Electric Current Research Articles

Bioelectrical stimulation therapy for muscle injuries in aerobics athletes

This article aims to explore the recovery effect of the bioelectrical stimulation therapy on muscle injuries in aerobics athletes. Non-invasive medical techniques are adopted to activate muscle tissue through electrical currents, promoting muscle contraction ability and functional recovery. This article selects 100 aerobics athletes with muscle injuries through questionnaire surveys and interviews. The Modulo Plus electrical stimulation device is used, and personalized treatment plans are set. Muscle changes before and after treatment are monitored using electromyography and ultrasound technology. In the single-blind experiment, in the fourth week, the pain score of the experimental group decreases to 2.4 points; the functional recovery score increases to 75.2 points; the flexibility measurement reaches 19.2 cm. In the case-control study, the bioelectrical stimulation therapy cures all athletes in the sixth week, exceeding the conventional therapy’s 35 patients, and has a lower recurrence rate. In the cohort study, athletes who use the bioelectrical stimulation therapy for a long time have a shorter average recovery time of 15.3 days and a recurrence rate of 16%. In the muscle recovery experiment, in the eighth week after treatment, the electromyographic activity level of the experimental group increases to 58.6 μV; the muscle thickness increases to 4.3 mm; the echo intensity increases to 63.1 dB; the fatigue characteristic score drops to 2.1. These data indicate that the bioelectrical stimulation therapy has significant effects in reducing pain, promoting functional recovery, improving flexibility, shortening recovery time, and reducing recurrence rates and pain scores, thereby providing an effective treatment option for the recovery of muscle injuries in aerobics athletes.

Highly stretchable and strain-insensitive multilayered electromagnetic interference shielding films prepared via a simple soaking-infiltration strategy

Stretchable electromagnetic interference (EMI) shielding films are crucial for wearable electronics. However, it is challenging to further endow the EMI shielding films with good stretchability and satisfactory EMI shielding effectiveness (EMI SE) under large strains. Herein, we successfully prepared high-performance stretchable polydimethylsiloxane (PDMS)/single-walled carbon nanotube buckypaper (SWNT BP)/PDMS EMI shielding films with multi-graded conductive networks via a soaking-infiltration strategy. In this multilayered film, infiltration layers of SWNT/PDMS were particularly created between elastic PDMS and brittle SWNT BP. Owing to the multilayered structure and conductivity compensation effects arising from infiltration layers, our EMI shielding films exhibited excellent EMI SE of 34.2 dB with high stretchability of >400 %. The outstanding EMI SE could be well maintained under large strains. At <50 % strain, the relative change in EMI SE (|ΔSE/SE0|) remained consistently below 10 %, while at even 100 % strain, |ΔSE/SE0| was only ∼35 %. Furthermore, we proposed a parallel-series hybrid model to describe electrical conduction in straining films. Due to their excellent conductivity under strain, the films could also serve as stretchable Joule heaters. This work provides a novel and simple approach for constructing strain-insensitive conductive films, with potential applications in stretchable EMI shielding and thermal management.

Analysis on density of states and ION/IOFF ratio of GaN/GaN-graphene nanoribbon tunnel FET for enhanced bio-sensing applications

Abstract This research introduces a new analytical model that studies the effect of ferro-dielectric on the operational performance of TFETs doped with halogens. The effect of source and drain depletions, voltage-drain &amp; gate, thickness and capacitance of gate insulator are all investigated in this study. Accurate measurements of the surface potential are required to ascertain the transconductance, gate-to-drain capacitance, and lateral electric field of the device. Our model, which employs Ferroelectric Halo-Doped double gate (FHDD)-gated device designs, has been demonstrated to produce results that nearly match those produced from TCAD simulations. This was accomplished by doing a comparative analysis of the outcomes derived from both sets of simulations. Furthermore, the performance of the suggested structure of TFET, which integrates a dielectric of Fe and GaN heterostructure, surpasses that of other similar devices (fT) in terms of ON current, ON/OFF ratio, transconductance, and cut-off frequency. A ferroelectric dielectric was used to create a ferroelectric heterostructure. This study also centers on the creation and application of a graphene nanoribbon field effect transistor (GNR-TFET) to detect sugar molecules, specifically fructose, xylose, and glucose. The detecting signal is generated by utilizing the fluctuation in the electrical current of the GNR-TFET caused by the presence of individual sugar molecules. The GNR-TFET exhibits noticeable variations in the density of states, transmission spectrum, and current when exposed to individual sugar molecules. The sensor under investigation is being developed and examined using a combination of semi-empirical modeling and non-equilibrium Green's functional theory (SE + NEGF). According to the research, the modified GNR TFET has the ability to quickly and accurately detect individual sugar molecules in real-time.&amp;#xD;

