Electrode Spacing Research Articles

Comparison of electrically evoked stapedial reflexes in patients with cochlear implants surgically implanted using Veria and posterior tympanotomy approaches.

The study aimed to compare ipsilateral and contralateral electrically evoked stapedial reflex thresholds in children with a unilateral cochlear implant surgically implanted either through Veria or posterior tympanotomy approaches. Forty-nine children using cochlear implants were studied, of whom 27 underwent the Veria approach and 22 underwent the posterior tympanotomy approach. The electrically evoked stapedius reflex thresholds were measured ipsilaterally and contralaterally by stimulating four equally spaced electrodes. The ipsilateral electrically evoked stapedius reflex threshold was absent in all four electrodes in the children implanted using the Veria approach. However, the ipsilateral electrically evoked stapedius reflex threshold was present in 70 per cent of the children implanted using the posterior tympanotomy approach. The contralateral electrically evoked stapedius reflex threshold was present in most of the children for both surgical approaches. The presence of the ipsilateral electrically evoked stapedius reflex threshold varies depending on the surgical technique used for cochlear implantation. However, contralateral reflexes are present in the majority of children using cochlear implants, irrespective of the surgical approach.

Effect of high voltage discharge on germination characteristics of vetch seeds at high altitude

High-voltage electrostatic fields and low-temperature plasma technology at atmospheric pressure have an important impact on biological growth promotion. Therefore, a multi-needle-column-plate corona plasma generator is proposed in this paper. The negative corona voltammetry characteristics of multi-needle-plate electrodes and multi-needle-column-plate electrodes with different electrode spacing are investigated experimentally, and the electric field distribution of the device is simulated. The device was also applied to vetch seeds at high altitudes to investigate the effect of discharge on germination and root length. The results show that the introduction of column electrodes can effectively improve the electric field distribution of the device so that the device can provide two modes of high voltage electrostatic field and corona plasma field, and ensure the uniform treatment of seeds when the electrode spacing is 3 cm. The treatment of this device accelerates seed germination and promotes root growth, and is more effective under the combined influence of higher electric field strength, ionic wind generated by the discharge, and the active species than a single factor with a lower electric field, as well as shortening the duration of action. The high voltage electrostatic fields at −3 kV, −6 kV, and −9 kV and the corona discharge plasma fields at −12 kV, −15 kV, and −18 kV can effectively accelerate the germination of vetch seeds as well as promote the root growth under the treatment time of 10 min, 20 min, and 30 min. The optimal conditions were −9 kV for 30 min and −15 kV for 10 min, respectively.

Fabrication and photonic applications of Si-integrated LiNbO3 and BaTiO3 ferroelectric thin films

Silicon, renowned for its applications in electronic circuits, also offers significant advantages in the realm of integrated optics. While silicon does have inherent limitations in fabricating active devices, these challenges can be overcome through heterogeneous integration with other materials. Ferroelectric materials like lithium niobate (LN) and barium titanate (BTO) exhibit exceptional electrical and nonlinear optical properties, making them ideal candidates for integrated silicon photonics. Over the past few decades, the LN platform has made substantial progress, surmounting obstacles such as manufacturing difficulties, high waveguide losses, and low modulation bandwidth caused by wide electrode spacing. Consequently, LN-based devices have found widespread application in various fields. With the advent of high-quality, large-size LN on insulator wafers, LN photonics has become a burgeoning research area. At the same time, the ferroelectric material BTO, with its tremendous electro-optic response, shows promise for the next generation of integrated photonics. Recent studies have highlighted the remarkable performance of BTO-based modulators, which offer smaller device sizes compared to LN by achieving lower half-wave voltages. This comprehensive review presents various fabrication methods for integrating LN and BTO thin films on silicon, focusing on recent advancements. We discuss their electro-optic responses and provide an overview of the diverse applications enabled by these platforms. Finally, we summarize the current state of integrated LN and BTO photonics research and offer insights into future directions.

