Short Electrode Research Articles

Enhanced Cochlear Coverage and Hearing Preservation in High-Frequency Hearing Loss via Electric Acoustic Stimulation with Longer Electrode.

Electric-acoustic stimulation (EAS) is a promising treatment to improve hearing ability in patients with high-frequency hearing loss (HL). In EAS surgeries, shorter electrodes have been preferred to avoid the presence of an electrode covering the residual hearing region. However, our earlier studies showed that EAS with longer electrodes (28 mm) could preserve acoustic hearing. Additionally, we reported that the hearing preservation (HP) scores were independent of the length of the inserted electrodes, consistent with the systematic review. As most EAS patients gradually lose residual hearing over time due to the natural course of HL, in these cases, providing broader cochlear coverage using longer electrodes was beneficial toward better place-pitch matching. In addition to preparing for the deterioration inhearing inthe future, EAS with longer electrodes could offer various types of map strategies. Herein, we show the pre-, intra-, and post-procedures for EAS surgery. Appropriate preoperative evaluation, less invasive surgery, flexible lateral-wall electrodes, and steroid administration resulted in good HP following EAS with longer electrodes.

Fuel transport mechanisms and power generation enhancement in air-breathing microfluidic fuel cells with discrete-hole anode

Current challenges in air-breathing microfluidic fuel cells (AMFCs) technology include insufficient fuel transfer and unsatisfactory power density. To address these issues, this study develops a three-dimensional computational model to optimize the performance of AMFC with a discrete-hole anode. This model reveals that the "petal-shaped" non-uniform fuel distribution is due to the shearing and dilution effects of the electrolyte. Additionally, discrete-hole structures such as size have a slight influence on fuel transport and current production, with performance deviations under 1.6%. Significant improvements are achieved by reducing the electrolyte flow rate and electrode length. Transitioning from a single cell with a long anode to a series/parallel stack of cells with short electrodes significantly boosts net power output and fuel utilization. Under optimal conditions, a maximum power density of 349.9 mW cm−3 and an output of 19.2 mW are obtained. This research provides valuable insights into fuel transport mechanisms and power enhancement strategies in the AMFCs, guiding the future design and optimization of microfluidic reactors for energy conversion.

Ultrasound-guided percutaneous radiofrequency ablation versus surgery for solitary T1N0M0 papillary thyroid carcinoma in the danger triangle.

To compare the safety and efficiency of ultrasound-guided percutaneous radiofrequency ablation (RFA) and surgical resection (SR) for thyroid papillary carcinoma (PTC) in the danger triangle area. The clinical data of 298 patients who underwent either percutaneous RFA or SR for PTC in the thyroid danger triangle at our hospital between January 2018 and April 2020 were retrospectively analyzed. Propensity score matching is employed to regulate for confounding factors. All patients undergoing ablation were treated using a strategy that combined sufficient paratracheal fluid isolation with a low-power, short electrode. Disease progression was analyzed in patients with T1N0M0 PTC (T1a and T1b) employed in Kaplan‒Meier curves. Treatment parameters and the rates of local recurrence, distant metastasis, and complications are recorded and compared. Of 182 eligible patients who were included, 91 were in the RFA (age 44.84 ± 13.19; 71 females; 77 T1a) and 91 were in the SR (age 47.36 ± 11.05; 68 females; 69 T1a). The average treatment time, length of hospital stays, blood loss volume, and scar length are substantially less in the RFA than in the SR. Major complications as well as postoperative permanent recurrent laryngeal nerve injury and postoperative transient parathyroid dysfunction occurred only in the SR, with a substantial distinction between the two groups (p < 0.05). There is no substantial distinction in the disease progression between RFA and SR treatment of T1N0M0 PTC. RFA is as effective as surgery for PTC in the danger triangle area in the short term, with faster recovery and fewer complications. Radiofrequency ablation has a clinical efficacy comparable to surgery in the treatment of papillary thyroid carcinoma in the danger triangle area in the short term with the advantages of faster recovery and fewer complications when compared with surgery. Use of radiofrequency ablation (RFA) in the thyroid danger triangle is still controversial. RFA and surgery groups showed no difference in disease progressions, and no major complications occurred with RFA. Radiofrequency ablation offers a new option for papillary thyroid carcinoma patients in the danger triangle.

