Effect Of Dc Electric Field Research Articles

An AC and DC Electric Field Effect Based Charged Particle Focusing Scheme for Particle Beam Mass Spectrometer

Particle Beam Mass Spectrometer (PBMS) is a mass analyzer based particle sizer, features a few to hundreds of nanometer (nm) sizing capabilities in environmental pressures above hundreds of mTorr. The above feature makes the PBMS be used as in-situ process monitoring schemes for several kinds of semiconductor process equipment (e.g. Chemical Vapor Deposition). However, it still cannot be used in other process equipment (e.g. Plasma etching, Ion implantation) which requires lower process pressure conditions than the PBMS operation limits. The bottleneck of pressure limits comes from an aerodynamic lens component, which focuses incoming particles in background gas using repetitive fluidic contraction and expansion effects. These effects hard to be happened when the target particles are surrounded in molecular or transition background gas regions. In order to lower the operating pressure limits, other focusing schemes are required.In this study, an alternative particle focusing scheme which uses AC and DC electric field effects is proposed. The proposed scheme uses a stacked-ring ion funnel structure with variable AC and DC electric sources, for driving AC and DC potential variations along the funnel’s axial direction. While radial electric potential wells produced by AC frequency components induce particles’ radial position concentration to the funnel axis center, potential well depth and axial well depth steepness is controlled by AC amplitudes and DC source values.Simulation results show that with the proposed scheme, more than 50% of particle transmission efficiencies are obtained for 5 nm – 100 nm sized charged particles moving with Maxwellian velocities in molecular background region. The results come from AC electric sources with 200 Hz - 20 kHz frequency ranges and within 50 V amplitude ranges, and DC electric sources within 50 V ranges which are feasible values for hardware implementation.

DC electric field effect for frictional contact area heated by high temperature

DC electric field effect for frictional contact area heated by high temperature

Effect of Temperature Gradients and DC Electric Field on Electrothermal Convection in a Rotating Layer of Walter's-B Fluid Saturated Porous Media

Thermal convection in fluid-saturated porous media has diverse applications across geothermal energy utilisation, thermal insulation engineering, grain storage and understanding geodynamic processes. The thermal convection's physics is crucial for optimising the thermofluid system, improving energy efficiency, and enhancing our understanding of natural phenomena. The study examines how the initiation of electrothermal convection in a rotating viscoelastic fluid layer (Walter's B) is influenced by basic temperature gradients and a uniform vertical DC electric field, considering three different types of velocity boundary conditions: free-free, rigid-rigid, and lower rigid and upper free. By applying an electric field to a fluid, studying electrothermal convection helps engineers design effective cooling systems for electronics. The eigenvalue problem is solved by using the Galerkin technique. The Galerkin method is a widely used numerical technique for solving eigenvalue problems. The DC electric field effect exhibits a more stabilising effect for free-free boundaries than rigid and rigid-rigid boundaries. Moreover, the linear temperature profile exhibits a more stabilising effect than the parabolic temperature profile. The control of electrothermal convection on the system with the impact of other physical parameters is also discussed.

DC Electric Field Effect on Conductivity and Interface Charge of Oil-Paper Insulation

Understanding the effect of electric field strength on conductivity and interface charge is very important for the converter transformer design, operation and maintenance. This paper studies the DC electric field effect sensitivity on conductivity and interface charge of “liquid–solid” oil-paper insulation. Firstly, polarization and depolarization current (PDC) and conductivity of mineral oil, oil-immersed pressboard and “liquid–solid” oil-paper insulation is measured. secondly, interface charge characteristics is calculated. Last, the influence mechanism of DC electric field and moisture on interface charge density and conductivity is analyzed. Results show that PDC curve of mineral oil increases with electric field, while mineral oil conductivity decreases and then increases with DC electric field strength. PDC curve and conductivity of oil-immersed pressboard and “liquid–solid” oil-paper insulation increases with moisture content and DC electric field. Nevertheless, “liquid–solid” oil-paper insulation with low moisture content increases rapidly and then tends to be stable, while that with high moisture content keeps increasing exponentially. Interface charge density of “liquid–solid” oil-paper insulation increases with DC electric field strength and decreases with moisture content. Compared with interface charge density calculated by Maxwell-Wagner Equation (M-W Equation), error percentage in low moisture content is high, indicating that interface charge density effect on converter transformer “liquid–solid” oil-paper insulation should be taken into consideration in structure design and operation maintenance.