Microwave Optical Switches Metal–Semiconductor–Metal Schottky based on GaAs

Interdigitated metal–semiconductor–metal (MSM) photodetectors have received considerable attention for applications in microwave optical phoswitches. The impulse response of photoswich interdigitated fabricated metal-semiconductor- on GaAs metal non-intentional doped (NID) absorbing layer is investigated. The photodetector MSM is introduced in the microwave lines have active surfaces of 3x3 m2 and electrode spacing of 0.2, 0.3, 0.5 and 1 m.. The photocurrent response was measured after excitation and we found that the screening of the dark electric field and charge accumulation exceedingly modify the drift conditions of the photogenerated electrons and holes in active region of the MSM photoswich.

Research on Metal and Living Foreign Object Detection Method for Electric Vehicle Wireless Charging System

In the electric vehicle wireless power transmission system, the high-frequency alternating magnetic field between the transmitter and receiver can have a certain impact on the health of living organisms and may even lead to lesions. In addition, metal foreign objects in an alternating magnetic field can cause their own heating or even cause fires due to the eddy current effect, so foreign object detection is an essential function in the wireless power transmission system of electric vehicles. In order to prevent metals and living organisms from entering the charging area and causing harm to the charging system and living organisms, this paper proposes a method for detecting living organisms and metal foreign objects. Firstly, the equivalent circuits for the detection systems of the living organism foreign objects and metal foreign objects are established, respectively, and the working theory of the detection system is analyzed by deriving equations. Secondly, the comb capacitor simulation model was constructed, and the comb capacitor electrode spacing, wire thickness, and capacitor spacing were designed based on the scale factor γ to explore the effects of the height and bottom area of the living organism’s foreign object on the comb capacitor. We constructed a simulation model of the detection coil and designed the inner diameter D, the number of turns N, and the wire spacing S of the detection coil according to the scale factor β. An arrayed detection coil and comb capacitor combination mode is proposed to realize the function of the simultaneous detection of metal and living organism foreign objects, and a compensation capacitor is introduced to keep the detection system in a resonant state. Lastly, a platform for foreign object detection experiments was set up to detect metal screws and beef chunks compared to the detection area without foreign objects. Metal screws entering the detection area cause a 20% voltage drop in the detection circuit resistor, and beef chunks entering the detection area cause a 30% voltage drop in the detection circuit resistor, so the detection method is effective in detecting both metals and living organisms. The feasibility of the combined mode of arrayed detection coils and comb capacitors was verified.

Influence of optical grating on the triggering efficiency of VCSI silicon carbide photoconductive semiconductor switch

In this article, we present a new configuration of opposed-contact vanadium-compensation semi-insulating (VCSI) 4H–SiC photoconductive semiconductor switch (PCSS) to reduce the input laser energy for operation. The configuration is made up of three parts: the PCSS with optical grating, the convex lens in front of PCSS, and the additional reflector behind PCSS. Periodic surface structures were fabricated on the VCSI 4H–SiC substrate by ultrafine femtosecond laser direct writing to etch optical gratings. The microstructure on the lower surface plays the role of reflection grating, so that the laser forms a specific distribution pattern and enhances the laser absorption. Experiments and simulations show that the triggering efficiency increased 3.7 times compared to PCSS without grating at 532 nm laser. And output voltage can reach 90 % of the input bias voltage. This SiC PCSS optical system significantly reduces the laser energy without reducing the electrodes spacing.

Characterizing air-coupled gas discharge acoustic transducers by using scanning laser Doppler refracto-vibrometry

Scanning laser Doppler vibrometry (SLDV) is an effective tool for characterizing acoustic transducers and visualizing acoustic waves, in particular, when using air-coupled ultrasonic emitters. Refraction of laser beams in the areas of oscillating air pressure enables measuring amplitude-frequency parameters of propagating waves in a wide range of frequencies. The technique of refracto-vibrometry has been used for non-contact measurement of phase and frequency parameters of vibration signals generated by a pulsed gas discharge in the ambient air. The proposed gas discharge acoustic transducer operates on the base of the electro-thermoacoustic effect accompanying the flow of spark discharge current in the air at atmospheric pressure. A feature of the proposed device is that the emitter membrane contains a central through-hole that allows the discharge plasma to propagate beyond the electrode space of the emitter. Such configuration of the emitter allows the generation of acoustic waves in the ultra-wide frequency range from 50 Hz to 4 MHz. The spectrum of generated oscillations is essentially non-uniform that is explained by the presence of both resonance peaks and absorption bands of acoustic waves in the device elements. The proposed technique was checked in the inspection of impact damage in a hybride CFRP/flax composite.

