Values Of Electric Potential Research Articles

Spatially Selective Retinal Ganglion Cell Activation Using Low Invasive Extraocular Temporal Interference Stimulation.

Conventional retinal implants involve complex surgical procedures and require invasive implantation. Temporal Interference Stimulation (TIS) has achieved noninvasive and focused stimulation of deep brain regions by delivering high-frequency currents with small frequency differences on multiple electrodes. In this study, we conducted in silico investigations to evaluate extraocular TIS's potential as a novel visual restoration approach. Different from the previously published retinal TIS model, the new model of extraocular TIS incorporated a biophysically detailed retinal ganglion cell (RGC) population, enabling a more accurate simulation of retinal outputs under electrical stimulation. Using this improved model, we made the following major discoveries: (1) the maximum value of TIS envelope electric potential ([Formula: see text] showed a strong correlation with TIS-induced RGC activation; (2) the preferred stimulating/return electrode (SE/RE) locations to achieve focalized TIS were predicted; (3) the performance of extraocular TIS was better than same-frequency sinusoidal stimulation (SSS) in terms of lower RGC threshold and more focused RGC activation; (4) the optimal stimulation parameters to achieve lower threshold and focused activation were identified; and (5) spatial selectivity of TIS could be improved by integrating current steering strategy and reducing electrode size. This study provides insights into the feasibility and effectiveness of a low-invasive stimulation approach in enhancing vision restoration.

On complexity of colloid cellular automata

The colloid cellular automata do not imitate the physical structure of colloids but are governed by logical functions derived from them. We analyze the space-time complexity of Boolean circuits derived from the electrical responses of colloids-specifically ZnO (zinc oxide, an inorganic compound also known as calamine or zinc white, which naturally occurs as the mineral zincite), proteinoids (microspheres and crystals of thermal abiotic proteins), and their combinations in response to electrical stimulation. To extract Boolean circuits from colloids, we send all possible configurations of two-, four-, and eight-bit binary strings, encoded as electrical potential values, to the colloids, record their responses, and infer the Boolean functions they implement. We map the discovered functions onto the cell-state transition rules of cellular automata-arrays of binary state machines that update their states synchronously according to the same rule-creating the colloid cellular automata. We then analyze the phenomenology of the space-time configurations of the automata and evaluate their complexity using measures such as compressibility, Shannon entropy, Simpson diversity, and expressivity. A hierarchy of phenomenological and measurable space-time complexity is constructed.

Thermodynamic topology of phantom AdS black holes in massive gravity

In this work, we explore the thermodynamic topology of phantom AdS black holes in the context of massive gravity. To this end, we evaluate these black holes in two distinct ensembles: the canonical and grand canonical ensembles (GCE). We begin by examining the topological charge linked to the critical point and confirming the existence of a conventional critical point (CP1) in the canonical ensemble (CE), this critical point has a topological charge of −1 and acts as a point of phase annihilation, this situation can only be considered within the context of the classical Einstein–Maxwell (CEM) theory (η=1), while no critical point is identified in the GCE. Furthermore, we consider black holes as a topological defect within the thermodynamic space. To gain an understanding of the local and global topological configuration of this defect, we will analyze its winding numbers, and observe that the total topological charge in the CE consistently remains at 1. When the system experiences a pressure below the critical threshold, it gives rise to the occurrence of annihilation and generation points. The value of electric potential determines whether the total topological charge in the GCE is zero or one. As a result, we detect a point of generation point or absence of generation/annihilation point. Based on our analysis, it can be inferred that ensembles significantly impact the topological class of phantom AdS black holes in massive gravity.

Enhancing the PEEK composites-titanium interface performances through electrochemical treatment in fibre-metal laminates for aerospace applications

In this work, different surface treatments were investigated to improve the adhesion between grade 5 titanium alloy and carbon fibre-reinforced PEEK composites for aerospace applications. Three types of processes were compared: mechanical treatment (MT), carried out by sander with #80 grit sandpaper, chemical treatment, using a silane coupling agent (SIL) and electrochemical treatment, performed by anodic oxidation. The latter was performed by using an ethylene glycol solution composed of 0.5%wt of ammonium fluoride (NH4F) and variable volume content of deionized water: 5%v/v, 20 % v/v, 50 % v/v. The ammonium fluoride content was fixed, while the ethylene glycol percentage depend on the variation of water volume. Two values of electric potential were evaluated: 30V and 50V. Finally, for each potential and water content, three different anodizing times were studied: 10 min, 30 min, and 60 min. Morphology studies were performed through Scanning electron microscopy to evaluate how the anodizing parameters could affect the shape of the nanotubes (NTs) layers. Moreover, short beam shear tests were carried out to evaluate the achieved improvement given by the different surface treatments.