ON THE HEAT CONDUCTION EQUATION AND THE HEAT DISSIPATION FUNCTION IN ANISOTROPIC REACTING FLUID MIXTURES WITH MAGNETIC RELAXATION

In some previous papers, within the framework of the thermody namics of irreversible processes with internal variables, a linear theory for magnetic relaxation phenomena in anisotropic mixtures, consisting of n reacting fluid components, was developed. In particular, assuming that the macroscopic magnetization m can be split in two irreversible parts m = m(0) + m(1) a generalized Snoek equation was derived. In this paper we derive for these reacting anisotropic mixtures the heat conduction equation. We show that the heat dissipation function is due to the chemical reactions, the magnetic relaxation, the electric conduc tion, the viscous, magnetic, temperature fields and the diffusion and the concentrations of the n fluid components. Also, the Snoek and De Groot special cases are studied. The obtained results find applications in nuclear resonance, in biology, in medicine and other fields, where different species of molecules have different magnetic susceptibilities and relaxation times and contribute to the total magnetization.

Toward quantitative thermoelectric characterization of (nano)materials by in-situ transmission electron microscopy

We explore the possibility to perform an in-situ transmission electron microscopy (TEM) thermoelectric characterization of materials. A differential heating element on a custom in-situ TEM microchip allows to generate a temperature gradient across the studied materials, which are simultaneously measured electrically. A thermovoltage was induced in all studied devices, whose sign corresponds to the sign of the Seebeck coefficient of the tested materials. The results indicate that in-situ thermoelectric TEM studies can help to profoundly understand fundamental aspects of thermoelectricity, which is exemplary demonstrated by tracking the thermovoltage during in-situ crystallization of an amorphous Ge thin film. We propose an improved in-situ TEM microchip design, which should facilitate a full quantitative measurement of the induced temperature gradient, the electrical and thermal conductivities, as well as the Seebeck coefficient. The benefit of the in-situ approach is the possibility to directly correlate the thermoelectric properties with the structure and chemical composition of the entire studied device down to the atomic level, including grain boundaries, dopants or crystal defects, and to trace its dynamic evolution upon heating or during the application of electrical currents.

Study on the Damage Mechanism of an H62-Cu/7075-Al Tribo-Pair Under the Influences of Current Direction and Density.

In the present study, we used 7075 Al-H62 Cu and H62 Cu-7075 Al pairs to study the effects of current density and direction on their tribological properties and on the damage caused by the current-carrying friction and wear. We found that, when the current density increased from 0 A/mm2 to 79.61 A/mm2, the coefficients of friction for both pairs decreased. Results obtained after wear indicate that the current direction influences the electromigration between the two tracks, leading to different kinds of damage on the worn surface. In the case of the 7075 Al-H62 Cu pair, damage mainly involved mechanical wear at low current densities. As the current density increased, electro-erosion damage gradually became more dominant. Under the action of a large electric arc, the material surface was severely eroded, and a dense oxide film formed on the material contact surface, ultimately leading to the failure of electrical conduction between the materials. In the case of the H62 Cu-7075 Al pair, damage mainly involved mechanical wear. A layer of copper film was found on the surface of the worn aluminum pin, which caused its mass to be greater than it was before wear.