Effect of Interlayer Spaces and Interfacial Structures on High-Performance MXene/Ionic Liquid Supercapacitors: A Molecular Dynamics Simulation.

The combination of high-capacitance MXenes and wide-electrochemical-window ionic liquids (ILs) has exhibited bright prospects in supercapacitors. Several strategies, such as surficial functionalization and interlayer spacing tuning, have been used to enhance the electrochemical performance of supercapacitors. However, the lack of theoretical guidance on these strategies, including the effects of the microenvironment in the interlayer of confined ILs, hindered the further exploration of such devices. Herein, we performed molecular dynamics simulations to comprehensively investigate the effects of the interlayer space and surface terminations of MXene electrodes on capacity. The results show that the electrical double layer (EDL) structure was found to form on the interface between the MXene electrode and ILs electrolyte by analyzing the ion number density and charge density in the nanometer confined spaces. Under the same potential, the -OH terminations significantly impact the ion orientation in the EDL, particularly near the electrode surface, where cations tend to align vertically, allowing the retention of more cations at the electrode surfaces. Interestingly, such an orientation distribution was decisively from the hydrogen bonds expressed by O-H···O between the -OH termination of MXene and -OH groups of ILs. The differential capacitances of the supercapacitors were calculated by the surficial electron density, and it showed that the capacitance is a nearly one-quarter increase in the 14 Å interlayer spacing compared with that of 10 Å under an applied potential of 2 V. At the same time, the Ti3C2(OH)2 electrode had a higher differential capacitance than the Ti3C2O2 electrode, which possibly originates from the stronger hydrogen bonds to contribute to the vertical aggregation of the cations. Our results highlighted the roles of the interlayer spacing distance and surface terminations of the MXene on the performance of the type of supercapacitor.

Mitigation of fouling problem and optimization of treatment effect in the polyvinylidene fluoride (PVDF) based electrochemical membrane bioreactor (EMBR)

The hydrophobic polyvinylidene fluoride (PVDF) membrane is one of the most widely used membrane material in the treatment of domestic sewage, while it still endures the fouling problem. Many studies have focused on the fouling control, among which the electrochemical membrane bioreactor (EMBR) is promising because of its chemical-free nature, but the specific influence of applied electric field on the mitigation of membrane fouling and the treatment effect are unclear and need further exploration. In this work, the influence and interaction of operation parameters (operation voltage, electrode spacing, power-on mode, and hydraulic retention time) on fouling development and pollutants removals in a PVDF based EMBR were carefully explored for the optimal operating conditions. Results showed that the run time of EMBR system under optimal conditions was 23.4 % longer than that of the MBR system without a weak electric field, indicating that the membrane fouling problem was well alleviated. In addition, the effluent quality of EMBR was also improved than that treated by the MBR system. The removal rates of chemical oxygen demand, ammonia nitrogen, total phosphorus, and total nitrogen were increased by 2.25 %, 2.64 %, 9.02 %, and 12.1 %, respectively, revealing the improvement of this EMBR system in sewage treatment. This work shows that introduction of a weak electric field in MBR system not only effectively controls membrane fouling, but also increases the effluent quality, and thus endows EMBR as a candidate for sustainable and green technique in sewage treatment.

High-density mapping of Koch's triangle during sinus rhythm and typical atrioventricular nodal re-entrant tachycardia, integrated with direct recording of atrio-ventricular node structure potential.

The mechanism of typical slow-fast atrioventricular nodal re-entrant tachycardia (AVNRT) and its anatomical and electrophysiological circuit inside the right atrium (RA) and Koch's Triangle (KT) are not well known. To identify the potentials of the compact AV node and inferior extensions and to perform accurate mapping of the RA and KT in sinus rhythm (SR) and during AVNRT, to define the tachycardia circuit. Consecutive patients with typical AVNRT were enrolled in 12 Italian centers and underwent mapping and ablation by means of a basket catheter with small electrode spacing for ultrahigh-density mapping and a modified signal-filtering toolset to record the potentials of the AV nodal structures. Forty-five consecutive cases of successful ablation of typical slow-fast AVNRT were included. The mean SR cycle length (CL) was 784.1 ± 6 ms and the mean tachycardia CL was 361.2 ± 54 ms. The AV node potential had a significantly shorter duration and higher amplitude in sinus rhythm than during tachycardia (60 ± 40 ms vs. 160 ± 40 ms, p < .001 and 0.3 ± 0.2 mV vs. 0.09 ± 0.12 mV, p < .001, respectively). The nodal potential duration extension was 169.4 ± 31 ms, resulting in a time-window coverage of 47.6 ± 9%. The recording of AV nodal structure potentials enabled us to obtain 100% coverage of the tachycardia CL during slow-fast AVNRT. Detailed recording of the potentials of nodal structures is possible by means of multipolar catheters for ultrahigh-density mapping, allowing 100% of the AVNRT CL to be covered. These results also have clinical implications for the ablation of right-septal and para-septal arrhythmias.

