Electrode Voltage Research Articles

Electrochemical Precipitation Energy‐Assisted Aqueous Battery with High Voltage and High Electrode Utilization

Increasing battery voltage and electrode utilization is of great significance for improving the energy density of aqueous battery. Herein, for the first time, this work introduces an integrated design strategy to regulate electrode potential and improve electrode utilization based on the concept of electrochemical precipitation energy. By coupling precipitation reaction with original electrode reaction, the Gibbs free energy change () of the precipitation reaction is coupled to battery reaction's , thereby altering battery's voltage. Besides, the electrode reaction changes to solid‐to‐solid reaction after coupling with precipitation reaction, which can improve electrode utilization. The potential of Cu is reduced from 0.34 to −0.96 V (the lowest value among all the reported Cu anode) with a Cu utilization of 87.93% (without additional copper in electrolyte) by coupling Cu2S's precipitation reaction. Furthermore, the potential of I2 is increased from 0.54 to 0.65 V (I2/CuI) and 0.73 V (I2/PbI2) by coupling precipitation reaction of CuI and PbI2 and the shutting effect of I3− is also limited. As proof of concept, a full Cu2S battery (cathode: S/Cu2S, anode: Cu/Cu2S) is designed with average discharge voltage of 1.12 V, which is the highest value among all the Cu‐based aqueous batteries. Due to the certain universality of this strategy, this work provides a new path to regulate the electrode reaction potential and improve electrode utilization.

Time Resolved Observation of Streamer Discharges in Dielectric Barrier Discharge by Highly Sensitive Camera and Image Analyzing Procedure

ABSTRACT In dielectric barrier discharge (DBD) type ozone generators, improving energy efficiency, or ozone generation efficiency, is an active field of research. In ozone generation by a DBD device, numerous micro-discharges consisting of streamer channel and surface discharge are generated in a discharge gap, and ozone is generated in these discharges. Since streamer channel and surface discharge are considered to affect ozone generation characteristics, it is important to quantitatively evaluate the generation aspects of these discharges. In this study, we developed a method to extract streamer channel and surface discharge from the grayscale value distribution of the micro-discharges photograph taken from the top side of the DBD device, which consists of a transparent high voltage electrode and a metal electrode, using an image-analyzing procedure and a high-sensitivity camera equipped an image intensifier. In the method, by applying appropriate thresholding methods, binary images of micro-discharges and streamer channels can be generated from the micro-discharge photograph. Statistical analysis of these binary images enabled the estimation of the average projected area diameters of streamer channels and the average lengths of surface discharges. This approach also allowed for time-resolved observations of the number of streamer channel per unit discharge area (streamer channel density), their average projected area diameter, and the average length of surface discharge. The findings from time resolved observation revealed that a positive correlation between the streamer channel density and the magnitude of the discharge current density. Moreover, the magnitude or polarity of the discharge current did not influence the average projected area diameter of streamer channels. However, the average length of surface discharge slightly decreased with increasing streamer channel density.

Boosting Electrocatalytic Hydrogenation of Phenylacetylene via Accelerating Water Electrolysis on a Cr-Cu2O Surface.

Electrochemical alkyne reduction with H2O as a hydrogen source represents a sustainable route for value-added olefin production. However, the reaction efficiency is hampered by the high voltage and low activity of Cu electrodes due to their weak adsorbed hydrogen (*H) generation property. In this article, we present the enhanced electrocatalysis of phenylacetylene to styrene over a highly dispersive Cr-doped Cu2O nanowire (Cr-Cu2O) cathode. The Cr-Cu2O demonstrates improved catalytic activity compared to pure Cu2O, achieving a high conversion of about 94.7% and a selectivity of 87.9% with a Faraday efficiency of 64.5% at a low potential of -1.15 V vs Hg/HgO. The combination of electrochemical characterization techniques and theoretical calculations demonstrated the key role of introduced Cr atoms in lowering the activation energy barrier of surface water electrolysis to *H and facilitating the adsorption of phenylacetylene, which promotes the effective hydrogenation of phenylacetylene with *H via an electrocatalytic hydrogenation mechanism. In short, this work provides a feasible strategy to enrich interfacial *H, thus improving the semihydrogenation performance of phenylacetylene.