Periodic electroosmotic flow of nanofluids with slip-dependent high zeta potential

The time periodic electroosmotic flow of nanofluids is investigated analytically in a hydrophobic microchannel. In this study, we consider the interdependence relationship between the wall electrical potential and slip. According to the non-linear slip-dependent zeta potential, we obtain an analytical solution of electrical potential for arbitrary value of wall electrical potential. Subsequently, we give the analytical integration expression of time periodic electroosmotic velocity of nanofluids. Based on the obtained electrical potential distribution, the oscillating flow velocity and rate are calculated numerically. The flow characteristics are determined by the oscillating frequency of electrical field, the volume fraction of nanoparticles and wall electrical potential. The noteworthy results are that, the oscillating electrical field can result in the oscillation of nanofluids. However, such oscillation is strongly dependent on the electrical field frequency and the flow characteristics are significantly different for various frequencies. Moreover, when the nanoparticles are introduced into the time periodic electroosmotic flow, the oscillation can be restrained. This may be helpful to understand the electrohydrodynamic instability of nanofluids.

Non-spontaneous symmetry breaking, chaos, and universality in 2D superconducting phase transition

This research paper explores the intriguing phenomenon of the superconductor-metal–insulator phase transition in thin films, examining it from a theoretical standpoint. Our study revolves around the proposition that the process of U(1) symmetry breaking in the Landau–Ginzburg theory might not be entirely spontaneous. Building on this insight, we derive critical parameters characterizing the superconducting phase transition. Our findings demonstrate that the application of an electric field can effectively control the phase transition, leading to the suppression of the supercurrent at specific electric potential values, which is consistent with recent research. Furthermore, we have developed a robust relationship for the nonlinear resistivity that accurately simulates experimental measurements below the critical temperature. This derived relation adopts the form of logistic functions, providing a systematic framework to describe the system within the realm of chaos theory. Moreover, we establish a link with the Berezinskii–Kosterlitz–Thouless theory, highlighting the universality of the topological transition. However, this universality breaks down under the influence of multiple control parameters. To delve further into the underlying reasons for the collapse of universality, we turn to the study of Markus–Lyapunov fractals, which offers a deep understanding into the system’s behavior in the presence of varying external influences..

Experimental investigation of the fracture and damage evolution characteristics of flawed coal based on electric potential and acoustic emission parameter analyses

Flawed coal is the most common construction object in the mining process, and understanding its mechanical behavior and damage evolution is crucial for monitoring the stability of underground projects. In this work, uniaxial compression experiments on flawed coal were conducted, and the electric potential (EP) and acoustic emission (AE) signals were recorded synchronously. An in-depth study of the fracture mode and damage evolution characteristics of coal samples based on EP and AE responses was conducted. The results showed that (1) as loading proceeds, the coal body stress increases, the EP and AE values increase, and EP and AE are excited whenever the stress drop phenomenon occurs. With the gradual expansion of the initial flaws, the EP field and AE event distributions show regional differences. High-intensity EP anomaly bands are generated in the path of the main crack formation, and many high-energy AE events are generated. (2) The fractured behavior of the coal sample is dramatically altered by flaw inclination. When the flaw inclination increases, the AE signals show a shift from the common distributions of the six types to the concentrated distributions of the low amplitude–low frequency (LA–LF) and high amplitude–low frequency (HA–LF) types, the coal sample destruction modes are transformed from dominantly tensile to mixed tensile and shear, and the destruction mode is increasingly complicated. (3) It is possible to evaluate and analyze the damage evolution characteristics of the coal samples by defining the coefficient of variation (CV value) of the EP and the b value of the AE. Both a sudden increase in the CV value and a sudden decrease in the b value can be used as precursor information for coal failure. A two-parameter joint monitoring approach can be used to precisely and promptly warn about coal instability damage. The research results can provide theoretical support for the stability assessment of coal structures during the deep coal seam mining process and early warning of the occurrence of dynamic disasters.

Direct triboelectricity from friction of wheel tires on pavements

<p>Energy consumption in road and street traffic is significant and increasing. A partial recovery of this energy is the objective of the research briefly presented in the present paper. The proposed technique is totally innovative and has not been investigated, even through laboratory research, anywhere else. It aims to harvest triboelectric energy generated while wheel tires are directly rubbed against a pavement surface where oppositely charged electrodes are properly attached. The laboratory testing device consists of a rotating wheel bearing a vehicle tire, set up adequately to move down to a solid bench where flat bars, rods or tubes, susceptible to being oppositely charged by pairs, are attached. Metals, such as copper, bronze and aluminum, developing high electrical conductivity, were used in most experiments, as electrodes. Triboelectricity tests, under different placement of the electrodes regarding the wheel, were conducted in the laboratory and provided noticeable values of electric potential. Even more promising seem the results obtained following an intermittent application of the wheel load. Further experimentation introducing a much bigger wheel load, a different tire texture and other test improvements are ongoing, aiming at higher values of electric potential.<strong><em></em></strong></p>

