF involves specific process parameters, which significantly influence the product outcomes. This review discusses the application of PEF across various food categories, with a focus on its impact on sensory attributes under different settings. The discussion will mainly revolve current research gaps and proposes strategies to increase consumer acceptance of PEF‐treated products, along with approaches for effectively communicating the benefits of this novel processing technology. It was found that emphasising the sensory, nutritional, and shelf‐life benefits on product packaging, and highlighting its environmental‐friendly benefit can improve consumer acceptance of PEF‐treated products. Furthermore, educating industry practitioners about the advantages of PEF is crucial for its broader implementation in food manufacturing. The successful advancement of PEF technology hinges on collaboration efforts among technologists, industry experts, sensory, and consumer scientists.

Repair Engineering of Crystal Structure in van der Waals Materials by Probe Electron Beam.

The advancement of electronic technology has led to increasing research on performance and stability. Continuous electrical pulse stimulation can cause crystal structure changes, affecting performance and accelerating aging. Controlled repair of these defects is crucial. In this study, we investigated crystal structure changes in van der Waals (vdW) InSe crystals under continuous electric pulses by using electron beam lithography (EBL) and spherical aberration corrected transmission electron microscopy (Cs-TEM). Results show that electrical pulses induce amorphous regions in the InSe lattice, increasing the device resistance. We used Cs-STEM probe scanning for precise repair, abbreviated SPRT, to optimize device performance. SPRT is related to electric fields induced by the electron beam and can be applied to other 2D materials like α-In2Se3 and CrSe2, offering a potential approach to extend device lifespan.

Pulsed-field ablation-is it the only energy source for ablation in the future? : Pro/Contra

Pulsed field ablation (PFA) is anonthermal energy source used for cardiac ablation procedures. Cell death during PFA occurs via electroporation: ultrarapid (micro- to nanosecond) electrical pulses are applied to destabilize cell membranes causing irreversible pores. PFA leads to preferential ablation of myocardiocytes, sparing adjacent tissue like the esophagus or phrenic nerve. Preliminary clinical studies show high efficacy and agood safety profile in atrial fibrillation patients undergoing pulmonary vein isolation. The question remains, however, whether this new technology will replace well-known and established thermal energy sources like radiofrequency current or cryoablation within the next 5years.

ELECTRIC PULSE METHOD OF ROCK DESTRUCTION AND BLAST WELLS DRILLING

The paper proposes an electric pulse method for rock destruction and drilling blast holes based on microwave radiation generated by a magneto-cumulative generator. A description of an electric pulse method installation with a magneto-cumulative generator, protected by a Russian patent, is provided. Relationships are given for an engineering calculation method during the periods of mastering a new technology and it is shown that the introduction of an innovative technology based on the proposed electric pulse method will allow us to talk about a low dependence of the efficiency of electric pulse drilling on the strength of rocks.

THE EFFECT OF ELECTRIC PULSE TREATMENT ON THE PROPERTIES OF HEMP FIBRE

The production of competitive textile products can be ensured by using natural, environmentally friendly fibres, which include hemp fibre, as raw materials. To expand the possibility of its use, an essential operation is the pre-treatment of the fibre. The use of electric pulse processing of hemp fibre will provide the ability to control the depth of cottonization, select optimal parameters that collectively evaluate the spinning ability of the fibre and correspond to the permissible similar indicators of cotton fibre. The purpose of the work done is to study the mechanism of electric pulse processing of hemp fibre by identifying its structural characteristics under various processing modes for further use. The work carried out studies of the process of cottonization of hemp fibre by a physical-mechanical method using an electric pulse discharge from 500 to 2500 cycles. An effective mode of electric pulse processing of fibres has been established, amounting to 2500 pulses of electric discharges, which makes it possible to obtain cottonized hemp fibre with the required spinning ability. The parameters of cottonized hemp fibre have been determined, allowing the use of hemp cottonin to produce mixed yarn using a card spinning system on cotton spinning equipment.