Production and research of Nickel powders by grinding metal waste of Nickel grade PNK-0T1 in kerosene

Purpose. Production and research of nickel powders by grinding metal waste of nickel grade PNK-0T1 in kerosene.Methods. Nickel powder from PNK-0T1 nickel metal waste in aviation kerosene of the TS-1 brand was obtained with the following electrical parameters of the installation: capacitance of capacitors 44.0-45.5 pF; electrode voltage from 115-120 V; pulse repetition frequency 60-65 Hz. The resulting nickel powder was examined by various methods. Microanalysis of powder particles was carried out using a scanning electron microscope QUANTA 600 FEG. The analysis of the size distribution of powder particles was obtained using the particle size analyzer Analysette 22 NanoTec. The X-ray spectral microanalysis of the powder particles was carried out using an energy dispersive X-ray analyzer from the EDAX company, integrated into a scanning electron microscope QUANTA 600 FEG.Results. Based on the conducted experimental studies, a new method for producing nickel powder has been devel-oped, characterized in that the powder is obtained by electroerosive dispersion of nickel metal residues of the PNK- 0T1 brand in aviation kerosene of the TS-1 brand with a capacitance of 44.5 UF capacitors, an electrode voltage of 120 V and a pulse frequency of 65 Hz, which provides, at low energy costs, the production of new nickel powder materials suitable for industrial use. It has been experimentally established that the shape of the particles of the ob-tained nickel powders is mainly spherical and elliptical. Carbon is present on the surface of nickel particles. The phases of α-modification nickel and β-modification nickel are marked in the phase composition of the particles.Conclusion. The conducted research will make it possible to select the most rational field of practical application of the electroerosive nickel powder.

ЕЛЕКТРОСТАТИЧНЕ ПОЛЕ В КАМЕРІ БАР’ЄРНОГО РОЗРЯДУ ДЛЯ ОЧИЩЕННЯ ВОДИ З УРАХУВАННЯМ ОКРЕМИХ ВОДНИХ КРАПЕЛЬ

The use of pulsed dielectric barrier discharge (DBD) for water purification via low-temperature plasma (LTP) is a promising technology. DBD enables the purification of water in a droplet-film state from organic contaminants by generating highly reactive molecules (OH radicals, O, H2O2, and O3 molecules) produced in LTP upon contact with water. A two-dimensional model was developed to calculate the electrostatic field in the DBD discharge chamber (DC), which includes two electrodes, a dielectric barrier, two water droplets or streams in the air gap, and water films. The model employs Laplace’s equation for the electrostatic field with periodic boundary conditions. Expressions were proposed for determining the length of the symmetric part of the DC and setting the voltage on the electrodes with a constant droplet surface area and a constant average electric field intensity in the air gap, independent of droplet radius. The study investigates the dependence of the electrostatic field energy and DC capacitance on the droplet radius and their mutual positioning along the DC length. Changes in electrode voltage and droplet density per unit DC length relative to droplet radius are demonstrated. An analysis of the electric field distribution, DC capacitance, and stored energy was conducted. The average electric field intensity on the surfaces of droplets and water films was examined. The electric forces acting on the droplets were determined using Maxwell's stress tensor. An expression was derived for calculating the recommended amount of water in the form of droplets or streams per unit dimensions of the DC to achieve a more uniform distribution of the electric field intensity within the DC and to minimize the impact of electric forces on the droplets. Ref. 18, fig. 7.

