Electrostatic Discharge Research Articles

Effect of Transient Spark Discharge and Plasma Activated Water Treatments against Fusarium graminearum Infected Wheat Grains under Laboratory Conditions

Over the last decade, more and more attention has been paid to applications of non-thermal plasma in agriculture, where it is used to decontaminate various microorganisms and to improve the seed germination. In this study, we present the results of a newly developed point-to-ring NTP transient spark discharge apparatus (NTP), plasma activated water (PAW) and their combined treatment on Durum wheat and Common wheat grains under laboratory conditions. Transient spark discharge treatment was used as direct treatment while indirect treatment of wheat grains was performed by PAW produced in point-to-plane NTP transient spark apparatus. We found that the degree of grain surface decontamination was in order NTP > PAW > combined treatment. In the case of Durum wheat grain germination, all treatments increased germination with increasing exposure times, while in the case of Common wheat, PAW treatment and combined treatment did not significantly increase the grain germination. In conclusion, plasma treatment has enormous potential for use in agriculture and its possibilities need to be fully explored.

Discharge mitigation methods in MPGD-based detectors

This work reviews various methods used to minimize the probability of discharge occurrence in MPGDs or to mitigate the effect of spark discharges on the detector system. These include techniques that can reduce the probability that the fundamental discharge limits of MPGD structures are reached during detector operation, methods based on the HV scheme optimization, or the implementation of resistive electrodes to enhance local discharge quenching capabilities in an amplification structure. In addition, design optimization and quality control methods to ensure stable, long-term operation of an MPGD-based detector, are considered.

Effect of Ethanol and Iso-Octane Blends on Isolated Low-Temperature Heat Release in a Spark Ignition Engine

<div>Low-temperature heat release (LTHR) is of interest for its potential to help control autoignition in advanced compression ignition (ACI) engines and mitigate knock in spark ignition (SI) engines. Previous studies have identified and investigated LTHR in both ACI and SI engines before the main high-temperature heat release (HTHR) event and, more recently, LTHR in isolation has been demonstrated in SI engines by appropriately curating the in-cylinder thermal state during compression and disabling the spark discharge. Ethanol is an increasingly common component of market fuel blends, owing to its renewable sources. In this work, the effect of adding ethanol to iso-octane (2,2,4-trimethylpentane) blends on their LTHR behavior is demonstrated. Tests were run on a motored single-cylinder engine elevated inlet air temperatures and pressures were adjusted to realize LTHR from blends of iso-octane and ethanol without entering the HTHR regime. The blends were tested with inlet temperatures of 40°C–140°C at equivalence ratios of 0.5, 0.67, and 1.0 with boosted (1.5 barA) conditions. The measured LTHR decreased with increasing ethanol content for all conditions tested; iso-octane–ethanol blends with above 20% ethanol content (by volume) showed minimal LTHR under engine conditions. These net effects resulted from the combination of thermal effects (charge cooling) and chemical effects (reactivity changes at low temperatures). The effect of temperature, pressure, fuel composition, and equivalence ratio on ignition delay times calculated from chemical kinetic modeling are presented alongside pressure–temperature trajectories of the in-cylinder gases to explain the trends. The underlying cause of the trends is explained by using a sensitivity analysis to determine the contribution of each reaction within the chemical kinetic mechanism to first-stage ignition, revealing the effect of introducing ethanol on the OH radical pool and resulting LTHR intensity.</div>

Numerical simulation of hybrid nanofluid flow consisting of polymer–CNT matrix nanocomposites subject to Lorentz force and heat source/sink across coaxial cylinders

The hybrid nanofluid (HNF) flow consists of polymer/CNT matrix nanocomposite material (MNC) across coaxial cylinders is numerically described in this study. The HNF flow is inspected under the consequences of thermal radiation, exponential heat source/sink and viscous dissipation. The HNF is prepared by adding polymer/CNT MNC in water. MNCs are highly productive elements with unique designs and properties. The MNCs are widely used in biomedicine and electrical applications due to their exceptional thermophysical properties. Based on their exceptionally high electrical conductivity, CNT/polymer nanoparticles (NPs) are also utilized as shielding for electrostatic discharge and electromagnetic interference (EMI). The HNF flow is modeled with the help of energy, continuity, and momentum equations. MATLAB package bvp4c is used to numerically handle the modeled equations. It has been perceived that the intensifying numbers of polymer/CNT MNC will lessen the fluid velocity and temperature profile in cases of both nanofluid and HNF.