Enhanced OER performance by varying Al-WO3 electrocatalyst thickness: Process optimization

Oxygen evolution reactions (OER) are highly significant and play a critical role in the advancement of fuel cells, electrolyzers, chemicals, and solar energy conversion devices. The challenge in the quest is attributed to the absence of an efficient electrocatalyst assembly that functions optimally. A simple method of electrodeposition of Al:WO3 on a fluorinated tin oxide (FTO) electrode was used to investigate the OER in this study. The electrodepositions were achieved by employing a three-electrode cell at various scan rates ranging from 10 to 100 mV/s. During this investigation, the influence of the scan rate on electrocatalyst loadings and the impact of electrocatalyst layer thickness on the OER were examined. The electrodepositions of Al:WO3@FTO were analyzed using a range of optical, chemical, and physical techniques such as SEM, XRD, FT-IR, Raman spectroscopy, EDX, EDS mapping, and electrochemical tests. The FTIR and Raman analysis confirmed the synthesis of AL:WO3 while the peaks detected at angles 38.7° and 43° by XRD with planes (111) and (200), served as a distinctive characteristic for identifying aluminum (Al). The peaks observed at angles of 27.8°, 30.7°, 33°, 50.45°, and 58° correspond to WO3 material. The characterization techniques also confirmed that the synthesized material is highly crystalline in nature. The OER potential using Al:WO3@FTO electrodes with different electrocatalyst thicknesses, ranging from 8 nm to 31 nm was investigated by studying various electrochemical techniques such as CV, LSV, CPE, Tafel slope, HP2P splitting, EIS, TOF, short and long-term electrode stability, and double layer capacitance. The linear regression coefficient (R2) was also calculated to measure the relationship between the electrocatalyst's thickness and each electrochemical test. The findings indicated that increasing the scan rates resulted in thinner and denser electrodepositions on the FTO substrate as the thinnest film was formed at 100 mV/s. An inverse relationship between electrocatalyst layer thickness and OER activity was observed. The electrode with the thinnest and most compact electrocatalyst layer, specifically ED Al:WO3@FTO08, exhibited the lowest onset potential of 1.48 V and a maximum current of 84 mA/cm2 at 1.76 V. It also demonstrated superior reaction kinetics, as evidenced by its lower Tafel slope value of 49 mV/dec, which is the lowest among all the electrodes that were prepared. In particular, the electrode with a thin and compact electrocatalyst layer worked better in OER operations than the other five electrodes that had higher amounts of Al:WO3.

Enhanced hydrogen peroxide electrosynthesis and prolonged lifespan by preparing gas diffusion electrode via electrodeposition of CB on Ni foam

In-situ hydrogen peroxide (H2O2) production is pivotal for the effective implementation of the electro-Fenton reaction. However, challenges such as low H2O2 yields and a short electrode lifespan have hindered its application. This study introduced a novel gas diffusion electrode (GDE), the CB(E)-Ni foam(GDE), fabricated through a combination of carbon black (CB) electrodeposition and polytetrafluoroethylene (PTFE) impregnation techniques. Comprehensive physicochemical characterizations and electrochemical evaluations indicated that CB was more uniformly dispersed across the Ni foam, enhancing its electrochemical activity. When employed as a cathode, the CB(E)-Ni foam(GDE) demonstrated superior two-electron oxygen reduction reaction (2e− ORR) capabilities, marked by increased oxygen utilization and reduced energy demands, achieving a remarkable H2O2 concentration of 897.73 mg/L after 120 min. This performance significantly outpaces that of traditional GDEs. The unique structure of the CB(E)-Ni foam(GDE) not only prolonged electrode life by preventing rapid deactivation but also boosted H2O2 production and oxygen efficiency by 31.78% and 31.79%, respectively, when compared to a standard non-GDE configuration. In practical applications, the CB(E)-Ni foam(GDE) demonstrated utility by facilitating an 84.1% degradation rate of fulvic acid over 120 min within a homogeneous electro-Fenton system, highlighting its potential for environmental remediation.