Control and promotion of probiotic cells' aggregation and viability using DC electric field and standing acoustic waves

Bacterial cells' long-term stability can be induced through cell aggregation. This study aimed to stimulate probiotic cells' aggregation, suspended in 10 mM KH2PO4 at 18 ± 2 °C, utilizing DC electric fields (10–100 mA) and combined electric field (40 mA) with standing acoustic waves (at a frequency range of 26 kHz to 296 kHz). It was demonstrated that the sole application of acoustic waves on the rod-shaped Bifidobacterium animalis subsp. lactis (BIFIDO) did not trigger cell aggregation. However, the application of DC electric field to BIFIDO, induced polarization and aggregation of the BIFIDO cells, as indicated by spectrophotometric measurements (OD600) and visualized by fluorescence microscopy. The aggregation of BIFIDO cells was accelerated (∼6 times) when applying simultaneously DC electric field and standing acoustic waves, due to the accumulation of the cells at the acoustic pressure nodes, and due to the polarization of the cells by dielectrophoresis (DEP) phenomenon. The synergistic effect of DC electric field and standing acoustic waves not only facilitated the aggregation of the cells, but also considerably enhanced the hydrophobicity of BIFIDO cells, without compromising their viability or altering their surface charges. Enhanced viability and stability of the aggregated probiotic cells, in comparison to the non-aggregated, was also observed. Industrial relevanceThe present study points out the application of DC electric field and Standing Acoustic waves to aggregate probiotic cells. An important attribute of aggregated cells is their greater tolerance to environmental stresses. This technology could be applied for large-scale manipulation and aggregation of cells, as for instance during fermentation, prior to drying or encapsulation of cells, or during other industrial cell treatment technologies.

Effect of DC and AC electric fields on crack healing behavior in 8 mol% yttria‐stabilized cubic zirconia polycrystal

AbstractThe effect of the flash event (FE) on microcrack healing behavior in 8 mol% yttria‐stabilized zirconia was examined at healing temperatures of 1040 and 1230°C under the direct and alternating (DC and AC) electric fields. The crack healing behavior changed depending on the factors of the electric field, healing temperature, and crack length. Although the crack healing proceeded with the temperature, the healing rate increased with the crack length, suggesting that the external energy stored as crack surface energy would provide a driving force for the crack healing. Although the crack healing occurs even under the static annealing without the electric field, the healing rate was accelerated by FE significantly more under the AC field than under the DC field. The microcracks with a length of ≈20 μm were fully healed at 1230°C only for 10 min by the FE treatment under the AC field, and the flash healing behavior was four times faster than that of the static annealing. These results suggest that the enhanced healing behavior cannot be explained only by thermal effects, and the accelerated diffusivity caused additionally by nonthermal effect under FE might contribute to the enhanced healing behavior, especially in the AC electric field.

Electrorheological effects of waxy crude oils under high-voltage AC electric field

Electrical treatment is an emerging method for improving the cold flowability of waxy crude oil by taking advantage of the electrorheological effect of the oil. Previous investigations have been focused on the effect of DC electric fields, with the effect of AC electric fields unknown. In this paper, experiments were made by exposing a waxy crude oil to AC electric fields with different frequencies, field amplitudes, and waveforms (square wave, sine wave, and triangle wave), and the viscosity and yield stress of the crude oil before and after the treatment were compared. It was found that the AC electric field could also improve crude oil cold flowability, but its electrorheological effect is somewhat weaker than that of a DC field under the same test conditions of treatment time and temperature. The lower the frequency, the stronger the effect. The essential reason could be the reduced force of charged particle migration under an AC field with a higher frequency. At the same frequency, the viscosity reduction is significantly improved with increased field strength amplitude. At the same field strength amplitude, the electrorheological effect of the three studied waveforms is ranked, from strong to weak, as square one, sinusoidal one, and triangle one, which is essentially attributed to the difference in the Root Mean Square (RMS) values of the field strength of each waveform. The higher the RMS value, the better the electrorheological effect. The main conclusion was confirmed by additional experiments using another crude oil.