Self-powered organic pollutants degradation in wastewater by photocatalytic ozonation based on triboelectric nanogenerator

It is of great significance to explore innovative ways to degrade organic pollutants in wastewater. Here, for the first time, we report a self-powered photocatalytic ozonation water purification system for removing organic pollutants in aquatic environment. A rabbit fur-based rotary triboelectric nanogenerator (RR-TENG) is designed as the power supply of water purification system. As a new TENG-based ozone generation method, spark-surface dielectric barrier discharge (Spark-SDBD) is proposed, which is composed of spark discharge device and surface dielectric barrier discharge (SDBD) device in series and can generate ozone to a maximum concentration of 36.4 mg/m3. Rhodamine B and ciprofloxacin, two typical organic compounds, are selected as simulated pollutants in wastewater, and P25 particles loaded on nickel foam are used as the photocatalyst. Ozone is continuously introduced into the polluted solution through an aeration device, coupled with photocatalysis. Within 80 minutes, it can be observed that Rhodamine B has 100% decolorization and ciprofloxacin is degraded to 99%. This work broadens the field of water purification and provides an effective way to create a cleaner and safer aquatic environment.

Core-shell structured α-AlH3/Fe2O3 thermite with improved heat-release and combustion performance

Thermites are widely used in propellants, explosives and ignition materials because of their high heat release rate and good combustion efficiency. Structural control over thermites to achieve improved performance leads to a promising research area. Among these, core-shell structured composites have attracted wide attention due to their excellent properties and close contact among components. Herein, core-shell structured α-AlH3/Fe2O3 thermites were prepared, which exhibit high heat-release and excellent combustion performance. At an equivalence ratio of 2.0, the core-shell structured α-AlH3/Fe2O3 has the most heat release (1213.8 J/g) and the lowest reaction activation energy (147.5 kJ/mol). The ignited combustion performance of α-AlH3/Fe2O3 was notably strengthened by the shorter ignition delay period (11 ms). Interestingly, the core-shell structured α-AlH3/Fe2O3 was less sensitive to electrostatic discharge, which suggests that the core-shell structured α-AlH3/Fe2O3 reaches the goal of high energy release and electrostatic safety. The core-shell thermite system with α-AlH3 as metal fuel could provide an efficient alternative to hunt for thermites with high reactivity.

Разработка и исследование имитационной модели мультикамерного разрядника для грозозащитного троса

Optical fiber overhead ground wire (OPGW) is an effective solution for laying mainline digital communications along high-voltage power lines. It allows you to use the existing infrastructure of the power grid and ensure the transfer of a large amount of data. The flow of lightning currents and short-circuit currents can cause a violation of the thermal resistance of the fiber and a deterioration of its performance. When the OPGW is insulated through an insulator shunted by a spark gap, during operation it is possible to change the distance in the discharge gap due to the displacement of the electrodes in the plane. Also, when the short circuit location is close, multiple overlaps will occur and as a result, short circuit current will flow through the OPGW. Thus, the article considers the possibility to use a device with a multielectrode system developed on the principle of a multichamber spark gap as a replacement of the spark gap to increase the reliability of the unit with an isolated OPGW suspension. Modeling of the device has been carried out in the ANSYS Maxwell software package, the mathematical apparatus of which is based on the use of Maxwell's differential equations and the finite element method, which allows performing numerical modeling with sufficiently high accuracy. A simulation model of a multichamber spark gap has been developed in the ANSYS Maxwell software package and calculations of electrical characteristics have been performed. For the electrode system of a multi-chamber arrester, an uneven distribution of the applied voltage across the spark discharge gaps of the chambers is determined. It is shown that when a voltage is applied to a spark gap, the highest electric field strength occurs between the first and second electrodes, and then a cascade of discharge gaps occurs, which provides the required low discharge voltages of the spark gap as a whole. The developed simplified simulation model of a multi-chamber arrester has shown all the necessary conditions for cascade imaging of the voltage distribution and the electric-field strength of various electrode options. Based on the research conducted electrodes geometry is identified for smart prototype development and ongoing multi-chamber arrester research.