Evolution characteristics of an induced electric charge signal and identification method of charge for instability failure in loaded coal

A coal-loaded charge induction monitoring system is developed to effectively forecast the dynamic disasters caused by coal failure. Specifically, a digital finite impulse response (FIR) filter is designed to denoise and filter the signal, and the time-frequency domain evolution of induced charge signals is analyzed during coal failure experiments. The quantitative relationships between the induced electric charge and stress-strain energy, and ultimately, between induced electric charge and coal deformation/failure, are revealed. Ultimately, the electric charge sensor exhibits high signal collection frequency and high sensitivity, and the FIR low-pass filter constructed in MATLAB effectively denoises and filters induced charge signals. The main frequency range of the white noise is 50–500 Hz, and the main frequency of the charge signal induced by coal deformation and failure is concentrated in the range of 0–50 Hz. The optimal distances for monitoring cubic and cylindrical raw coal samples using this sensor are 9 mm and 11 mm, respectively. Notably, strain energy is released faster when it can dissipate more readily, and induced charge pulses become denser when more intense signals produce large fluctuations. A method is proposed to identify coal deformation and failure based on changes in the induced electric charge. This study provides a new means of monitoring the early warning signs of dynamic coal mine disasters. Based on our experimental results and conclusions, a new method is proposed to identify coal deformation and failure based on changes in the induced electric charge. The precursor to the moment of coal failure can be identified by monitoring the amplitude of the induced charge, the dynamic trend of fluctuation, and the cumulative number of induced electric charge pulses during the process of coal deformation.

Analysis of EFT Transmission Characteristics in Armoured Shielded Cables

Abstract Electrical fast transient pulses (EFT) generated when a gas-isolated substation (GIS) is switched on and off. The EFT is transmitted to the control chamber through the secondary control cable, which will cause the failure of the control equipment. In this paper, the three-dimensional electromagnetic simulation software CST (Computer Simulation Technology) is used to study the transmission characteristics of EFT in armored shielded control cables. First, an EFT analog signal is generated using an interference generator. Analyze the difference between the EFT analog signal and the EFT model in the IEC standard. The conversion method of FFT is used to analyze the spectral characteristics of EFT analog signals. According to the structural parameters, a 20-meter-long model of an armored shielded control cable was built in the CST cable studio The effect of the grounding of the shield and armor layers on the attenuation and crosstalk of EFT signals in the cable is studied. Finally, the EFT experiment of 1m long armored shielded cable is carried out, and the reliability of the research method is verified by comparing with the simulation results.

A Study of the Thermodynamic Properties of Thermosetting Synthetic Resins after Electric Pulse Treatment

A Study of the Thermodynamic Properties of Thermosetting Synthetic Resins after Electric Pulse Treatment

Research of electrode materials for the creation of multifunctional current sources with increased capacity as a components of the energy sector of an efficient urban environment

As part of creating a comfortable and safe environment, constructing energy-efficient residential and industrial buildings and structures that meet modern requirements and standards, the development of the production of environmentally friendly renewable and new individual energy sources is becoming especially relevant. In this regard, there is a need to increase the energy capacity of electrochemical cells. Research has been carried out on the metallized conductive materials creation based on rolled carbon non-woven material “Busofit” with the sequential application of metal coatings of titanium and silver using ion-plasma sputtering and electric pulse dispersion methods. It has been shown that surface layer metallization of the electrode material with titanium can improve the electrochemical cell characteristics. Additional silver film deposition leads to further cell performance improvement. It has been confirmed that the multilayer structure interfacial resistance between the carbon and the current collector has a significant effect on the conductivity of the electrochemical cell and the stability of its operation. The contact area increase of the electrode with the electrolyte leads to an increase in the rate processes occurring on the electrode surface and in the near-electrode space, which opens up prospects for increasing the energy intensity of the electrochemical system. A significant capacity increase of a water-based capacitor structure is achieved by the formation of a nanostructured dielectric layer of potassium titanate in the interelectrode space. It has been confirmed that the cell voltage cycling helps to stabilize the processes occurring in the surface layer of the electrode material at the interface and determining the range of mechanisms for transmitting electrical energy, which makes it possible to achieve higher energy intensity of the samples. Improvement of technological solutions in the field of ion-plasma technologies and the use of new perspective nanostructured materials creates the prerequisites for the creation of advanced automation and energy supply systems with a higher resource, which expands the possibilities of their use in various construction projects.

Experimental features of the intense ultra-short electric pulses exposure on similar to biological media

Experimental features of the intense ultra-short electric pulses exposure on similar to biological media

Half-metallization Atom-Fingerprints Achieved at Ultrafast Oxygen-Evaporated Pyrochlores for Acidic Water Oxidation.