Optimization of Electron Beams for Ion Bombardment Secondary Emission Electron Gun

Abstract Electron beam fluorescence technology is an advanced non-contact measurement in rarefied flow fields, the fluorescence signal intensity is positively correlated with the electron beam current. The ion bombardment secondary emission electron gun is suitable for the technology. To enhance the beam current, COMSOL simulations and analyses were con-ducted to examine plasma density distribution in the discharge chamber under the effects of various conditions and the electric field distribution between the cathode and the spacer gap. The anode shape and discharge pressure conditions were optimized to increase plasma density. Additionally, an improved spacer structure was designed with the dual purpose of enhancing the electric field distribution between the cathode-spacer gap and improving vacuum dif-ferential effects. This design modification aims to increase the pass rate of secondary elec-trons. Both simulation and experimental results demonstrated that the performance of the optimized electron gun was effectively enhanced. When the electrode voltage remains con-stant and the discharge gas pressure is adjusted to around 8 Pa, the maximum beam current was increased from 0.9mA to 1.6 mA.

Investigating the Degradation Behavior of Silicon Anodes for Lithium-Ion Batteries

Silicon (Si), which delivers higher capacity than that of graphite, is an adequate material for enhancing the energy densities of lithium-ion batteries (LIBs). However, rapid capacity deterioration has made it difficult for practical use and commercialization. Furthermore, there is limited understanding regarding the degradation conditions and mechanisms of Si anode. Thus, our study aims to elucidate the degradation behavior and conditions of Si anodes while exploring the underlying degradation mechanisms.To investigate the degradation conditions of Si anodes, we conducted electrochemical experiments on NCM||Si full cells under various conditions. Cycling under sparse and ample electrolyte conditions was compared. It revealed stable cycling up to 400 cycles under sufficient conditions, while a rapid deterioration was observed after 200 cycles under sparse conditions. Additionally, we compared cycling performance under room temperature and elevated temperature conditions. Unlike conventional graphite-based LIBs, which typically exhibit more unstable cycling at high temperatures than room temperatures, NCM||Si full cells demonstrated more stable cycling behavior at elevated temperatures. While a sharp degradation occurred after approximately 200 cycles at room temperature, high temperatures yielded a remarkable 99.8% Coulombic efficiency and stable cycling beyond 300 cycles. Moreover, cycling performance was compared at low and high C-rates. At low C-rates, lifetimes exceeding 300 cycles were observed, whereas at high C-rates, rapid degradation commenced around 250 cycles. Through degradation condition experiments, we confirmed that Si anodes experience accelerated degradation with sparser electrolytes, lower temperatures, and higher C rates.Conditions of low temperature and high C-rate kinetically limit the movement of electrons and Li ions. Therefore, we hypothesized that the observed degradation behavior of Si may be attributed to restricted kinetics. To investigate this, we conducted Electrochemical impedance spectroscopy (EIS) measurements on Si, Si/Gr composite, and graphite (Gr) anodes across various states of charge (SOC). Our findings revealed pronounced differences in resistance behavior among these materials throughout the lithiation process. While graphite exhibited a linear resistance increase with lithiation, the Si/Gr composite maintained low resistance. However, pure Si anodes exhibited low resistance up to SOC60 but sharply increased resistance, quadrupling at SOC80. This observation suggests that Si encounters a significant kinetic barrier at high SOC ranges, which likely serves as a primary trigger for degradation.To enhance our comprehension of the degradation mechanism, we examined electrode surfaces post-cycling through scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). In the degraded Si electrode after 200 cycles, we observed pits scattered throughout the electrode surface which appeared to result from repeated expansion and contraction cycles. Furthermore, through EDS image analysis, we noted a significant increase in F peak content in areas where the Si peak had decreased. These observations suggest a correlation between the degradation of Si electrodes and an increase in side-reaction with electrolytes.It is known that Si undergoes a structural transformation from amorphous to crystalline, forming an over-lithiated structure, within a voltage range of less than 50 mV. Unlike graphite, which undergoes lithiation by intercalation, Si undergoes lithiation by chemical transformation, resulting in different products depending on the operating voltage. Therefore, understanding the actual driving voltage range of Si anodes is crucial for deducing the products of Si during charging and discharging. Thus, we conducted a three-electrode experiment in NCM||Si full cells. During the charging and discharging, the actual operating voltage of the Si electrode was observed to range from 0.031V to 2V. Similarly, in NCM||SiGr full cells, the actual operating voltage of the SiGr electrode ranged from 0.073V to 0.85V. Given that charging and discharging of the Si electrode occur even below 50mV, it suggests the presence of overcharged crystalline Si.To confirm the existence of this crystalline Si, we additionally conducted X-ray diffraction (XRD) and dQ/dV analysis. XRD analysis of degraded electrodes exhibited that as the cycle increased, indicating accelerated degradation, the peak of crystalline Si increased. The trend of increasing crystalline peak with progressing degradation was also confirmed through dQ/dV analysis.In conclusion, We observed the degradation behavior on Si electrodes and confirmed that the generation of over-lithiated crystalline Si is the main degradation cause. This discovery is expected to contribute to the future development of Si-based LIBs by providing valuable insights into achieving long cycles of Si anodes.