Electrostatic discharge mechanisms and dynamic characteristics of different polarity powders in the Silo

Electrostatic discharge in powder silos poses a significant safety hazard due to the risk of fire or explosion. However, the underlying discharge mechanisms are not fully understood. This study aims to improve the comprehension of electrostatic discharge dynamics and mechanisms by introducing a fluid discharge model for charged powder silos. The model validation is carried out by examining discharge patterns and electric field variations. The investigation of the electrostatic field and potential distribution prior to discharge helps to comprehend the discharge conditions. The discharge modes and evolution laws of different polarity powders are explored to reveal disparities in discharge phenomena. These disparities are further scrutinized in relation to electron density, space charge, electric field, and potential. To elucidate the discharge mechanism, the electric field distortion caused by space charge, electron existence time, and migration law are analyzed. The electrostatic and diffusion effects are the main reasons for the discharge differences.

Effect of Silicone Rubber on the Properties of Epoxy/Recovered Carbon Black (rCB) Conductive Materials

The primary focus of this study is to investigate the effect of silicone rubber (SR) content on the mechanical, thermal, electrical conductivity, and morphological properties of epoxy/recovered carbon black (rCB) conductive material. The conductive material is used to produce the electrostatic discharge (ESD) tray for the electronic packaging industry. This study investigated the effect of silicone rubber content (0, 5, 10, 15, and 20 vol.%) on the properties of epoxy/SR/rCB conductive materials, with the rCB content fixed at 15 vol.% for its optimum electrical conductivity. The silicone rubber acts as a toughening agent for epoxy. Through the fracture toughness result, it can be identified that silicone rubber plays a role in improving the toughness properties of the epoxy/SR/rCB conductive material. The optimum results for mechanical properties were recorded at 5 vol.% SR. The addition of SR to the epoxy matrix enhances the electrical properties of the epoxy/SR/rCB conductive material. The effect of thermal aging on epoxy/SR/rCB conductive materials was also studied to determine the properties of the conductive material materials at high temperatures for a long period of time. After thermal aging, the mechanical, thermal, electrical conductivity, and morphological properties of the epoxy/SR/rCB conductive material were slightly reduced.

Highly flexible porous indium-tin-oxide coating with enhanced atomic oxygen and electrostatic discharge resistance

Polyimides (PI) are commonly used in spacecraft in low Earth orbit (LEO) due to their flexibility. However, they are susceptible to erosion caused by atomic oxygen (AO) and electrostatic discharge (ESD) induced by plasma in the harsh LEO environment. Indium-tin-oxide (ITO), owing to its excellent electrostatic and AO resistance, has emerged as the most promising inorganic protective coating for PI in LEO applications. But the inherent rigidity of ITO and the high-temperature annealing process commonly required for synthesis make it challenging to employ ITO as flexible polymer substrates. In this work, we have synthesized the porous ITO layer with a low-temperature (≤150 °C) method and combined it with layer double hydroxides (LDHs) to enhance the flexibility, AO resistance, and ESD protection of the coating. The porous ITO in combination with LDHs layers effectively improve the flexibility (after 20,000 bending cycles without failure problem), AO resistance (erosion yield down to -0.102 × 10−26 cm3/atom under an exposure dose of 5.22 × 1021 atoms/cm2) and ESD resistance properties (sheet resistance around 202 kΩ/sq). The synthesis method proposed avoids the high-temperature annealing and the residual stress effect on the coating's flexibility. This work provides an efficient approach to realizing flexible and protective coating on polymers for long-lasting spacecraft electronic devices in low Earth orbit.