Taguchi, Grey Relational Analysis, and ANOVA Optimization of TIG Welding Parameters to Maximize Mechanical Performance of Al-6061 T6 Alloy

This study presents a comprehensive investigation into optimizing Tungsten Inert Gas (TIG) welding parameters to enhance the mechanical performance of the widely used Al-6061 T6 alloy, specifically in a double V joint configuration with a plate thickness of 6 mm, for aerospace applications. The Taguchi method was employed to design the experiments, providing a robust framework for analyzing the influence of the electrical current, voltage, and gas flow rate on weld quality. Additionally, a Grey Relational Analysis (GRA) and an Analysis of Variance (ANOVA) were used to validate the optimal welding parameters and quantify the significance of each factor. The optimized parameters were determined to be an amperage of 180 A, a voltage of 18 V, and a gas flow rate of 10 L/min, resulting in significant improvements of up to 40% in tensile strength and 23% in hardness, demonstrating the effectiveness of the optimized conditions. The findings provide valuable insights into welding metallurgy, offering practical guidelines for enhancing high-performance welded joints in critical industrial applications. This study underscores the potential of combining Taguchi, GRA, and ANOVA methodologies to achieve superior mechanical properties and reliability in welded structures.

Reconstructing ventricular cardiomyocyte dynamics and parameter estimation using data assimilation

Cardiac ventricular myocyte action potential dynamics are regulated by intricate and nonlinear interactions between the cell transmembrane potential and ionic currents and concentrations. Present technology limits the ability to measure transmembrane potential and multiple ionic currents simultaneously, which narrows the scope of experiments to provide a complete snapshot of the cardiac myocyte state. This limitation presents an obstacle for understanding how perturbations can trigger arrhythmias and more broadly how the myocyte responds to different conditions, such as changes in pacing rate or responses to drug treatment. In this study, we demonstrate that a data-assimilation approach can successfully reconstruct and predict the dynamics of a heterogeneous virtual cardiac ventricular myocyte population in the presence of parameter uncertainty. A population of heterogeneous cardiac ventricular myocytes is generated by varying ionic current conductance parameters, and additional observational uncertainty is mimicked by the addition of Gaussian noise to the transmembrane potential. We demonstrate that the data-assimilation approach accurately reconstructs transmembrane potential, with error less than the magnitude of the noise. Further, the data-assimilation approach successfully estimates the conductances of ionic currents generally with high accuracy and requiring low computational time. As a proof of concept, we apply the data-assimilation approach to reconstruct action potential dynamics from optical mapping experiments in an ex vivo isolated guinea pig heart. Critically, we demonstrate that the ionic conductance parameters estimated from a recording at one pacing frequency can accurately predict action potential dynamics at different rates.

Alphabet Handwriting Recognition: From Wood-Framed Hydrogel Arrays Design to Machine Learning Decoding.

Handwriting recognition is a highly integrated system, demanding hardware to collect handwriting signals and software to deal with input data. Nonetheless, the design of such a system from scratch with sustainable materials and an easily accessible computing network presents significant challenges. In pursuit of this goal, a flexible, and electrically conductive wood-derived hydrogel array is developed as a handwriting input panel, enabling recognizing alphabet handwriting assisted by machine learning technique. For this, lignin extraction-refill, polypyrrole coating, and polyacrylic acid filling, endowing flexibility, and electrical conduction to wood are sequentially implemented. Subsequently, these woods are manufactured into a 5×5 array, creating a matrix of signals upon handwriting. Efficient handwritten recognition is then achieved through appropriate manual feature extraction and algorithms with low complexity within a computing network, as demonstrated in this work, the strategic choice of expertise-based feature engineering and simplified algorithms effectively boost the overall model performance on handwriting recognition. With potential adaptability, further applications in customized wearable devices and hands-on healthcare appliances are envisioned.

Impacts of single Shockley-type stacking faults on current conduction in 4H-SiC PiN diodes

The impacts of single Shockley-type stacking faults (1SSFs) on the electrical characteristics of 4H-SiC PiN diodes were examined by fabricating the PiN diodes containing the 1SSF monolayer in the active area with a covering ratio of unity and evaluating the forward current–voltage (I–V) characteristics at various temperatures from 296 to 523 K. The measured I–V characteristics were compared with the previous results for Schottky barrier diodes (SBDs) containing the 1SSF monolayer. Based on the comparison, we clarified the similarity and differences between the impacts of the 1SSFs on the unipolar and bipolar conductions. The forward current conduction of the PiN diodes is limited by the 1SSF similar to that of the SBDs, while the forward current in the PiN diodes exceeds that in the SBDs at elevated temperatures. The difference was attributed to the contribution of hole and recombination currents, the insights into which were obtained by analyzing several experimental results, including dependences of the forward current on the temperature and thickness of the blocking-voltage layer. A simulation analysis was also conducted by adopting the model proposed in the previous study.