GHz surface waves in Al/LiTaO3/Si composite: Effect of the Drude electrode on dispersion, attenuation and mode shapes

In fifth generation (5G) mobile communication, radio frequency is in the super high frequency range (3–30 GHz). Thus, different from Ohm law, electrode loss at GHz frequency becomes frequency-dependent. As such, many properties, especially attenuation of piezoelectric acoustic devices, should be reevaluated. In this paper, the attenuation of GHz surface wave propagating in composite structure made of metal electrode, piezoelectric film and elastic half space is investigated based on the loss model of Drude electrode. Specifically, the Al/LiTaO3/Si composite is considered where Rayleigh mode and SH mode are fully coupled. Based on the Stroh-type formalism, the dispersion equations of the composite with the Drude electrode are derived, and compared with the traditional perfect conductor electrode which is under the short circuit boundary condition. The phase velocity, attenuation and wave mode shapes are obtained successfully by the multidimensional moduli ratio convergence method. Numerical results are presented to reveal some interesting intrinsic features, which include two analytical upper bounds of phase velocity, nonexistent validation of intersection points in dispersion curves, and relations among veering, attenuation jumps and wave-mode conversions. These features and relations provide an in-depth insight for GHz wave motion properties in piezoelectric composites.

Pemodelan 3D Bidang Gelincir Tanah Longsor Menggunakan Metode Geolistrik di Bukit Nobita Padang

The surface of rupture investigation has been conducted at Nobita Hill, Kampung Jua, Lubuk Begalung, Padang City using the 3-dimensional resistivity geoelectric method in Wenner configuration. The research was conducted in a hilly area with a slope of up to 40º. Data was collected on three tracks with variations in length lengths of 120 and 240 m. The electrode spacing is 6, 12, 18, and 24 m for current and potential electrodes. Data processing was carried out using Res2dinv software to display a 2-dimensional image of the subsurface layer based on the resistivity values measured in the field. The results of 2-dimensional image processing were then modeled in 3 dimensions using Voxler software. Data interpretation of the results obtained by Track 1 has a resistivity value of 1170-2028 Ωm at a depth of 4.5-19.1m. Track 2 has a resistivity value of 1052-1768 Ωm with a depth of 4.5-19.1 m. Track 3 has a resistivity value of 1492-2937 Ωm at a depth of 1.5-19.1 m. The direction of the sliding plane of Tracks 1 and 2 is to the northwest, while track 3 is to the northeast. The results showed that the sliding plane on each track is granite.

Study on Optimization of MFC Electric Generation Parameters based on Box-Behnken Design

MFC is a new energy technology that has emerged in the fields of environmental protection and energy. MFC has achieved the function of clean pollution and electricity generation, maximizing the environmental protection needs of the current shipping industry. However, MFC has the disadvantages of low power generation, unstable operation and high cost, which restrict its engineering application. This article uses single factor analysis and Box- Behnken experimental design to explore the output voltage of MFC under different levels of power generation parameters. Through variance analysis, the optimal power generation process parameters of MFC are determined to improve its power generation performance. The experimental results show that the order of significance of the parameters is temperature >pH> electrode spacing, the interaction between temperature and electrode spacing, pH and electrode spacing is the most significant, but the interaction between temperature and pH is not significant. Box-Behnken experimental model has good regression, and the optimal power generation parameters for MFC output voltage are: temperature of 29.85 °C, pH value of 6.96, and electrode spacing of 2.03 cm. Under this optimal power generation condition, the voltage predicted by the experimental model can reach 529.998 mV, while the voltage obtained by the actual experiment is 531.4 mV, and the error with the model prediction is only 0.26%, the data predicted by the Box Behnken response surface is reliable. The results show that the model can be well applied to the optimization design of MFC generating parameters.