Characterization of Sand and Dust Pollution Degradation Based on Sensitive Structure of Microelectromechanical System Flow Sensor.

The effect of sand and dust pollution on the sensitive structures of flow sensors in microelectromechanical systems (MEMS) is a hot issue in current MEMS reliability research. However, previous studies on sand and dust contamination have only searched for sensor accuracy degradation due to heat conduction in sand and dust cover and have yet to search for other failure-inducing factors. This paper aims to discover the other inducing factors for the accuracy failure of MEMS flow sensors under sand and dust pollution by using a combined model simulation and sample test method. The accuracy of a flow sensor is mainly reflected by the size of its thermistor, so in this study, the output value of the thermistor value was chosen as an electrical characterization parameter to verify the change in the sensor's accuracy side by side. The results show that after excluding the influence of heat conduction, when sand particles fall on the device, the mutual friction between the sand particles will produce an electrostatic current; through the principle of electrostatic dissipation into the thermistor, the principle of measurement leads to the resistance value becoming smaller, and when the sand dust is stationary for some time, the resistance value returns to the expected level. This finding provides theoretical guidance for finding failure-inducing factors in MEMS failure modes.

Modeling and optimization of energy consumption in wire cut electrical discharge machining

WEDM (Wire Electrical Discharge Machining) is widely implemented in the manufacture of dies and challenging materials due to its use of spark discharge to shape a workpiece. However, existing research focuses primarily on enhancing processing efficiency, accuracy, and quality, with limited investigation into energy conservation and emissions reduction during processing. This paper constructs an energy consumption model to forecast energy usage during electric machining and proposes a low energy consumption optimization model founded on processing parameters. A case study revealed that the energy consumption model is 98.06 % accurate throughout the processing process and at least 92 % precise in predicting energy consumption for a single process. Upon utilizing the low energy consumption optimization model, the results show a reduction in energy consumption and carbon emissions by 11.5 % and 5.74 %, respectively, compared to traditional methods. The models presented in this paper can enhance EDM machining efficiency while concurrently minimizing energy consumption and carbon emissions, thereby supporting the adoption of energy-saving and efficient practices in electric machining.

In-situ construction of functional carbon layer on the plasma electrolytic oxidation-pretreated Ti-6Al-4V alloy to enhance anti-static properties

Thermal control coatings prepared by plasma electrolytic oxidation (PEO) have shown broad application potential, especially in the aerospace field. However, the high insulation nature results in charge accumulation during the real application in spacecraft, aggravating the risk of electrostatic discharges and endangering equipment's safety. Herein, a functional anti-static thermal control composite coating on the surface of Ti-6Al-4V alloys was constructed by preparation route involving in-situ polymerization and carbonization of polydopamine (PDA) on the PEO layer. After the introduction of carbonized PDA, the composite coating retained the pristine porous structure of the PEO coating with improved crystallinity. Notably, the consecutive functional carbon layer ingrates the graphite nanocrystals and N-doped graphite to achieve high conductivity and then renders the composite coating with the lowest volume resistivity (6.04 × 104 Ω m) and surface resistance (9.0 × 107 Ω/□). Moreover, the two-step prepared coating showed high absorption (200–2500 nm, 0.929) and emission (2–16.6 μm, 0.921) along with excellent stability at high temperature (∼200 ℃) and low temperature (∼−200 ℃) even over 48 h. This contribution reveals a promising direction to widen the practical application of the PEO thermal control coating.

Understanding and Controlling Electrostatic Discharge in Triboelectric Nanogenerators.