Investigation on piezoresistive properties of reduced graphene oxide treated glass textiles based multifunctional sensors

AbstractGlass fabric‐reinforced composites (GFRC) and other revolutionary engineered materials find extensive application in the aerospace, construction, and automobile sectors. It is challenging to predict damage under real‐time stresses due to the anisotropic behavior of composite materials. This study presents the development of a glass textile‐based multifunctional composite sensor and demonstrates its application as a change in resistance or gauge factor in structural health monitoring (SHM) systems. This sensor is coated with reduced graphene oxide (rGO) nanomaterial. Its electrical resistance is evaluated by examining the concentration of nanoparticles and varying geometrical parameters. A three‐point bending method assessed the piezoresistive behavior of the integrated sensor in the GFRC. The impact of sensor width and relative placements in the material's thickness direction within the composite samples is evaluated. Cyclic flexural testing was also performed to demonstrate real‐world applications. The research concludes that it can be utilized as a damage assessment technique for GFRC. The developed sensor can be used to provide an electrically conductive path or as a resistor in the field of E‐textiles. The developed piezoresistive sensor has the flexibility to be used as a multifunctional sensor for multiple purposes, such as force, torque, weight, pressure, flow, acceleration sensors, etc.Highlights Glass textile‐based multifunctional materials are reported as strain‐monitoring sensors. Tailored sensor resistance could be achieved through rGO current conduction paths. Glass textile‐based sensors could potentially be used in the field of E‐textile.

A crumpled sphere-like NiMn metal-organic phosphate as electrode material for electrochemical supercapacitor

The present study investigates a crumpled sphere-like binary Ni Mn metal–organic phosphate (Ni10Mn1-MOPh) sample for its potential application in electrochemical supercapacitors. Additionally, control samples of NixMny-MOPhs with varying proportions of Ni and Mn were also prepared. It is noteworthy that NixMny-MOPh samples with different molar ratios of Ni:Mn display different morphologies and electrochemical supercapacitor properties. Compared with other as-prepared NixMny-MOPhs, Ni10Mn1-MOPh modified electrode showed more complete sphere, bigger active surface area, and faster electrical conduction, applying for the hydrothermal condition is pivotal factor for the practical applications of NixMny-MOPhs. The synthesized Ni10Mn1-MOPh demonstrates a remarkable specific capacitance value of 986.8F/g at 2 A/g and exhibits exceptional reversible charge/discharge capability with an approximate retention rate of 81.9 % after 5000 cycles at 6 A/g. As a proof-of-concept, we synthesized bare Ni-MOPh and MnO2, thereby further confirming that the optimization electrochemical performance is associated with the synergistic effect of diverse active metals, their respective ratios, and the appropriate morphology of the NiMn-MOPh samples.

Electrical properties and conduction mechanisms of ε-GaSe films for selector and phase-change memory applications

Owing to the pressing requirement for advanced memory solutions driven by explosive data growth, nonvolatile and fast-operating 1S1R structured XPoint memory has become a prominent focus, with recent interest shifting towards the 1S structured selector-only memory. The use of chalcogenide-based materials in these technologies constrains the application of such memories because of their complex quaternary compositions. This study investigated the previously unreported potential of GaSe, a simple binary Se-based chalcogenide, for applications as a selector and phase-change memory (PCM). In this study, ε-GaSe thin films were deposited using thermal evaporation and subsequently annealed in a Se atmosphere for 1 and 2 h. These ε-GaSe thin film devices incorporated metal–insulator–metal construction to exhibit both selector and PCM characteristics. The ε-GaSe device that was Se-annealed for 1 h demonstrated superior performance with a lower threshold voltage and off current, high selectivity as a selector, and reduced set voltage and reset power as a PCM. These characteristics render the proposed device a highly promising candidate for dual selector/PCM applications. To explain the electrical behavior of the ε-GaSe device, we propose the conduction mechanism model depending on the Se-annealing time, which is related to the change in the physical properties of ε-GaSe.