Theoretical Analysis of Carbon Deposition in the Fuel Electrode of a Reversible Solid Oxide Cell

In this presentation, we aim at analyzing the changes of Gibbs free energy of carbon deposition reactions in a reversible solid oxide cell (RSOC) that utilizes a mixture of CO and CO2 in its fuel electrode compartment, operating either in fuel cell or electrolysis mode. The thermodynamics analysis was carried out by using oxygen chemical potential at the interface between the electrolyte and fuel electrode, µO2 FE|EL , and a 1-dimensional model is established to calculate µO2 FE|EL . From the thermodynamic calculation, we find that the higher µO2 FE|EL , the greater the Gibbs free energy. The change of Gibbs free energy of two possible carbon deposition reactions: CO electroreduction reaction and Boudouard reaction, are compared. Gibbs free energy changes of CO reduction reaction are evaluated based on different RSOC cell parameters as well as operating conditions, including cell voltage, current density, electrolyte thickness, electronic and ionic conductivity of electrolyte and electrodes interfaces. In this research we found that: CO can still be electrochemically reduced even the Boudouard reaction is absent in the fuel electrode. Therefore, suppressing CO electrochemical reduction reaction is critical to eliminate carbon deposition in RSOC.The RSOC is prone to carbon deposition under high cell voltages . Therefore, carbon deposition tends to occur in electrolysis mode rather than in fuel cells mode when CO concentration and cell parameters are the same. High CO concentration in the fuel mixture also facilitates carbon deposition.A thin electrolyte layer significantly increases oxygen chemical potential µO2 FE|EL at the interface of fuel electrode and electrolyte thus fabricating thin electrolyte is critical for eliminating carbon deposition. What is more, carbon deposition can be suppressed with an electrolyte exhibiting a high electronic conductivity σe EL and/or a low low ionic conductivity σi EL , indicating that increasing σe EL by doping elements such as Ce into YSZ electrolyte can help prevent carbon deposition.Modifying the interfacial area specific electronic resistance re FE|EL and ionic resistance ri FE|EL across fuel electrode and electrolyte also contribute to carbon deposition prevention. Increasing re FE|EL or reducing ri FE|EL is beneficial to suppress carbon deposition.Contrary to the the interface between fuel electrode and electrolyte, low interfacial area specific electronic resistance re OE|EL and high interfacial area specific ionic resistance ri OE|EL is in favor of suppressing carbon deposition. However, a relatively lower ri OE|EL is also required to obtain an outstanding RSOC electrochemical performance.