The Results Comparison of Numerical and Analytical Methods for Electric Potential on Rectangular Pipes

Two methods can be used to solve the problem of electric potential distribution in a rectangular pipe: numerical and analytical. The analytical solution is obtained using the Laplace equation and the given boundary conditions to complete the solution in the form of a linear combination of sinusoidal and hyperbolic functions. While the numerical solution is obtained using the finite difference method in the Python programming language. The comparison between the analytical and numerical solutions shows that the two have a good fit. This can be seen from the graph of the electric potential distribution in the rectangular pipe produced by the two methods. Numerical solutions obtained using the finite difference method in the Python programming language provide accurate and efficient results in solving the problem of the electric potential distribution in rectangular pipes. The use of the first four terms in the analytical method and the selection of 4 observation points on the pipe, namely points A (3.33, 1.67), B (3.33, 3.34), C (6.67, 1.67), and D (6.67, 3.34) produces a difference in the electric potential value between analytical and numerical methods each point is 35.91%, 51.96%, 51.96%, and 35.91%. The value difference between analytical and numerical methods will be smaller if more terms are taken in the analytical calculation, and more observation points are considered on the pipe.

The impact of Morus alba L. leaf extract on intestinal ion transport. An in vitro study.

Morus alba L. (White mulberry), is an important and popular herbal plant of the Moraceae family. It has been widely used due to its therapeutic properties, which include antidiabetic, antibacterial, anti-inflammatory, cardiovascular, and hypolpidemic activity. The present study evaluates the effects of aqueous white mulberry leaf extract on the transepithelial ion pathway in the rabbit colon epithelium (n=48), using electrophysiological methods. In addition, the antioxidant potential and the chemical composition of the extract were determined. A mechanical-chemical stimulation with white mulberry in RH fluid (MB-RH) caused a statistically significant (p<0.001) increase in the transepithelial electrical potential difference, from -0.130 to -0.685mV. Gentle washing of the intestine with white mulberry in bumetanide, used as inhibitor of transepithelial chloride pathways, resulted in 14.8% shorter reaction than during MB-RH stimulation. There were no statistically significant differences between the electric potential values measured during stimulation with amiloride solution, used as inhibitor of transepithelial sodium pathways, and white mulberry in amilorid solution (p=0.485). A short-term application of extract to the colon epithelium is responsible for local and reversible inhibition of chloride ion channels. The extract enhances sodium ion absorption and consequently changes the electrical potential. The effect of white mulberry extract on sodium ion transport may be related to the mechanism of hypoglycaemic activity of mulberry leaves.

Development of Kelvin/Zisman Probe Based Methodology for Detection of Minor Water Leaks in Underground Pipelines

Pipelines are the main means of transportation for liquids such as fresh water. Maintaining the pipelines in a healthy condition is essential to avoid leakage that could affect the economy, environment, sustainability, health and safety. Therefore, valuable water must be well managed and saved by detecting the minor leaks before outrageous losses. The objective of this research is to develop a Kelvin/Zisman probe (KZP) based methodology to detect water leaks in underground supply pipelines. A KZP measures the presence of moisture in soil by assessing the electric potential value (E) in volts that is set-up by the probe. It is designed to detect minor leaks especially in polyvinyl chloride (PVC) and metallic pipes such as steel pipes (ANSI Schedule 40). The developed KZP passes above the ground surface (soil) to take the potential value readings. The reading results confirm the KZP is sensitive to the moisture; so, it can detect water content of soil with 6.7%, 5.6%, and 5.2%, but cannot detect 4.6% or less. Accordingly, the reading results of water contents comply with their R-squared, which are 0.97, 0.96, 0.98, and 0.81, respectively. Furthermore, 6.7%, 5.6%, and 5.2% water content average potential values are 5.6V, 6.2V, and 7.2V, respectively, which are inversely proportional. The proportionality between water content of soil and potential value reading proves the KZP has potential to detect the water leaks.

Improving Prediction of the Potential Distribution Induced by Cylindrical Electrodes within a Homogeneous Rectangular Grid during Irreversible Electroporation