Lattice-dislocated bismuth nanowires formed by in-situ chemical etching on copper foam for enhanced electrocatalytic CO2 reduction

Electrochemical CO2 reduction reaction (CO2RR) to HCOOH is one of the most feasible and economical methods to achieve carbon neutrality. Bismuth (Bi), as a metal catalyst for CO2RR, is considered to have great potential for application and has been widely studied due to its high formate selectivity, low toxicity, cheapness, and abundance. Unfortunately, low current density and short electrode lifetime have hindered its progress towards practical applications. In this work, we present a method that enables the chemical etching of Bi on Cu, which is capable of spontaneously accomplishing the loading of Bi on Cu foam in the liquid phase at room temperature. Additionally, to provide more abundant catalytically active sites, twisted Bi nanowires (BiNWs) with lattice dislocations were successfully prepared on the surface of Cu foam using a three-step chemical method involving oxidation, reduction, and in-situ etching. The Cu Foam@BiNWs was found to be a highly active electrocatalyst for CO2 reduction to formate at a low applied potential, achieving a faradaic efficiency for formate (FEFormate) of 95 % and a formate partial current density of ∼ 12 mA cm−2 at −0.78 V vs. RHE (reversible hydrogen electrode). Even within such a wide potential window of −0.68 ∼ -1.08 V vs. RHE, the FEFormate is consistently above 90 %. Such exceptional CO2 reduction activity can be attributed to the distortions and lattice dislocations present in the surface BiNWs. Furthermore, the Cu Foam@BiNWs electrode demonstrated a total current density close to 100 mA cm−2 at −0.98 V in an alkaline flow cell, while maintaining excellent catalytic stability over a prolonged 30-hour period of high current density electrochemical activity, thus showing potential for advancing the industrialisation of formate production. This work emphasizes the crucial role of size-dependent catalysis and crystal defect engineering strategies in the field of electrocatalysis, elucidates the mechanism of the rate-determining step (RDS) in the electrocatalytic CO2 reduction process on the developed catalysts, which can provide valuable insights into the design and development of high performance electrocatalysts not only in CO2RR but also in other fields.

Electrode lifetime in resistance spot welding of coated sheets: Experiments and modeling

One of the most important challenges associated with resistance spot welding of coated sheets is short electrode life time. It has been established that the two factors-electrode tip growth and surface alloy formation-each affect negatively on electrode life when considered separately. This study's objectives were to examine the combined effects of these factors and ascertain how they relate to electrode life. Due to this, two electrodes were used to investigate the electrode life when resistance welding galvanized steel: a conventional Cu-Cr electrode with a compressive strength of 800 MPa and a dispersion strengthened copper electrode with a high volume percentage of alumina particles (3.5 %) with a compressive strength of 500 MPa. Electrode life time tests showed that the life of composite electrode (700 weld number) was reduced by about 20 % compared to Cu-Cr electrode (900 weld number). Electrode tip features showed that cracking in Cu-Cr electrode formed at about 200 weld number while in composite electrode this occurred at 600 weld number. The electrode tip cross section revealed the formation of four separate alloy layers at the tips of both electrodes, however the Cu-Cr electrode had significantly higher crack densities and a lower average thickness during life test (45 µm) than the composite electrode (55 µm). It was caused by the higher rate of electrode tip growth in Cu-Cr electrodes, which increased welding current and extended electrode life. A simple model was purposed for electrode life based on Joule heating effect that takes the effects of both electrode tip growth and electrode tip alloy formation in to account. According to the model and experiments when significant interaction occurs at the electrode tip, the some tip growth rate not only isn’t detrimental but also increases the electrode lifetime.

Increasing the rate capability for the cryogenic stopping cell of the FRS Ion Catcher

At the FRS Ion Catcher (FRS-IC), projectile and fission fragments are produced at relativistic energies, separated in-flight, energy-bunched, slowed down, and thermalized in the ultra-pure helium gas-filled cryogenic stopping cell (CSC). Thermalized nuclei are extracted from the CSC using a combination of DC and RF electric fields and gas flow. This CSC also serves as the prototype for the CSC of the Super-FRS, where exotic nuclei will be produced at unprecedented rates making it possible to go towards the extremes of the nuclear chart. Therefore, it is essential to efficiently extract thermalized exotic nuclei from the CSC under high beam rate conditions, in order to use the rare exotic nuclei, which come as cocktail beams. The dependence of the extraction efficiency on the intensity of the impinging beam into the CSC was studied with a primary beam of 238U and its fragments. Tests were done with two different versions of the DC electrode structure inside the cryogenic chamber, the standard 1 m long and a short 0.5 m long DC electrode systems. In contrast to the rate capability of 104 ions/s with the long DC electrode system, results show no extraction efficiency loss up to the rate of 2 × 105 ions/s with the new short DC electrode. This order of magnitude increase of the rate capability paves the way for new experiments at the FRS-IC, including studies of exotic nuclei with in-cell multi-nucleon transfer reactions. The results further validate the design concept of the CSC of the Super-FRS, which was developed to effectively manage beams of even higher intensities.