Effects of Aromatic Surfactants on Tin Electrodeposition

As the technology of quantum computing continues to develop, the necessity of finding materials that can be used to integrate the superconducting 3D architecture becomes more essential1. The electrodeposition of metals demonstrates an attainable way to manufacture vertical superconducting interconnects. In particular, Sn is one of the promising candidates to use because of its relatively high superconducting transition temperature (Tc) at 3.7 K, as well as its excellent manufacturability and self-passivation2. To ensure a void-free filling of the via like structure, organic additives that can function as suppressors, accelerators, or levelers will be needed to tune the deposition rate in the structure. While multi-additive systems have been used to control the deposition and the fabrication of conventional Cu interconnect structures, in other cases it has been demonstrated that a single additive can also enable the filling of Cu vias by suppressing the deposition at a certain range of potentials with a breakdown of the suppression occurring at another range3-4. Because of the importance of suppressive additives used in superconformal deposition, this work looks to explore the relationship between the degree of aromaticity and the level of suppression in additive assisted electrochemical deposition of Sn. Organic surfactant molecules including Igepal CO 520 and ethoxylated α-napthalenesulfonic acid (ENSA-6) are used for the comparative study in acidic stannous sulfate electrolytes.The effects of the additives on the deposition are studied using cyclic voltammetry and chronoamperometric measurements. Both Igepal and ENSA-6 were able to suppress the deposition of tin while additives with similar molecular weight but no aromatic rings appear to have little impact. Furthermore, the suppression increases with concentrations of the additives, with varying degrees of aromaticity showing a slight difference in suppression strength. Finally, the adsorption and desorption of the additives as well as the deposition transients are studied by varying voltage sweep rate and electrode agitation, the results will be discussed in details. References Yanay, Y., Braumüller, J., Gustavsson, S., Oliver, W. D., & Tahan, C. (2020). Two-dimensional hard core Bose–Hubbard model with superconducting qubits. Npj Quantum Information, 6(1).Huang, Q. (2023). Superconductivity of electrodeposited Sn films. Journal of The Electrochemical Society, 170(3), 032506.Radisic, A., Lühn, O., Philipsen, H. G. G., El-Mekki, Z., Honore, M., Rodet, S., Armini, S., Drijbooms, C., Bender, H., & Ruythooren, W. (2011). Copper plating for 3D interconnects. Microelectronic Engineering, 88(5), 701–704.Moffat, T. P., & Josell, D. (2012a). Extreme bottom-up superfilling of through-silicon-vias by damascene processing: Suppressor disruption, positive feedback and Turing patterns. Journal of The Electrochemical Society, 159(4).

Hybrid Polymer-Liquid Electrolytes and Their Interfaces Towards Electrode Materials for Lithium Ion Batteries

The escalating demand for efficient, safe, and sustainable energy storage solutions has highlighted lithium-ion batteries (LIBs) as pivotal in the transition towards renewable energy and electrification of society. Despite their widespread adoption, driven by superior energy density, longevity, and low self-discharge rates, LIBs present challenges concerning safety, cost, and environmental impact. The liquid electrolytes traditionally used in LIBs show safety hazards due to their flammability and potential for leakage which impede the utilization of high-voltage cathode materials, thus limiting overall battery performance and reliability.This study focuses on the exploration and implementation of hybrid polymer-liquid electrolytes (HEs) as a novel approach to circumvent these challenges. HEs, characterized by their unique combination of solid and liquid phases, aim to leverage the benefits of both electrolyte types to enhance safety while maintaining good thermal stability and ionic conductivity. Particularly, the research is focused on the process known as polymerization-induced phase separation (PIPS) consisting in the synthesis of HEs with distinct phase-separated systems, where a liquid ion-conducting phase percolates the macropores and mesopores of the formed thermoset encapsulating phase. The electrochemical performance of such a system depends on the chemical interaction between the liquid and the polymer phase and on the nm-scale morphology of the structure [1]. In this context, the pivotal role of interfaces within LIBs is analyzed, with an emphasis on the electrochemical processes at electrode-electrolyte interfaces that are crucial for the operational efficiency and lifespan of batteries. The study investigates commercial cathode materials highlighting their respective merits and challenges in relation to HEs. The primary objective of this investigation is to evaluate the feasibility of infusing cathode materials and to show that PIPS is possible within both micron-sized and nano-sized confined spaces. By incorporating these HE-infused electrodes into half-cell configurations, the study aims to prove their compatibility with high voltage electrode materials exhibiting energy density and battery performance comparable with traditional systems. A significant focus is placed on assessing the morphological and electrochemical stability of HEs after cycling, validating their practicality and effectiveness in enhancing battery safety while preserving efficiency.This research endeavors to push the boundaries of current battery technology, proposing innovative solutions to longstanding challenges. By exploring the synergistic effects of HEs with a broader selection of cathode materials, the study aims to contribute valuable insights towards the development of safer, more efficient, and environmentally friendly LIBs. Acknowledgements The Swedish Energy Agency (grant #48488) is gratefully acknowledged for financial support.