Effect of Negative High-Voltage Corona Field on Hydrophilicity and Vigor of Astragalus mongolicus Seeds

This work aims to study the effect of dc negative high-voltage corona electric field on the vigor and hydrophilicity of Astragalus membranceus (Fisch.) Bge. var. mongolicus (Bge.) Hsiao seeds. The ion wind generated by the multipin pole generator at −3, −4, −5, −6, and −7 kV and the electrostatic field acted together. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${A}$ </tex-math></inline-formula> . mongholicus seeds were exposed to the electric field for 30, 60, and 90 min. Results show that the ion wind velocity increases significantly with the increase of applied voltage. Malonaldehyde (MDA), electrical conductivity (EC), and apparent contact angle (APCA) in all treatment groups decreased to different degrees compared with the control samples. MDA, EC, and APCA decreased by 56.28%, 20.89%, and 31%, respectively. The hydrophilicity of seeds treated by negative corona field was improved, and the water absorption of seeds was increased by 1.34 times. Fourier infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray (EDX) spectroscopy were used to examine the spectra, apparent morphology, and surface elements of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${A}$ </tex-math></inline-formula> . mongholicus seed coats from different treatment groups. Results showed that the ionic wind generated by the negative high-voltage corona electric field had a significant etching effect on the seed coat and enhanced the water absorption and fiber strength of hydrophilic functional groups of the seed coat.

The effect of DC electric field on the elongation growth, proton extrusion and membrane potential of Zea mays L. coleoptile cells; a laboratory study

BackgroundIn this study, we investigated the effect of an electric field, with an intensity similar to that of the Earth’s field, on plant cells growth. The molecular mechanism underlying this effect remains unclear.ResultsIt was found that the electric field, depending on the applied voltage, its duration and the polarization of the maize seedlings, stimulated or inhibited the growth of the seedling organs (root, mesocotyl and coleoptile). Moreover, it was also noticed that the gravitropic response of maize seedlings was inhibited at all voltages studied. Simultaneous measurements of growth and external medium pH show that auxin(IAA, indole-3-acetic acid)- and fusicoccin(FC)-induced elongation growth and proton extrusion of maize coleoptile segments were significantly inhibited at higher voltages. The ionic current flowing through the single coleoptile segment during voltage application was 1.7-fold lower in segments treated with cation channel blocker tetraethylammonium chloride (TEA-Cl) and 1.4-fold higher with IAA compared to the control. The electrophysiological experiments show that the electric field caused the depolarization of the membrane potential of parenchymal coleoptile cells, which was not reversible over 120 min.ConclusionIt is suggested that a DC electric field inhibits the plasma membrane H+ pump activity and K+ uptake through voltage-dependent, inwardly rectifying ZMK1 channels (Zea mays K+ channel 1). The data presented here are discussed, taking into account the “acid growth hypothesis” of the auxin action and the mechanism of gravitropic response induction.

Dependence of gain coefficient and response time on the applied electric field in LiNbO3:Fe crystal

In this paper, the characteristics of two-wave mixing in photorefractive crystal LiNbO3:Fe are theoretically and experimentally analyzed. The relationship between the gain coefficient and the external dc electric field is investigated. The effects of the external dc electric field, incident intensity and density of electron donor on the response time are analyzed It has been found that the gain coefficient can be increased by applying the external electric field when the incident intensity and beam crossing angle are 12 mW/cm2 and 15°, respectively. The response time of two-wave mixing can be reduced by enhancing the external electric field incident intensity or density of electron donor. Experimental results show that when the external electric field is increased from 0 to 8 kV/cm, the response time of LiNbO3:Fe crystal drops from 87 s to 72 s. Furthermore, the response time decreases rapidly and then slowly with the enhancement of the incident intensity. The response time reduces from 180 s to 42 s with the increase of the incident intensity when the external electric field is constant at 10 kV/cm. The response time with an external electric field is slightly shorter than that without an external electric field. The experimental results are consistent with the theoretical simulation. The present work can provide application guidance for the research of photorefractive crystals.