Comparing linear and non-linear models to estimate the appropriate cochlear implant electrode array length—are current methods precise enough?

PurposeIn cochlear implantation with flexible lateral wall electrode arrays, a cochlear coverage (CC) range between 70% and 80% is considered ideal for optimal speech perception. To achieve this CC, the cochlear implant (CI) electrode array has to be chosen according to the individual cochlear duct length (CDL). Here, we mathematically analyzed the suitability of different flexible lateral wall electrode array lengths covering between 70% and 80% of the CDL.MethodsIn a retrospective cross-sectional study preoperative high-resolution computed tomography (HRCT) from patients undergoing cochlear implantation was investigated. The CDL was estimated using an otosurgical planning software and the CI electrode array lengths covering 70–80% of the CDL was calculated using (i) linear and (ii) non-linear models.ResultsThe analysis of 120 HRCT data sets showed significantly different model-dependent CDL. Significant differences between the CC of 70% assessed from linear and non-linear models (mean difference: 2.5 mm, p < 0.001) and the CC of 80% assessed from linear and non-linear models (mean difference: 1.5 mm, p < 0.001) were found. In up to 25% of the patients none of the existing flexible lateral wall electrode arrays fit into this range. In 59 cases (49,2%) the models did not agree on the suitable electrode arrays.ConclusionsThe CC varies depending on the underlying CDL approximation, which critically influences electrode array choice. Based on the literature, we hypothesize that the non-linear method systematically overestimates the CC and may lead to rather too short electrode array choices. Future studies need to assess the accuracy of the individual mathematical models.

Acceleration of potential-induced degradation in crystalline Si photovoltaic modules after a lightning impulse strike

The potential-induced degradation (PID) is one of the significant issues in realizing low-cost electricity from photovoltaic (PV) power generation plants. In this paper, we have investigated PID in crystalline Si (c-Si) PV modules with conventional p-type multicrystalline Si solar cells after the application of lightning impulse strikes. Lightning impulses with a voltage of −40 kV were applied to the module between the shorted electrodes of the c-Si cell and the mimic aluminum frame. It is confirmed that no degradation in the electrical characteristics of the c-Si cell occurs by applying the impulse only. We have found that the PID of c-Si PV modules was accelerated by applying the impulses between a c-Si cell and a metal frame. The acceleration of PID in the module applied with a lightning impulse might be caused by the migration of Na+ ions easily toward the c-Si cell owing to damage to the ethylene-vinyl acetate encapsulant by impulses.

Corona Discharge Behaviors with Presence of Floating Electrode in Air Insulation using Numerical Model Analysis

This paper deals with numerical analysis method for analyzing the partial discharge behaviors in terms of corona discharge in the presence of a floating electrode under lightning impulse voltage. To analyze the corona discharge behaviors at 0.5 mm short electrode gap system as basic research work between main conductor and floating electrode, we considered fully coupled numerical model based on the charge continuity equations for positively charged ion, negatively charged ion and free electrons. Poisson’s equation is coupled with hydro-dynamic drift-diffusion equations derived from the three kinds of charge continuity equation. Fowler-Nordheim field emission is assumed that the electron emission by electric field is used as boundary conditions for main conductor and floating electrode. As a results, it is found that the floating electrode creates a non-uniform electric field distribution with a large field enhancement, causing ionization to initiate corona discharge. In other words, floating electrode is early corona discharge inception by collecting the induced charge developed by high voltage electrode. This result is expected to be applicable to various corona discharge generating systems as well as insulation design of power apparatus with presence defects such as a floating metal particle under lightning impulse voltage.