Effects of the passive voltage divider in a photomultiplier tube: Analytical model, simulations and experimental validation

The effects of the passive resistive voltage divider network in a photomultiplier tube (PMT) have been investigated by developing an in-house Monte Carlo simulation code and compared with experimental measurements and an analytical model. The simulation code follows an iterative procedure that takes into account the transport and amplification of the electrons within the device depending on the electrostatic fields produced by the electrode voltages. The PMT gain, dynode voltages, rise time and transit time have been studied as a function of the photocathode current and supply voltage. A good agreement between the analytical model, the simulations and numerous experimental measurements using a Hamamatsu R13408-100 PMT has been obtained. The simulation results endorse the use of logistic functions within the analytical model to account for the collection efficiency in the last dynode stages. This works deepens the understanding of passive voltage dividers and develops an advanced behavioral circuit model of photomultiplier tubes. Although validated for a single PMT, the proposed methodology is applicable to any PMT model. This aids in optimizing the design of fully active voltage dividers, to be applied in extremely pulsed applications with high count rates such as prompt gamma-ray imaging during proton therapy.

Optimization of hydrogen production via electrocatalysis using NiCoMo-modified electrodes: An RSM approach

ABSTRACT The depletion of fossil fuels and the environmental impact of their combustion have increased the demand for sustainable energy alternatives, with hydrogen appearing as an appropriate option due to its clean energy potential. This study focuses on developing a laboratory-scale alkaline electrolysis system for hydrogen production. Platinum, known for its high catalytic activity and durability, was employed as the anode, while graphite was selected as the cathode for its cost-effectiveness. To enhance catalytic performance, the graphite electrodes were modified with nickel-cobalt-molybdenum (NiCoMo) using a galvanostatic method. The electrode voltage and molarity were chosen as independent variables to evaluate their effect on hydrogen production. Using the Design-Expert software, the optimal conditions were identified at 3 V and 1.5 mol/l, yielding 10.67 ml of hydrogen. The coefficient of determination (R2) values 98.81% for R2, 97.96% for adjusted R2, and 91.63% for predicted R2 indicate suitable model accuracy. The error margin between experimental and optimized results was only 1.7%, confirming the reliability of the method. This study highlights the potential of NiCoMo-modified electrodes to enhance hydrogen production efficiency. Future research could explore scaling up the system and integrating it with renewable energy sources, positioning this method as a viable pathway toward sustainable hydrogen production.

Mutual effects between a gliding arc discharge and a premixed flame

Mutual effects between a gliding arc (GA) discharge at atmospheric pressure and a premixed CH4/air flame were experimentally investigated. Effects of the flame on the GA were studied using simultaneous measurements of the current, the voltage, and the instantaneous images of the plasma columns. The GA in the flame has a thicker and more diffusive plasma column, and it is more frequently ignited at a smaller breakdown voltage than that in the air. The GA extension velocity and the gliding velocity in the flame are larger than those in the air. The electrode voltage drop of the GA discharge in the flame is about 160 V, whereas that in the air is about 220 V. Compared with the GA in the air, the different features of the GA in the flame can be explained by high-temperature, weakly ionized, and species-abundant environment that are generated by the premixed CH4/air flame. Effects of the gliding arc discharge on the premixed flames were demonstrated using planar laser-induced fluorescence of hydroxyl radicals (OH) and formaldehyde (CH2O). OH and CH2O can be formed in the CH4/air mixture in the presence of the GA due to kinetic effects, and the increase of OH and CH2O shows the great potential of the GA for combustion enhancement.