On the possibility of technosphere safety by superionic

The purpose of this article is an attempt to substantiate the possibility of using a new technology for cleaning the industrial atmosphere in a separate workshop of the Taldykorgan battery plant "Kainar AKB", which produces, in particular, powerful batteries for K–700 tractors for agriculture. The innovative technology of air purification proposed by us in the technosphere of the manufacture of batteries for the agricultural production complex is based on the use of transport ion-conducting properties of solid electrolytes made of stabilized zirconium dioxide. The traditional methods of industrial atmosphere purification in enterprises and factories known to us, in our opinion, are morally outdated in terms of bulky external dimensions, noise generation, and need for systematic maintenance. The installation developed by us from a superionic conductor is devoid of these disadvantages, it is low-inertia, does not create a noise effect, compact and small-sized. Our ion conducting solid electrolyte is a ceramic material in the form of pipes, test tubes, tablets, initially containing impurity cations of lower valence, such as calcium, yttrium, scandium, in comparison with zirconium. Actually, these impurity cations create the presence of vacancies or holes in the solid cubic structure of zirconium dioxide. Only oxygen anions will be transported through these vacancies under the effect of external factors, high temperature, and DC electric field. The research method is based on the measurement of the electromotive force, which is recorded at the boundary section: air/superionic/air, which is uniquely mathematically related to oxygen concentration in air stream.

Effects of an electric field applied during the solution heat treatment of the Al–Mg –Si–Cu alloy AA6111 on the subsequent natural aging kinetics and tensile properties

Abstract The effects of an external dc electric field of 0 – 5 kV/cm, applied at 475 – 550 °C during solution heat treatment (SHT) to AA6111, on the subsequent natural aging kinetics and volume fraction of precipitated clusters were determined employing resistivity. The field increased the asquenched resistivity and that during natural aging, the effect being significant from 0 to ≈0.5 kV/cm and increasing only slightly, if at all, thereafter. An Avrami-type analysis of the natural aging kinetics gave n = 0.59 ± 0.2 and k = (1.2 ± 0.8) · 10– 2 min –1, relatively independent of SHT temperature and field strength. The field increased the volume fraction of precipitated clusters which occurred during natural aging. This was attributed to the increase in solubility during SHT produced by the field. Tensile properties equivalent to those obtained by the SHT at 550 °C without a field were obtained at 500 °C with a field of only 200 V/cm, representing a reduction of 50 °C in the nominal SHT temperature.

Effect of Dc Electric Fields on Methane/Air Flame Characteristics in a Micro Confined Combustion Space

Effect of Dc Electric Fields on Methane/Air Flame Characteristics in a Micro Confined Combustion Space

Effect of DC electric field on THz radiation field and efficiency of dark hollow laser beam in plasma

In the present study, a schematic has been proposed for generating terahertz (THz) radiation by beating of two dark hollow (DH) laser beams in plasma when a DC electric field is applied with a perpendicular direction. The small field amplitude and the radiation’s efficiency produced by DH laser beams in plasma as well as DC electric generation and exertion comfortability motivated us to enhance these parameters by applying a perpendicular DC electric field. It was found that applying a DC electric field in addition to increasing the THz field amplitude and efficiency caused the generation of a special THz field, which has an exclusive pattern tunable by the variation of the electric field amplitude. It is shown that due to mutual effects between the spatial profile of the beams and the electric field, the THz radiation field and efficiency have the maximum point that can be used for the production of a desired THz frequency.

Effect of external direct current electric field on the inhibition behavior of Zn-MOFs for Cu in 0.5 mol/L NaCl solution

The effect of an external DC electric field on the inhibition behavior of Zn-MOFs in 0.5 mol/L NaCl solution for copper was investigated via electrochemical measurements and various characterization techniques. Results indicated that the corrosion inhibition efficiency of the Zn-MOFs decreased under strong electric field intensities, which went from 94.2% to 61.7%. The corrosion inhibition efficiency of the materials decreased with increasing electric field duration when maintained at a certain electric field intensity. When the electric field duration time was 6 h, 12 h, 18 h and 24 h, the corresponding efficiency was 90.4%, 86.8%, 78.2% and 61.7% respectively. The effect of an electric field on the corrosion inhibition performance of the Zn-MOFs could essentially be attributed to changes in the structure of the material framework.

Repetitively pulsed nanosecond discharge plasma decay in propane–oxygen gas mixture in the presence of a heating electric field