The stability and catalytic activity of acidic oxygen evolution reaction (OER) are strongly determined by the coordination states and spatial symmetry among metal sites at catalysts. Herein, an ultrafast oxygen evaporation technology to rapidly soften the intrinsic covalent bonds using ultrahigh electrical pulses is suggested, in which prospective charged excited states at this extreme avalanche condition can generate a strong electron-phonon coupling to rapidly evaporate some coordinated oxygen (O) atoms, finally leading to a controllable half-metallization feature. Simultaneously, the relative metal (M) site arrays can be orderly locked to delineate some intriguing atom-fingerprints at pyrochlore catalysts, where the coexistence of metallic bonds (M─M) and covalent bonds (M─O) at this symmetry-breaking configuration can partially restrain crystal field effect to generate a particular high-spin occupied state. This half-metallization catalyst can effectively optimize the spin-related reaction kinetics in acidic OER, giving rise to 10.3 times (at 188mV overpotential) reactive activity than pristine pyrochlores. This work provides a new understanding of half-metallization atom-fingerprints at catalyst surfaces to accelerate acidic water oxidation.

Analysis of magnetic resonance contrast agent entrapment following reversible electroporation in vitro.

Administering gadolinium-based contrast agent before electroporation allows the contrast agent to enter the cells and enables MRI assessment of reversibly electroporated regions. The aim of this study was evaluation of contrast agent entrapment in Chinese hamster ovary (CHO) cells and comparison of these results with those determined by standard in vitro methods for assessing cell membrane permeability, cell membrane integrity and cell survival following electroporation. Cell membrane permeabilization and cell membrane integrity experiments were performed using YO-PRO-1 dye and propidium iodide, respectively. Cell survival experiments were performed by assessing metabolic activity of cells using MTS assay. The entrapment of gadolinium-based contrast agent gadobutrol inside the cells was evaluated using T1 relaxometry of cell suspensions 25 min and 24 h after electroporation and confirmed by inductively coupled plasma mass spectrometry. Contrast agent was detected 25 min and 24 h after the delivery of electric pulses in cells that were reversibly electroporated. In addition, contrast agent was present in irreversibly electroporated cells 25 min after the delivery of electric pulses but was no longer detected in irreversibly electroporated cells after 24 h. Inductively coupled plasma mass spectrometry showed a proportional decrease in gadolinium content per cell with shortening of T1 relaxation time (R 2 = 0.88 and p = 0.0191). Our results demonstrate that the contrast agent is entrapped in cells exposed to reversible electroporation but exits from cells exposed to irreversible electroporation within 24 h, thus confirming the hypothesis on which detection experiments in vivo were based.

Pilot study of using transcranial temporal interfering theta-burst stimulation for modulating motor excitability in rat

Transcranial temporal interference stimulation (tTIS) is a promising brain stimulation method that can target deep brain regions by delivering an interfering current from surface electrodes. Most instances of tTIS stimulate the brain with a single-frequency sinusoidal waveform generated by wave interference. Theta burst stimulation is an effective stimulation scheme that can modulate neuroplasticity by generating long-term potentiation- or depression-like effects. To broaden tTIS application, we developed a theta burst protocol using tTIS technique to modulate neuroplasticity in rats. Two cannula electrodes were unilaterally implanted into the intact skull over the primary motor cortex. Electrical field of temporal interference envelopes generated by tTIS through cannula electrodes were recorded from primary motor cortex. Theta burst schemes were characterized, and motor activation induced by the stimulation was also evaluated simultaneously by observing electromyographic signals from the corresponding brachioradialis muscle. After validating the stimulation scheme, we further tested the modulatory effects of theta burst stimulation delivered by tTIS and by conventional transcranial electrical stimulation on primary motor cortex excitability. Changes in the amplitude of motor evoked potentials, elicited when the primary motor cortex was activated by electrical pulses, were measured before and after theta burst stimulation by both techniques. Significant potentiation and suppression were found at 15 to 30 min after the intermittent and continuous theta burst stimulation delivered using tTIS, respectively. However, comparing to theta burst stimulations delivered using conventional form of transcranial electrical stimulation, using tTIS expressed no significant difference in modulating motor evoked potential amplitudes. Sham treatment from both methods had no effect on changing the motor evoked potential amplitude. The present study demonstrated the feasibility of using tTIS to achieve a theta burst stimulation scheme for motor cortical neuromodulation. These findings also indicated the future potential of using tTIS to carry out theta burst stimulation protocols in deep-brain networks for modulating neuroplasticity.