Investigating the Impact of Varied C-Rates on Lithium-Ion Batteries: A 1D Simulation Study

Abstract With the advancement of powertrain technology and progressive vehicle electrification, one of the solutions for the growing need for energy storage is batteries. A secondary battery is a device that stores electrical energy in chemical form and delivers it as electrical energy when needed (discharging), with the possibility to revert the process converting electrical to chemical energy (charging). The lithium-ion battery type used in the study offers increased energy and power density with a cell voltage of approximately 3.6 V, making it suitable for use in portable electronic devices like mobile phones and laptops. In this research, a 1D model (through-electrolyte direction) of lithium-ion battery was analysed, in which the effect of different C-rates was investigated using the battery and design module of COMSOL Multiphysics software for 0.1C, 0.5C, 1C, 2C, and 3C rates, relevant for automotive applications. The simulation results of the lithium-ion battery model constitute an important step towards the development of battery technology, allowing an understanding of the transport processes in the electrodes and electrolyte. The results revealed that under higher C-rates of operation, differences emerge in electrolyte and electrode voltage ranges, salt concentration profiles in the electrolyte, surface and center electrode particle lithium concentrations.

Development of hydrogen ionic plasma source with superimposed positive-ion beam

A hydrogen ionic plasma source has been developed that is with a low residual electron presence (<0.01) using an aluminum plasma grid for negative hydrogen ion production and a control grid for electron removal. The ionic plasma density increases when a positive-ion beam is superimposed on a hydrogen plasma and irradiated onto the Al plasma grid. Even though the ionic plasma is formed in a region with high-deflection magnetic flux density, a collapse phenomenon can occur downstream of the region under certain electrode voltage conditions, causing electrons to appear and forming an electron plasma. Under electrode voltage conditions that prevent the collapse, the nine ionic plasmas, each passing through extraction apertures with a diameter of 1.3 cm, are combined to form the ionic plasma with a diameter of approximately 6 cm and a density on the order of 109 cm−3.

A Review On Multi objective Optimisation of Process Parameters in Shielded Metal Arc Welding For Joining Stainless Steel 3041 And Mild Steel 1018

Due to Mechanical properties of the welding metal and heat affected zone (HAZ) is quality of welding in this research work the review of Multi-objective optimization of welding process parameters for obtaining best weld strength with good mechanical properties of dissimilar metals like stainless steel 3041 and Mild steel 1018 is done. This process used for welding is shielded Metal Arc welding and dissimilar metal are stainless steel 3041 and mild steel 1018. Welding speed, depend on electric property like current Voltage electrode angle, feed rate, Arc length are taken as controlling variables. The weld strength (N/mm2) and Bead geometry variables and Heat Affected Zone are obtained by set of experiment, the possible best outcomes and best method has been chosen by this research. Keywords: HAZ, Multi objective optimization, Response surface Methodology, Shielded metal arc welding

Research on a miniature Mattauch-Herzog mass spectrometer designed for space exploration

Mass spectrometers have gained increasing importance in recent space missions. This paper presents the development of a miniature Mattauch-Herzog mass spectrometer for mass analysis. The mass spectrometer consists of an electron ionization (EI) source, an electrostatic and magnetic mass analyzer, and a focal plane detector. The construction of the EI source is based on a study of the impact of electrode voltages on ion focusing performance and ion transmission efficiency using the phase space method in the SIMION-8.1 software. The SIMION model of the mass analyzer is utilized to analyze the effects of electrostatic field voltage and magnetic fringe field on the ion beam. Experimental results from the instrument prototype demonstrate that the ion beam is influenced by the electrostatic field in a manner consistent with the simulation results of the SIMION model. The theoretical mass-to-charge ratio range of this double focusing mass spectrometer (DFMS) is 8amu–300amu, and it is capable of distinguishing isotopes with mass differences larger than 0.3amu, such as Ne. The N2 peak width at Full Width Half Maximum (FWHM) is 0.4amu, the mass resolution is 70.0, and the minimum detectable pressure of N2 is 2.8 × 10−9Pa. The Xe peak width (FWHM) is 1.3amu, the mass resolution is 101.5, and the minimum detectable pressure of Xe is 4.4 × 10−9Pa.