Giant antisymmetric magnetoresistance arising across optically controlled domain walls in the magnetic Weyl semimetal Co3Sn2S2

Domain walls (DWs) in magnetic materials host various interesting magneto-transport phenomena. Recent theoretical proposals focusing on DWs of magnetic Weyl semimetals (mWSMs) suggest the emergence of even more exotic transport owing to topologically protected Weyl domains with opposite chirality. However, techniques for controlling and characterizing DWs in mWSMs have not yet matured sufficiently to identify the distinct features of electrical conduction on DWs. Here, by adopting an optical technique to manipulate magnetic domains in mWSM Co3Sn2S2 Hall-bar devices, we discover giant antisymmetric magnetoresistance arising across a DW formed by serially connected upward- and downward-magnetized Weyl domains. This phenomenon originates from the large tangent of the Hall angle associated with the intrinsic anomalous Hall effect in the oppositely magnetized Weyl domains. Furthermore, we quantitatively evaluate DW resistance by systematically controlling the number of DWs. These results underscore the promising avenue of Weyl DW engineering for advanced research on topological magnets.

Novel biomimetic sandwich-structured electrospun cardiac patches with moderate adhesiveness and excellent electrical conductivity

Clinical cardiac patches exhibit unsatisfied biocompatibility, low adhesion, and inadequate compliance and suboptimal mechanical properties for cardiac disorders repair. To address these challenges, herein we have innovatively proposed a biomimetic nanofiber electrospun membrane with a sandwich structure strategy. The composite patch comprises a stretchable polyurethane (PU) as basic material, then infiltrated with biocompatible silk fibroin methacryloyl (Silk-MA) as the middle layer via electrospinning and finally covered with Bio-ILs (chemically modified biocompatible ionic liquids) to impart electrical conductivity. Results indicated that the incorporation of Bio-ILs significantly enhances the conductivity reaching 2877 mS/m; particularly due to the positive charges of Bio-ILs, the composite film exhibits mild adhesive properties, inducing minimal damage to the substrate tissue. Furthermore, the basic PU of bilayer nanofiber membrane increased the film's stretching strain to approximately 250%, the Silk-MA hydrogel coating changed the film from hydrophobic to hydrophilic, creating a favorable and biocompatible microenvironment. Finally, in vitro experiments on cardiomyocytes confirmed that the material exhibits low cytotoxicity and excellent biocompatibility. Overall, the biomimetic sandwich electrospun membrane could restore electrical conduction and synchronized contraction function, providing a promising strategy for the treatment of cardiac tissue engineering.

Design of Intercalated Graphene/CNTs nanocomposite lubricants with load-bearing and their intelligent electric current-controlled friction performance

The poor dispersion stability and load-carrying properties of Gra may limit its further application in lubrication. The Gra/CNTs nanocomposite additive (abbreviated as GC) was successfully prepared in this paper. The micromorphology of Gra/CNTs was indicated that some carbon nanotubes were inserted into the interlayer of Gra layers. The different content of GC additive was added to hexadecane (C16). By comparison with that of pure C16, the average coefficient of friction (COF) of 0.3 wt% GC-C16 was reduced by 45 %, and its wear volume was also reduced by 43.75 %, which were attributed to the excellent interfacial load-bearing capacity of CNTs. The electric current-controlled COF of 1.0 wt% GC-C16 was decreased by 18 % compared to that of test without electric current. The electric current could break down the additive into finer structures, effectively bearing the load and repairing the worn surface. Therefore, GC nanocomposite additive acted as a remarkable role in the application of anti-friction area.

The effect of the addition of 2-dimensional manganese-oxide to ceria on density and electrical conduction

Gadolinium-doped ceria (GDC), a prominent solid electrolyte for solid oxide fuel cells, is known to have poor sinterability and requires high temperatures for densification. To address this issue, transition-metal oxides have frequently been used as sintering aids to enhance the sinterability of ceria. In this study, a two-dimensional (2D) sintering aid, distinct from conventional three-dimensional structures, was used. Specifically, 2D MnO2 with nanometer-thickness, produced by a chemical exfoliation method, was utilized to improve the sinterability of GDC. GDC with the sintering additive (2D MnO2) was sintered at various temperatures (800–1200 °C). The addition of 2D MnO2 successfully reduced the sintering temperature. As a result, the sample with high relative density demonstrated high oxygen ionic conduction, even though it was sintered at a lower temperature.