The Effects of Bipolar Cancellation Phenomenon on Nano-Electrochemotherapy of Melanoma Tumors: In Vitro and In Vivo Pilot.

The phenomenon known as bipolar cancellation is observed when biphasic nanosecond electric field pulses are used, which results in reduced electroporation efficiency when compared to unipolar pulses of the same parameters. Basically, the negative phase of the bipolar pulse diminishes the effect of the positive phase. Our study aimed to investigate how bipolar cancellation affects Ca2+ electrochemotherapy and cellular response under varying electric field intensities and pulse durations (3-7 kV/cm, 100, 300, and 500 ns bipolar 1 MHz repetition frequency pulse bursts, n = 100). As a reference, standard microsecond range parametric protocols were used (100 µs × 8 pulses). We have shown that the cancellation effect is extremely strong when the pulses are closely spaced (1 MHz frequency), which results in a lack of cell membrane permeabilization and consequent failure of electrochemotherapy in vitro. To validate the observations, we have performed a pilot in vivo study where we compared the efficacy of monophasic (5 kV/cm × ↑500 ns × 100) and biphasic sequences (5 kV/cm × ↑500 ns + ↓500 ns × 100) delivered at 1 MHz frequency in the context of Ca2+ electrochemotherapy (B16-F10 cell line, C57BL/6 mice, n = 24). Mice treated with bipolar pulses did not exhibit prolonged survival when compared to the untreated control (tumor-bearing mice); therefore, the bipolar cancellation phenomenon was also occurrent in vivo, significantly impairing electrochemotherapy. At the same time, the efficacy of monophasic nanosecond pulses was comparable to 1.4 kV/cm × 100 µs × 8 pulses sequence, resulting in tumor reduction following the treatment and prolonged survival of the animals.

Experimental investigation on high voltage electric pulse rock breaking under drilling mud conditions

High voltage electric pulse rock breaking technology is a novel and promising rock breaking technique that is environmentally friendly, efficient, and nearing industrial application. However, the drilling performance of electrode bits under varied drilling muds and the mechanism of high voltage electric pulse rock breaking remain unclear. This study entails real drilling experiments conducted on red sandstone using electrical pulse drilling (EPD) under different initial voltage peaks, electrode bits, and drilling muds to investigate the impact and mechanism of EPD. A laboratory experimental system for high voltage pulse rock breaking is established based on a 0–80 kV EPD pulse generator. Three types of electrode bits are devised, namely, petal-structural, four-point-structural, and circular-ring-structural electrode bits. The EPD experiments on red sandstone are executed under seven different drilling muds at initial peak voltages ranging from 13 to 17 kV. And the efficiency of EPD rock breaking is assessed using five quantitative indexes: rate of penetration, breaking volume, specific energy of rock breaking, and the proportion of electrical fragmentation and hydraulic-electric rock fragmentation. Furthermore, the physical parameters, i.e., density, conductivity, Zeta potential, PH, and apparent viscosity, of the seven drilling muds are measured, shedding light on the rock breaking mechanism of EPD under specific drilling mud conditions. Subsequently, the designed electrode bit is evaluated, and based on experimental phenomenon, structural optimizations of the electrode bit and EPD drilling recommendations under various drilling mud conditions in real drilling scenarios are proposed. This research is poised to offer valuable insights into the design of EPD electrode bits and the selection of drilling mud for enhancing drilling efficiency.

Kinetic analysis of an optically pumped rare gas lasing medium with a nanosecond repetitively pulsed discharge in Ar-He mixture

A kinetic model of a lasing medium for an optically pumped rare gas laser (OPRGL) was developed that accounts for the production of excited argon atoms Ar* in a nanosecond repetitively pulsed discharge (NRPD). Analytical formulas were derived for the frequency of Ar* radiation losses, population of the energy levels involved in the laser cycle and specific powers for pump absorption and lasing in the limit of bleaching of pump and lasing transitions. The formulas use the kinetic constants of the model as parameters and Ar* number density as the independent variable. Periodic solutions for number density of plasma components, pump absorption and small signal gain, specific pump absorption and lasing were obtained numerically. Mean over the NRPD period values of Ar* number density, specific pump absorption and lasing were calculated as the functions of the preset peak values of the reduced electric field E/N. Triangular electric field pulses of 80 ns FWHM duration and 200 kHz frequency were considered. Optical pumping increases Ar* loss by more than a factor of 10, due to excess spontaneous emission from Ar* levels that populates the 1s4 state of argon, resulting in a reduced NRPD plasma ionization and Ar* production. As a result, without auxiliary optical pumping from the 1s4 state that compensates this loss, the averaged across the discharge period Ar* number density decreases by a factor of 30. Moreover, the average specific heat release in plasma becomes almost equal to the specific lasing power in the acceptable operating modes, making auxiliary optical pumping mandatory for scaling of an OPRGL. The sensitivity of the results to the values of kinetic constants in the model is analyzed.