Coupling anodic and cathodic reactions using an electrocatalytic dual-membrane system actuates ultra-efficient degradation with regulable mechanisms

The versatile reaction possibilities arising from the interaction between the anodic and cathodic reactions naturally contained in electrocatalytic membrane filtration (EMF) systems are of great valuable in meeting the current complex water treatment requirements. But currently, most studies only focus on half-cell reactions with a single electrocatalytic membrane, which limits the research progress of the EMF technology. Here we report a coupling strategy that utilizes the interaction between the anodic and cathodic reactions to actuate ultra-efficient degradation performance with regulable reaction mechanisms. An electrocatalytic dual-membrane filtration (EDMF) system was established. Six typical configurations of the EDMF system were set up and systematically investigated by adjusting the electrode distance and filtration sequence. Based on the obtained results of degradation performance and mechanisms, a regulation strategy which enabled flexible tuning of direct nonradical oxidation (e.g., h+) and indirect oxidation (e.g., 1O2, ·OH, HO2·, O2·−, etc.) was proposed. In particular, cathodic reactions were found to adversely affect the anodic reactions at the relatively short electrode distance of 0.9 mm. Anodic reactions could inhibit the generation of 1O2 at short distance of 0.9 mm but promote its generation at long distances of 9 and 17 mm. The A–C_0.9 configuration achieved the highest degradation performance, while the C–A_9 configuration was revealed to be much more conducive to 1O2 production. Overall, our findings demonstrate the versatility and tunability of the reaction mechanism and performance of the EDMF system due to the flexible coupling of the anodic and cathodic reactions, which potentially lays a foundation for future development of ultra-efficient mechanism-adjustable electrocatalysis technologies.

Acute effects of cochleostomy and electrode-array insertion on compound action potentials in normal-hearing guinea pigs.

Electrocochleography (ECochG) is increasingly used in cochlear implant (CI) surgery, in order to monitor the effect of insertion of the electrode array aiming to preserve residual hearing. However, obtained results are often difficult to interpret. Here we aim to relate changes in ECochG responses to acute trauma induced by different stages of cochlear implantation by performing ECochG at multiple time points during the procedure in normal-hearing guinea pigs. Eleven normal-hearing guinea pigs received a gold-ball electrode that was fixed in the round-window niche. ECochG recordings were performed during the four steps of cochlear implantation using the gold-ball electrode: (1) Bullostomy to expose the round window, (2) hand-drilling of 0.5-0.6 mm cochleostomy in the basal turn near the round window, (3) insertion of a short flexible electrode array, and (4) withdrawal of electrode array. Acoustical stimuli were tones varying in frequency (0.25-16 kHz) and sound level. The ECochG signal was primarily analyzed in terms of threshold, amplitude, and latency of the compound action potential (CAP). Midmodiolar sections of the implanted cochleas were analyzed in terms of trauma to hair cells, modiolar wall, osseous spiral lamina (OSL) and lateral wall. Animals were assigned to cochlear trauma categories: minimal (n = 3), moderate (n = 5), or severe (n = 3). After cochleostomy and array insertion, CAP threshold shifts increased with trauma severity. At each stage a threshold shift at high frequencies (4-16 kHz) was accompanied with a threshold shift at low frequencies (0.25-2 kHz) that was 10-20 dB smaller. Withdrawal of the array led to a further worsening of responses, which probably indicates that insertion and removal trauma affected the responses rather than the mere presence of the array. In two instances, CAP threshold shifts were considerably larger than threshold shifts of cochlear microphonics, which could be explained by neural damage due to OSL fracture. A change in amplitudes at high sound levels was strongly correlated with threshold shifts, which is relevant for clinical ECochG performed at one sound level. Basal trauma caused by cochleostomy and/or array insertion should be minimized in order to preserve the low-frequency residual hearing of CI recipients.

A fully printed ultrafast Si/WS2 quantum dot photodetector with very high responsivity over the UV to near-infrared region.

Two-dimensional (2D) semiconducting material-based photodetectors (PDs) with high responsivity and fast photo-response are of great interest for various applications such as optical communications, biomedical imaging, security surveillance, environmental monitoring, etc. Additive manufacturing such as 2D printing is a potentially less cumbersome and cost-effective alternative to conventional microdevice fabrication processes used in the production of PDs. Here, we have fabricated a Si/WS2 quantum dot-based heterostructure PD with a very short electrode gap of 40 μm by a simple printing process. The printed p-Si/n-WS2 PD shows an excellent photo-to-dark current ratio of 5121 under 405 nm illumination (23.8 mW cm-2). The printed photodetector exhibits a peak responsivity of 126 A W-1 and a peak detectivity of 9.24 × 1012 Jones over a very broad wavelength range (300-1100 nm), which is much superior to commercial Si PDs. A high external quantum efficiency of 3.9 × 104% and an ultrafast photoresponse (7.8 μs rise time and 9.5 μs fall time) make the device an attractive candidate as an efficient photodetector. The origin of high-performance photodetection is traced to a nearly defect-free interface at the heterojunction, leading to highly efficient charge separation and high photocurrent. Finally, the 2D-printed device exhibits good photodetection even in self-powered conditions, which is very attractive.