Triboelectric nanogenerators (TENGs) have been widely used to harness various forms of mechanical energy for conversion to electrical energy. However, the contentious challenge in characterising TENGs is the lack of standard protocols for assessing mechanical-to-electrical energy conversion processes. Herein, macroscopic signal analysis is used to identify three key charging events within triboelectric signals: charge induction (CI), contact electrification (CE), and electrostatic discharge (ESD). By considering two phases of motion during contact-separation (approach and departure of the contact materials), CI arising from the motion of bound surface charge (varying electric field) between opposing contact materials is shown to dominate the measured displacement current signal, rather than the process of CE itself. Furthermore, the conventional signal (i. e., voltage, current, charge) interpretation of CE and CI during approach and departure phases is re-assessed, to indicate that the sudden spike of current often observed immediately prior to contact (or after separation) arises from polarity inverting electrostatic discharge (ESD). This aspect of the measured triboelectric effect, which is often ignored, is crucial for the design of TENGs and hence, techniques to enhance the understanding and control over the stochastic occurrence of ESDs is explored. The methods proposed for the deconvolution of the macroscopic signal components of TENGs, and mitigation of ESD occurrences, will allow for precise quantification of the associated charging events. The applications of this study will template the design and development of future super-TENGs with optimised energy conversion capabilities.

Assessment of electrostatic discharge sensitivity of nitrogen-rich heterocyclic energetic compounds and their salts as high energy-density dangerous compounds: A study of structural variables

Nitrogen-rich heterocyclic energetic compounds (NRHECs) and their salts have witnessed widespread synthesis in recent years. The substantial energy-density content within these compounds can lead to potentially dangerous explosive reactions when subjected to external stimuli such as electrical discharge. Therefore, developing a reliable model for predicting their electrostatic discharge sensitivity (ESD) becomes imperative. This study proposes a novel and straightforward model based on the presence of specific groups (–NH2 or -NH-, −N=N+−O− and –NNO2, -ONO2 or -NO2) under certain conditions to assess the ESD of NRHECs and their salts, employing interpretable structural parameters. Utilizing a comprehensive dataset comprising 54 ESD measurements of NRHECs and their salts, divided into 49/5 training/test sets, the model achieves promising results. The Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and Maximum Error for the training set are reported as 0.16 J, 0.12 J, and 0.5 J, respectively. Notably, the ratios RMSE(training)/RMSE(test), MAE(training)/MAE(test), and Max Error(training)/Max Error(test) are all greater than 1.0, indicating the robust predictive capabilities of the model. The presented model demonstrates its efficacy in providing a reliable assessment of ESD for the targeted NRHECs and their salts, without the need for intricate computer codes or expert involvement.

Comparison of Single Event Effect and Space Electrostatic Discharge Effect on FPGA Signal Transmission

Comparison of Single Event Effect and Space Electrostatic Discharge Effect on FPGA Signal Transmission

Ferroelectric Domain Wall Delayer and Low-Dropout Regulator.

A switching-type power converter providing an accurate and stable switching output voltage against line/load variations and power supply ripple is mostly complicated in system-on-chip power management integrated circuits (PMICs) within a limited occupation area. Here we fabricated domain wall (DW) nanodevices using an X-cut LiNbO3 thin film on silicon. The domain switching event occurs after a delay time predicted by Merz's law under the applied voltage. But the output current is irrespective of the applied voltage and can be adjusted by conducting wall width as well as input resistance in the circuit. The regulating currents appear repetitively across the volatile interfacial domains between the nanodevice and electrode under intermittently applied voltages. A wall-current-limited domain switching model is developed to explain the phenomenon. The multifunctional DW nanodevices with smaller occupation areas can serve as compact low-dropout regulators in PMICs, time-domain delayers in energy-efficient neural network systems, and on-chip electrostatic discharge protection besides nonvolatile memories and selectors.