Second harmonic generation induced by gate voltage oscillation in few layer MnBi2Te4

Nonlinear charge transport, such as nonreciprocal longitudinal resistance and nonlinear Hall effect, has attracted considerable interest in probing the symmetries and topological properties of new materials. Recent research has revealed significant nonreciprocal longitudinal resistance and nonlinear Hall effect in MnBi2Te4, an intrinsic magnetic topological insulator, induced by the quantum metric dipole. However, the inconsistent response with charge density and conflicting C3z symmetry requirement necessitate a thorough understanding of factors affecting the nonlinear transport measurement. This study uncovers an experimental factor leading to significant nonlinear transport signals in MnBi2Te4, attributed to gate voltage oscillation from the application of large alternating current. Additionally, a methodology is proposed to suppress this effect by individually grounding the voltage electrodes during second-harmonic measurements. The investigation underscores the critical importance of assessing gate voltage oscillation’s impact before determining the intrinsic nature of nonlinear transport in 2D material devices with an electrically connected operative gate electrode.

Electrode length effects on the performance of the electrostatic quadrupole triplet lens

The present work aims to better understand the relationship between the electrode length of the electrostatic quadrupole triplet lens (EQTL) and its optical properties, as well as the possibility of increasing efficiency by selecting the electrode length that produces the best results, as this topic has not been discussed in previous studies. The effects of electrode length on the performance of the quadrupole triplet lens (QTL) were studied. The quadrupole triplet lens (QTL) electrode voltage combinations were found to produce the stigmatic image, and the effects of electrode length on the image’s characteristics were examined. Two lenses with electrode lengths L of 80 mm and 90 mm were designed, and the comparisons were made to show the effects on the electrode voltages, electron beam trajectories, and aberration figures. The findings indicated that a 12.5% increase in electrode length resulted in a 60% increase in aberration figures for Δy in point object-to-point image focusing mode and an 80% increase for Δz in parallel object-to-point image focusing mode.

Production and research of tungsten carbide powder from VA grade tungsten metal waste in aviation kerosene

Purpose. Obtaining and studying the composition, structure and properties of tungsten carbide powder from VA grade tungsten metal waste in aviation kerosene. Methods. Tungsten carbide powder from tungsten metal waste of the VA brand was obtained in the following sequence. The reactor was filled with a working medium – aviation kerosene of the TS-1 brand, the waste was loaded into the reactor. Electrodes were mounted from the same waste tungsten of the VA brand. The mounted electrodes were connected to a pulse generator. The necessary electrical parameters of the installation were set: the capacitance of the condensers is 42.0–43.5 UF; the voltage on the electrodes is from 115–120 V; the pulse repetition rate is 50–55 Hz. The resulting tungsten powder was studied using: a scanning electron microscope QUANTA 600 FEG; a particle size analyzer Analysette 22 NanoTec; an energy-dispersed X-ray analyzer from the company EDAX; X-ray diffraction on a diffractometer Rigaku Ultima IV. Results. Based on the conducted experimental studies, a new method for producing tungsten carbide powder has been developed, characterized in that the powder is obtained by electroerosive dispersion of tungsten metal waste of the VA brand in aviation kerosene at a capacitor capacity of 42.0–43.5 UF, an electrode voltage of 115–120 V and a pulse repetition frequency of 50–55 Hz. It has been experimentally established that spherical and elliptical particles of tungsten carbide powder W2C have sizes from 2.26 microns to 90.72 microns with an average volumetric diameter of 20.2 microns and contain carbon on the surface. Conclusion. The production of tungsten carbide suitable for industrial use at low energy costs from metal waste has shown high efficiency of the technology of electroerosion dispersion.