Electrophoretic mobilization in capillary isoelectric focusing by a weak acid or an acidic ampholyte as catholyte assessed by computer simulation.

Capillary isoelectric focusing (CIEF) with cationic electrophoretic mobilization induced via replacing the catholyte with the anolyte or a solution of another acid or amino acid was investigated by computer simulation for a wide range pH gradient bracketed between two amphoteric spacers and short electrode vials with a higher id than the capillary. Dynamic simulations provide insight into the complexity of the mobilizing process in a hitherto inaccessible way. The electrophoretic mobilizing process begins with the penetration of the mobilizing compound through the entire capillary, is followed by a gradual or steplike decrease of pH, and ends in an environment with a non-homogenous solution of the mobilizer. Analytes do not necessarily pass the point of detection in the order of decreasing pI values. Cationic mobilization encompasses an inherent zone dispersing and refocusing process toward the capillary end. This behavior is rather strong with phosphoric acid and citric acid, moderate with aspartic acid, glutamic acid (GLU), formic acid, and acetic acid and less pronounced in the absence of the cathodic spacer. The data reveal that optical detectors should not be placed before 90% of capillary length. Aspartic acid, GLU, formic acid, and acetic acid provide an environment with a continuously decreasing pH that explains their successful use in optimized two-step CIEF protocols.

Slim Modiolar Electrode Placement in Candidates for Electroacoustic Stimulation.

To determine rates of hearing preservation and performance in patients who met candidacy for electroacoustic stimulation (EAS) and were implanted with a slim modiolar electrode (CI532 or CI632). Adult patients meeting Food and Drug Administration criteria for electroacoustic stimulation (preoperative low-frequency pure-tone average [LFPTA] less than 60 dB at 125, 250, and 500 Hz and monosyllabic word scores between 10% and 60% in the ear to be implanted), who received a slim modiolar electrode were included. Main outcome measures included rates of hearing preservation, defined as a LFPTA ≤80 dB at 125, 250, and 500 Hz, as well as postoperative low-frequency pure-tone threshold shifts, consonant-Nucleus-Consonant (CNC) word scores and AzBio sentences in noise scores. Forty-six patients met inclusion criteria during a 4-year period. Mean (standard deviation) preoperative LFPTA was 34.5 (13.0) dB, and 71.7% had preserved hearing at initial activation. The mean LFPTA shift in patients who preserved hearing at initial activation was 19.7 (14.6) dB, compared with 62.6 (17.7) dB in patients who did not preserve hearing as per our definition. Perioperative steroid use was not different in patients with and without preserved hearing (X 2 (1, N = 46) = 0.19, p = .67, V = 0.06). One year after surgery, 57% of patients had a decline in LFPTA >80 dB and were no longer considered candidates for EAS, with 34.7% still retaining low-frequency thresholds ≤80 dB. CNC word scores at 1 year were 69.9% and 61.4% among individuals with and without preserved low-frequency hearing respectively, measured in their CI ear alone, in their regular listening condition of EAS or electric only ( t (32) = 1.13, p = 0.27, d = 0.39, 95% CI = -6.51, 22.86). Device use time did not differ between groups. Among adults with preserved residual hearing at 1 year (n = 16), 44% used EAS, although there was no significant difference in performance between EAS users and nonusers with preserved hearing. Loss of residual hearing over time did not result in a decline in speech perception performance. The present study demonstrated favorable early rates of hearing preservation with a slim modiolar array. Performance was not significantly different in individuals with and without preserved low-frequency acoustic hearing, independent of EAS use. Compared with reports of short electrode use, the loss of residual hearing in patients implanted with this array did not impact speech perception performance.