Boundary fluid constraints during electrochemical jet machining of large size emerging titanium alloy aerospace parts in gas–liquid flows: Experimental and numerical simulation

Large size titanium alloy parts are widely used in aerospace. However, they are difficult to manufacture using mechanical cutting technology because of severe tool wear. Electrochemical jet machining is a promising technology to achieve high efficiency, because it has high machining flexibility and no machining tool wear. However, reports on the macro electrochemical jet machining of large size titanium alloy parts are very scarce, because it is difficult to achieve effective constraint of the flow field in macro electrochemical jet machining. In addition, titanium alloy is very sensitive to fluctuation of the flow field, and a turbulent flow field would lead to serious stray corrosion. This paper reports a series of investigations of the electrochemical jet machining of titanium alloy parts. Based on the flow analysis and experiments, the machining flow field was effectively constrained. TB6 titanium alloy part with a perimeter of one meter was machined. The machined surface was smooth with no obvious machining defects. The machining process was particularly stable with no obvious spark discharge. The research provides a reference for the application of electrochemical jet machining technology to achieve large allowance material removal in the machining of large titanium alloy parts.

MEMS sensitive structure sand and dust friction contamination test and electrical variation characteristics

The impact of dust pollution on the sensitive components of Micro-Electro-Mechanical Systems (MEMS) has been a hot topic in current reliability research. However, previous studies have rarely focused on the fundamental analysis of the influence of dust pollutants on the sensitive components of MEMS, and these research results lack universality. This paper aims to present experimental results on the electrical characteristic changes of MEMS thermal sensitive resistors based on dust friction, providing a more detailed description and explanation. Through dust friction experiments, we investigated the effects of dust particle size and relative humidity on the electrical characteristics of MEMS devices. We chose the resistance value output as the electrical characteristic parameter, based on the performance exhibited during the dust friction experiments. We conducted a detailed analysis of the reasons for the changes in the electrical characteristic parameters. The research results showed that when dust particles settle on the device, the failure mode of the device manifests as resistance drift. The inducing factor is the electrostatic current generated by the friction between dust particles, which enters the sensitive components through the principle of electrostatic dissipation. The measurement principle leads to changes in the resistance value measurement, although the actual resistance value does not change. The magnitude of this electrostatic current is directly proportional to the size of the particles and inversely proportional to the relative humidity. This finding provides theoretical guidance for identifying failure-inducing factors in MEMS failure modes.

Experimental investigation to assess the surface integrity in WEDM of Al-based hybrid composite material

Aluminum-based hybrid composites are used in various engineering applications due to their unique properties, such as high strength, good wear resistance, excellent corrosion resistance, and low density. Aluminum metal matrix (AMMC) composites reinforced with ceramic particles can be more difficult to machine than traditional aluminum alloys because of their increased hardness and abrasiveness. Wire electric discharge machining is a non-traditional machining process that uses a thin metal wire, typically made of molybdenum, brass or tungsten to cut through a workpiece using electrical discharge sparks. This process is useful for precision machining of complex shapes and profiles in hard or difficult to machine materials. WEDM is a commonly used process for cutting Al-SiC-ZrO2 HAMMCs due to their hardness and difficulty in machining using conventional techniques. The present study examines the relationship between machining parameters like pulse on time (TON), pulse off time (TOFF), peak current (IP) and wire feed (WF) and material removal rate (MRR) and surface roughness ( Ra) for Al-SiC-ZrO2 in WEDM. The Box-Beckham Design was used to plan the experiments, and response surface method was employed to develop the models. The pulse duration, TOFF, IP, and quadratic terms of [Formula: see text] and [Formula: see text] are the most influential factors of the MRR. The TON, IP and interaction term (TON × IP), and [Formula: see text] were the most significant factors for Ra. Multi-response optimization of process parameters was obtained using the desirability function approach. Furthermore, the machined samples were analyzed for surface integrity using SEM techniques. The prediction from this model validated the confirmation results.