Plasma decay in the afterglow of a repetitively pulsed nanosecond discharge in a stoichiometric propane–oxygen mixture was experimentally investigated when a weak heating DC electric field was applied and in its absence. The discharge was ignited at room gas temperature and a pressure of 1–2 Torr and was characterized by low specific energy inputs (<0.004 eV per molecule in one pulse). Using microwave interferometry, the temporal evolution of the electron density during plasma decay was studied, and the effective recombination coefficients were obtained from data processing. It was shown that the rate of plasma decay behaved in a non-monotonic manner with increasing degree of propane oxidation; at first the decay rate grew, then passed through a maximum, fell and saturated in the limit of a large (~2000) number of pulses. In this limit, the effect of the heating DC electric field on the plasma decay decreased with approaching chemical equilibrium. Numerical simulation of the observed effects was performed for low and high oxidation degrees of propane taking into account changes in the composition of positive ions in the plasma. Good agreement was obtained between measurements and calculations of the electron density during plasma decay in these cases. It was shown that the formation of cluster ions in the discharge afterglow plays a fundamental role. The plasma decay was controlled by electron recombination with hydrocarbon cluster ion at low oxidation degree of propane and with water cluster (hydrated) ions at high oxidation degree. A hypothesis was proposed to explain the observed nonmonotonic behavior of the plasma decay rate with an increase in the propane oxidation in the discharge, based on the formation of hydrated hydrocarbon ions CxHy+(H2O)k at moderate oxidation degrees.

Effect of Ionic Wind Induced by DC Electric Field on Biogas/Air Turbulent Premixed Flame Structure

ABSTRACT Effect of DC electric field on lean premixed biogas turbulent flame structure at low and medium turbulence intensity was studied experimentally using OH-PLIF. OH signal distribution, turbulent burning velocity and flame structure geometric parameters were derived. Results show that downward electric field could broaden the downstream burned gas and push the flame tip down. The flame base is closer to the burner rim in downward electric field for the modification of thermal diffusion and flow modification caused by ionic wind. The effect on flame tip height reduction is more obvious for biogas flame with a higher CO2 ratio. According to the flame structure analysis, the turbulent burning velocity of biogas is increased slightly due to the modification of flow field by ionic wind generated by downward electric field, and the increment decreases with the increase of turbulence intensity. In addition, there’s a decrease in mean flame surface density and an increase in centerline flame brush thickness. The flame surface curvature PDF distribution is nearly not affected by the application of DC electric field. For turbulent flames, the effect of electric field is non-uniform and inconstant, which induces extra flow perturbation. This perturbation is different from turbulence, and the combined effects lead to the variation of flame structure.

Effect of an External DC Electric Field on the Order of Polymer-Capped Gold Nanorods: Formation of Smectic, Tetragonal, and Hexagonal Structures

Effect of an External DC Electric Field on the Order of Polymer-Capped Gold Nanorods: Formation of Smectic, Tetragonal, and Hexagonal Structures

Effect of DC electric field on moisture migration characteristics in oil‐pressboard

The moisture content has a great influence on the electric insulation strength of oil-pressboard. Therefore, it is very important to assess the moisture content in power transformers. There is lack of research about the effect of DC electric field on moisture migration. Here, the authors analyse the moisture migration characteristics of oil-pressboard under DC electric field. The DC electric field has a greater influence on the moisture content in the oil. Compared with no DC electric field, the moisture content in oil is reduced by 22.91 mg/L at 50°C, while it is reduced by 17.63 mg/L at 70°C. Under the same moisture content in the oil, the moisture content in the pressboard which affected by the DC electric field is higher than the Oommen curve, the maximum difference is 0.88% at 50°C, and 0.05% at 70°C. This result can provide a reference for the revision of existing moisture assessment methods.

Numerical modelling to study the effect of DC electric field on a laminar ethylene diffusion flame

An applied DC electric field was experimentally demonstrated to modify the flame structure and gas dynamic in an ethylene diffusion flame. The aim of this paper is to investigate the influence of the electric field on the flow field and its impacts on the flame behavior. A numerical study has been performed to elucidate the experimental observations and to monitor the effect of electric body force on the flame. The numerical model was validated by comparing the computed results to experimental measurements from the literature. The resulting computed flame shape was compared to a visible image taken during the experiment. The simulated OH mole fraction, the burning rate and the computed velocity and temperature are presented. The developed model proved the ability to reproduce qualitatively the experimental flame behavior when submitted to the electric field. The electric field is shown to modify the flame shape (flame tip, flame shortness and flame deformation), to promote the burning process and to improve the ion production. Results show that the modifications are due to an air entrainment acting specifically near the burner zone enhancing the mixture and changing the fluid dynamic in this region. The ionic wind is demonstrated to increase the maximum burning rate and promoting ions' formation mostly near the burner. A more detailed model (detailed ions' chemistry and soot model with charged particles, detailed electric diffusion) is necessary to gain a better understanding of the influence of electric field on diffusion combustion and soot formation.