Fabrication of Short Circuit-Preventing Electrodes with a Self-assembled Monolayer on Flashlight-Sintered Porous Copper Nanofilms

Fabrication of Short Circuit-Preventing Electrodes with a Self-assembled Monolayer on Flashlight-Sintered Porous Copper Nanofilms

Development of Highly-Efficient CO2 Electrolysis Cell Stacks

Low-temperature CO2 electrolysis technology, which converts CO2 into valuable products, has attracted attention for its potential to mitigate climate change caused by global warming. Various products, such as CO and ethylene glycol, can be obtained from electrochemical reactions [1,2]. CO, a useful raw material for hydrocarbons, is a particularly simple product. In order to implement an industrial-scale low-temperature CO2 electrolysis system, we must further reinforce the properties of the CO2 electrolysis cell: namely, energetic (energy conversion) efficiency, CO2 conversion rate (current density and scaling) and durability. For realizing high energetic efficiency, decreasing ohmic resistance and overvoltage is required. Therefore, a zero-gap electrolysis cell, which has short electrodes distance leading to lower ohmic resistance, has been adopted. The zero-gap configuration contains a membrane electrode assembly (MEA) constructed from cathode and anode electrodes and a diaphragm. Anion exchange membranes (AEMs) have been mainly used in past research as the diaphragm, however, the AEMs have several shortcomings for practical use as the diaphragm, e.g., low thermal stability, weak mechanical strength and high cost.In this work, we have focused on porous membranes as a novel diaphragm which is more suitable for overcoming those instabilities and costs. We have achieved an increase in energetic efficiency of the zero-gap CO2 electrolysis cell using the porous membrane when compared to that of AEMs. We have experimentally revealed higher ion permeability, lower ohmic resistance and lower overvoltage when using the porous membrane, resulting in improvement of the energetic efficiency. Regarding CO2 conversion rate and durability, we have developed a large-scale cell stack constructed with ten layers of a 100 cm2 size cell and demonstrated durable operation over one month.This work is partially supported by the Ministry of the Environment, Government of Japan.[1] Y. Kofuji, A. Ono, Y. Sugano, A. Motoshige, Y. Kudo, M. Yamagiwa, J. Tamura, S. Mikoshiba and R. Kitagawa, Chem. Lett. 50, 482 (2021).[2] J. Tamura, A. Ono, Y. Sugano, C. Huang, N. Hideyuki, and S. Mikoshiba, Phys. Chem. Chem. Phys. 17, 26072 (2015).

Electrode wear investigation of aluminium spot welding by motion overlay

The amount of aluminium sheets in future body-in-white concepts is still on the rise. There is a need for optimizing the joining techniques, caused by the different characteristics compared to the established steel components. Especially the electrode life for resistance spot welding as a reliable and established process needs to be improved. One reason for the short electrode life when welding aluminium is the insulating effect of the aluminium oxide layer. One possibility to reduce the electrode wear is the mechanical destruction of the oxide layer before the welding. This paper describes the influence of a translational and rotational electrode movement on the electrode wear. The oxide layer destruction is detected by resistance measurement. It could be shown that the destruction of the oxide layer already occurs at low movements. However, a homogeneous, large-area destruction is necessary for a wear reduction.

High performance liquid-solid tubular triboelectric nanogenerator for scavenging water wave energy

The exploitation of clean and renewable wave energy has attracted fully concern in the world wide. In this work, a high-output array of liquid-solid tubular triboelectric nanogenerator (LST-TENG) based on the contact electrification between PTFE and water was proposed. The low-frequency wave motion was simulated to systematically analyze the impacts of several factors on the electrical performance of LST-TENG to provide guidance for the fabrication of the PTFE tube and the electrode arrangement for the achievement of high wave energy transition. An increase in the length/diameter of the tube, distance and width of the electrodes made a positive impact on the output performance of LST-TENG unit. A typical LST-TENG here should be an optimum water-to-cylinder volume ratio, as well it is better to wrap electrodes from the end, especially for short electrodes. Moreover, the influences of the motion characteristics including the angle, frequency and amplitude of oscillation was also considered. To achieve high peak output, we compared the output performance of series-wound and parallel LST-TENG arrays to find that parallel connection showed linear rise with the number of units is a feasible approach to get peak output voltage exceed 500 V, which extended the potential application of the LST-TENG arrays. At the optimal operating condition, the power density achieved 228 mW/m3. This study provided the assessment of the power quality of LST-TENG and considering the diverse motion of the TENG units integrated into the blocks, which is expected to be the reference for the optimization of LST-TENG in the future.