Effects of different cathode conditions on electricity generation and removal of heavy metal pollutants in CW-MFC

The effect of treating copper-containing wastewater by CW-MFC technology was discussed. The power generation and wastewater purification efficiency of CW-MFC are affected by electrode spacing, cathode electrode area and influent copper concentration. Smaller electrode spacing may destroy the anaerobic environment in the wastewater, while larger electrode spacing will increase the total internal resistance of the system, resulting in a decrease in electricity generation efficiency. With the increase of cathode area, the removal efficiency of pollutants in wastewater will be improved. However, when the cathode area is too large, it will increases the internal resistance of the system, which will affect the electric production performance. When the best electrode spacing is 10 cm and the cathode electrode area is 75 cm2, CW-MFC shows the best power generation and wastewater purification effect. When the concentration of copper in the wastewater increases, the power generation and wastewater purification efficiency of the system will also increase. When the copper concentration reaches 50 mg/L, the system shows the best effect, its open circuit voltage reaches the maximum, and the removal rate of copper and total nitrogen is also the highest. When the concentration of copper in wastewater reaches 100 mg/L, the microbial activity is inhibited, resulting in a significant decline in the performance of CW-MFC.

Numerical simulation of flow field coupling with electric field for leakage current particulate matter sensor

With the diesel particulate filter more and more widely applied on engine, the particulate matter (PM) sensor is used to detect malfunctions of diesel particulate filter (DPF) in on board diagnostics (OBD). This paper focused on the new leakage current particulate matter sensor, which has more practical significance. The electric field and flow field were simulated by the COMSOL Multihysics, and the influence rules of sensor electrode parameters on the electric field and flow field were analyzed. The dynamic characteristics of particulate matters with different charges was studied. The simulation results showed that the average electric field strength was higher with higher electrode voltage and larger electrode spacing, which made the motion trend of charged particulate matter to electrodes more obvious. The decrease of electrode spacing or the increase of electrode length made the exhaust flow more stable, and the motion trend of charged particulate matters to electrodes is more obvious with the increase of electrode length. It was concluded that the flow of the exhaust and particulate matter was in good condition when the electrode spacing was 12.5mm, the electrode length is 12.5mm and the electrode voltage ranged between 1000V and 1500V.

Structural distortion-induced monoclinic sodium iron hexacyanoferrate as a high-performance electrode for rocking-chair desalination batteries.

Sodium iron hexacyanoferrate (NaFeHCF) has been recognized as a promising Prussian blue analogue (PBA)-based electrode for electrochemical desalination; however, its application potential is limited by its unsatisfactory desalination capacity and cycling stability. Herein, the structurally distorted high-quality monoclinic NaFeHCF with fewer defects in the framework was synthesized by a crystal-controlled coprecipitation method via tuning the crystallization reaction conditions and applied to seawater desalination. Physicochemical characterization and desalination experiments show that the NFHFC-2 with minimized defects possesses enhanced electrochemical activity of Fe2+ and electrochemical kinetics, thus achieving higher desalination performance (specific capacity of 75.0 mA h g-1 and capacity retention of 85.3% after 50 cycles). Furthermore, a symmetrical NFHCF-2 RCDB is assembled, and the operation parameters (including various salinities and electrode spacing) are optimized to achieve a remarkable salt removal capacity (SRC) of 108.9 mg g-1 and a salt removal rate (SRR) of 2.22 mg g-1 min-1 with low energy consumption (0.056 kW h kg-1-NaCl) and outstanding cycling stability (almost no capacity attenuation in 150 cycles). Impressively, the RCDB further exhibits favorable technical feasibility in the simultaneous removal of univalent/bivalent ions from the natural seawater. This study inspires the design of high-quality PBA-based electrodes with optimized crystal structures for electrochemical desalination.