Research on simulating coal crack development under high voltage electric pulse stress waves using zero thickness cohesive elements

High voltage electric pulse (HVEP) technology has demonstrated significant potential in enhancing coal seam permeability. However, there is a notable gap in numerical simulation studies that investigate the cracks development patterns in coal under the influence of this technology. In this study, a HVEP coal rock fracturing system was utilized to conduct a physical simulation experiment of coal sample electrical fragmentation. A finite-discrete element method (FDEM) model, incorporating zero-thickness cohesive elements, was developed to simulate the process of stress wave-induced crack propagation in coal, triggered by the plasma channel. The results indicate that over time, the stress wave typically exhibits an initial rapid rise followed by an oscillatory decline. The peak value of the stress wave decreases significantly with distance, stabilizing beyond a propagation distance of 10 mm. Furthermore, the fracturing efficacy of coal by HVEP stress waves is closely linked to specific characteristic parameters: within the range of 75–125 MPa, a positive correlation exists between the stress wave peak and the complexity of the coal crack network. Reducing the stress wave loading rate can increase the crack area to some extent, although excessively slow loading rates may lead to excessive energy dissipation during propagation, which is detrimental to crack expansion. Conversely, when the ratio of β to α ranges from 1 to 100, decelerating the attenuation rate of the stress wave aids in generating stress concentration within the crack zone, thereby facilitating crack propagation. The established numerical model aims to advance understanding of HVEP’s fracturing mechanisms and enhance its application in coalbed methane extraction.

Flexible optoelectronic N-I-P synaptic device with visible spectrum perception for energy-efficient artificial vision and efferent neuromuscular system

We have designed a flexible photoelectric artificial synapse with an oxide/mixed perovskite/polymer N-I-P structure that exhibits essential synaptic plasticity. Formamidinium lead triiodide FAPbI3 perovskite doped with bromine and methylammonium (FAxMA1−xPbI2Br) is employed as the intrinsic layer to improve the optical properties of devices. Without requiring a power source in reaction to outside optical spikes, multiple pulse-dependent plasticity is reproduced on the synaptic devices, and the image's edges are sharpened using high-pass filtering. Additionally, the classical conditioning and spatiotemporal learning are copied under the electric pulse excitation. Significant negative differential resistance is evident, even after 1500 flex/flat mechanical operation. The recognition rate of letters in the visual system is as high as 92%, and the walking distance in the efferent neuromuscular system is controllable. The flexible optoelectronic N-I-P synaptic device is designed to facilitate energy-efficient information processing for neuromorphic computing.

Research Status and Prospects of High-Voltage Pulse Plasma Rock-Fracturing Technology

With the continuous development of the geological engineering field, high-voltage electric pulse plasma rock-fracturing technology has become a research hotspot in recent years. It is now widely recognized that this fracturing technology has many application prospects and great economic benefits. Through the research process of this technology, it has proven to be an efficient and new type of rock-fracturing technology, which overcomes the problems of high cost, low efficiency, high safety risk, and serious pollution associated with traditional rock-fracturing technology. Also, it has unique advantages in terms of protecting the environment and reducing damage to the surrounding buildings. This paper reviews the research history of plasma shock wave influencing factors and pulsed discharge plasma rock-fracturing technology, summarizes the research on this technology from the perspectives of the mechanism of high-voltage electric pulse plasma rock fracturing and practical application, and discusses the feasibility of this technology when applied to the field of tunnel boring as well as the future development direction. This technology can be better used in the tunnel-boring field, which can greatly improve the tunnel-boring efficiency, but at present, the research on plasma rock-fracturing-assisted tunnel boring is still in the laboratory research stage, which lacks systematic research equipment and judging indexes, and the follow-up should focus on improving the systematic research capabilities of the plasma rock-fracturing-assisted tunnel-boring equipment, and systematically and comprehensively carry out research on rock-fracturing by plasma-assisted excavation equipment.