Reconfigurable magnonic crystals: Spin wave propagation in Pt/Co multilayer in saturated and stripe domain phase

To control the spin wave (SW) propagation, external energy sources such as magnetic fields, electric currents, or complex nanopatterning are used, which can be challenging at the deep nanoscale level. In this work, we overcome such limitations by demonstrating SW propagation in Pt/Co multilayers at a remanent state controlled by stripe domain patterns, using Brillouin light scattering and micromagnetic simulations. We show that parallel stripes with a periodicity around 100 nm exhibit reconfigurability, as the stripes can be rotated by applying the in-plane field without damaging their shape. This allows us to study SW propagation perpendicular and parallel to the stripes. We observe multimodal SW spectra—three bands in perpendicular and five in parallel geometry. Numerical results allow us to identify all observed modes and to explain the differences between two configurations by the unequal contribution of all three magnetization components in the SW dynamics. We find that the experimentally measured non-reciprocal dispersion (for the wavevector perpendicular to the stripes) is not the breaking of time-symmetry but the asymmetry in intensity of the measured signals of two different low-frequency modes, which is due to the inhomogeneous SW amplitude distribution over the multilayer thickness and the limited light penetration depth. Our results pave the way for easy reprogrammability and high energy efficiency in nanomagnonics.

Efficiency And Effectiveness Of Circuit Arrangement And Placement Of Thermoelectric For The Design Of Utilizing Zinc Roof As An Electrical Source

&lt;p&gt;The problem related to electrical power sources commonly encountered in society is the frequent occurrence of rotating power outages or sudden blackouts, which disrupt activities for both communities and industries as they heavily rely on electrical power to meet their needs, both collectively and individually. In order to meet the needs of society and industry, Indonesia requires a sufficiently large energy supply. One renewable energy source that can be utilized is solar energy due to its easy availability, cleanliness, and cost-effectiveness. In this study, an experimental method is employed, which utilizes the heat from zinc roofs and converts it into electrical energy using thermoelectric generators. Testing is conducted by varying the circuit arrangements, including series, parallel, and combined configurations, as well as the number of thermoelectric modules (20, 30, and 42 modules), and placement locations on zinc roofs and house ceilings, to observe the output results in terms of voltage and electrical current. As observed from the test results presented in the graphs, the output voltage and current vary for each type of circuit. Based on the use of various circuit arrangements, it can be concluded that combining thermoelectric generators results in higher current and voltage values. The greater the number of thermoelectric modules, the larger the output value. There is a difference in output values between placement on zinc roofs and ceilings, with higher output values observed when installed on zinc roofs. This is due to direct contact between the hot side of the thermoelectric generator and the inner part of the zinc roof. All data obtained from these variations depend on the temperature difference between the hot and cold sides of the thermoelectric generator. The greater the temperature difference produced, the larger the voltage and current output from the circuit. This temperature difference affects the overall performance of the circuit.&lt;/p&gt;

Radiofrequency Ablation: Honoring the Pioneers of Modern Therapeutic Innovations.

Radiofrequency ablation (RFA) is a minimally invasive technique used to alleviate chronic pain by destroying pain-signaling nerve fibers. This procedure offers precise and focused pain relief, serving as an alternative to surgical and pharmacological treatments for chronic conditions such as arthritis, back pain, neck pain, and nerve pain. RFA has evolved over a long period, beginning with early work on electrical currents. Significant progress has been made in its application to pain management with continual technological improvements enhancing its safety and effectiveness. As technology and research continue to progress, RFA promises even greater efficacy and safety, enhancing the quality of life for patients with chronic pain. Additionally, as the understanding of pain mechanisms advances, RFA can be utilized as a procedure to treat a wider lexicon of chronic pain pathologies. This historical narrative outlines the history and clinical origins of RFA, the pioneers that pushed the development of the field, and the treatment's path to modern implications in chronic pain relief.