The Application of Three-Dimensional High-Density Electrical Method in Detecting Vertical HDPE Membranes at Landfill Sites

Landfilling is one of the important methods in hazardous waste treatment. In order to prevent the landfill leachate from connecting with external groundwater and prevent leachate from flowing into external polluted water bodies and soil, vertical anti-seepage membranes will be installed along the perimeter of the reservoir area. Given the structural characteristics of vertical HDPE membranes and site conditions, this study proposes the application of three-dimensional high-density electrical resistivity (3D-HDER) tomography for the detection of these membranes. Compared with the traditional resistivity method, the high-density resistivity method can realize automatic switching of electrode device type, electrode spacing and measuring points during the measurement process, thereby improving detection accuracy and work efficiency. By employing 3D-HDER for data collection on vertical HDPE membranes and inverting the subsurface resistivity distribution, the presence of leaks can be inferred based on the distribution of low-resistivity anomalies in the target underground area, thereby facilitating the integrity assessment of the vertical HDPE membranes. This research was applied in a practical investigation at a municipal landfill site in Hunan Province, where field tests were conducted, and the effectiveness of 3D-HDER in detecting vertical HDPE membranes was validated through excavation. The experimental results indicate that: (1) 3DHDER is capable of effectively and accurately locating shallow leaks, and (2) low resistivity anomalies were observed in the vicinity of the leaks.

Optimization of Efficiency Mercury (Hg) Removal with Electrocoagulation Using Zinc (Zn) Electrode by RSM Methods

Good and optimal management of the Final Processing Site (TPA) can provide benefits to the community and the surrounding environment. One of the impacts of poor management of the landfill is that the decomposition of waste that occurs at the landfill will produce leachate which will potentially contaminate groundwater. Leachate from landfill can contaminate groundwater if it seeps into the ground and eventually into the groundwater. In one of the landfill’s in Medan City, namely Terjun landfill, it is known that the level of mercury (Hg) in leachate is 0.04012 which is categorized as exceeding the quality standard. Electrocoagulation is a promising treatment technology because it has the potential to remove organic matter and persistent pollutants in landfill leachate. The electrocoagulation process was carried out with variations of the electrocoagulation time used, namely 10, 20, and 30 minutes using zinc electrodes. As well as other variations used, namely the electrode spacing of 1 cm, 2 cm and 3 cm and the voltage of 8 volts, 10 volts and 12 volts. The results showed that the optimal variation was obtained at a distance of 2 cm, 30 minutes, and 12 volts with a mercury reduction efficiency of 98.108%.

Considerations on the Electrode-Spacing-to-Electrode-Diameter Ratio in Electrical Resistivity Tomography (ERT): An Operational Approach

Considerations on the Electrode-Spacing-to-Electrode-Diameter Ratio in Electrical Resistivity Tomography (ERT): An Operational Approach

Investigation of geometry-dependent sensing characteristics of microfluidic for single-cell 3D localization.

Flow cytometry-based measurement techniques have been widely used for single-cell characterizations, such as impedance, size, and dielectric properties. However, in the measurement process, the reliability of the output measurement signal directly affects the ability of the microsystem to judge the characteristics of single cells. Here, we designed a multiple nonparallel electrode structure for single-cell 3D localization. The performance of the structures was studied by analyzing the changes in electric field strength and the output differential current. The effects of microchannel height, sensing electrode distance, electrode inclination angle, and electrode width on output signals are investigated by analyzing the current change and electric field strength of single cells passing from the center of the microchannel. The numerical simulation results indicate that, when the microchannel height is 20 µm, the distance of the sensing electrodes is 100 µm, the inclination angle is 30°, the electrode width is 20 µm, and the optimal signal quality can be obtained. Reducing the height of the flow channel and shortening the sensing electrode spacing can significantly improve the signal amplitude. When the channel height is 20 µm, the signal intensity increases by 80% than that of 30 µm. The signal intensity of induced current with the sensing electrode spacing of 100 µm is 42% higher than that with the spacing of 120 µm. We analyzed the presence of multiple independent cells and adherent cells in the detection area and demonstrated through simulation that the signal changes caused by multi-cells can be superimposed by multiple single-cell signals. The induced current signal intensity of the same volume of cells with an ellipticity of 1 is 49% lower than that of cells with an ellipticity of 4. Based on the numerical investigation, we expect that the optimal geometry structure design will aid in the development of better performance signal cell impedance cytometry microsystems.