Background: Irreversible electroporation (IRE) is an ablation technique based on the application of short, high-voltage pulses between needle electrodes (diameter: ~1.0 × 10−3 m). A Finite Difference-based software simulating IRE treatment generally uses rectangular grids, yielding discretization issues when modeling cylindrical electrodes and potentially affecting the validity of treatment planning simulations. Aim: Develop an Electric-Potential Estimation (EPE) method for accurate prediction of the electric-potential distribution in the vicinity of cylindrical electrodes. Methods: The electric-potential values in the voxels neighboring the cylindrical electrode voxels were corrected based on analytical solutions derived for coaxial/cylindrical electrodes. Simulations at varying grid resolutions were validated using analytical models. Low-resolution heterogeneous simulations at 2.0 × 10−3 m excluding/including EPE were compared with high-resolution results at 0.25 × 10−3 m. Results: EPE significantly reduced maximal errors compared to analytical results for the electric-potential distributions (26.6–71.8%→0.4%) and for the electrical resistance (30%→1–6%) at 3.0 × 10−3 m voxel-size. EPE significantly improved the mean-deviation (43.1–52.8%→13.0–24.3%) and the calculation-time gain (&gt;15,000×) of low-resolution compared to high-resolution heterogeneous simulations. Conclusions: EPE can accurately predict the potential distribution of neighboring cylindrical electrodes, regardless of size, position, and orientation in a rectangular grid. The simulation time of treatment planning can therefore be shortened by using large voxel-sized models without affecting accuracy of the electric-field distribution, enabling real-time clinical IRE treatment planning.

Electrochemically driven assembly of framework nucleic acids

• The utilization of an electrochemical chip to synthesis DNA nanostructures was firstly developed. • Tetrahedron DNA nanostructures of different sizes (20 bp, 26 bp and 37 bp) and octahedral DNA nanostructure were successfully assembled within 6 min. • The prepared DNA nanostructures exhibit the same structural characteristics and electrochemical performance in comparison to the ones fabricated with thermal annealing method. • The relations between electric potential and pH value were built. Electrochemically controlled synthesis of small molecules, DNA and various nanostructures provided unparalleled advantages to remotely control chemical reactions with high spatial and temporal precision. Although electrochemistry has been reported to actuate the reversible movement of DNA switch or tune the formation of hydrogen bonds in double strand DNA, electrochemically driven formation of DNA nanostructures remains a challenge as the result of their three-dimensional shapes and complex DNA folding pathway. Herein, through integrating a microfabricated chip with three-electrode system, we reported an electrochemical method to control the formation of tetrahedral DNA nanostructures. Using this method, the relation between the potential and solution pH value, and the melting temperature of double strand DNA was built, which facilitates synthesis of the tetrahedron DNA nanostructures in 6 min. Structure characterization of the prepared DNA nanostructures with atomic force microscopy (AFM) proved the physical integrity of the prepared DNA structures. By modifying the prepared DNA structure on the gold electrodes, a DNA nanostructure-based electrochemical biosensor with high sensitivity toward target DNA was fabricated. Based on these advantages, this method holds promise to develop high-throughput electrochemical microdevices capable of in-situ production of DNA nanostructures and the consequent multichannel biosensing.

Electric Potential Value of Microbial Fuel Cell Technology from Chinese Food Restaurant Waste Using Variation of Electrode Pairs

Indonesia's rapid population growth means that power demand will continue to rise year after year. Indonesia's growing population has resulted in an increase in restaurants, including Chinese food restaurants. As the number of restaurants grows, so does the amount of waste produced. Microbial Fuel Cells (MFC) that create electrical energy are one solution to this challenge. The study aimed to explore the utilization of MFC systems for power generation. It measured the performance of MFC in liquid waste in generating electrical value by utilizing a series of electrode types, particularly Aluminum (Al), Copper (Cu), Zinc (Zn), and Lead (Pb), and a blend of the four types of electrodes. The measured electrical value indicated that MFC can produced the high electrical voltage value was the pair of zinc (anode) and copper (cathode) of (0.863 V) and then the highest electric current value is 0.14 mA with electrode Cu and Zn. The maximum power density is 0.00464 W/m2 using a combination of Zn/Cu electrodes and then electrical energy with highest value is 0.75168 J with Zn/Cu.

Dynamic pH and Thermal Analysis of Paper-Based Microchip Electrophoresis.

Paper-based microchip electrophoresis has the potential to bring laboratory electrophoresis tests to the point of need. However, high electric potential and current values induce pH and temperature shifts, which may affect biomolecule electrophoretic mobility thus decrease test reproducibility and accuracy of paper-based microfluidic electrophoresis. We have previously developed a microchip electrophoresis system, HemeChip, which has the capability of providing low-cost, rapid, reproducible, and accurate point-of-care (POC) electrophoresis tests for hemoglobin analysis. Here, we report the methodologies we implemented for characterizing HemeChip system pH and temperature during the development process, including utilizing commercially available universal pH indicator and digital camera pH shift characterization, and infrared camera characterizing temperature shift characterization. The characterization results demonstrated that pH shifts up to 1.1 units, a pH gradient up to 0.11 units/mm, temperature shifts up to 40 °C, and a temperature gradient up to 0.5 °C/mm existed in the system. Finally, we report an acid pre-treatment of the separation media, a cellulose acetate paper, mitigated both pH and temperature shifts and provided a stable environment for reproducible HemeChip hemoglobin electrophoresis separation.

Assessment of the temporal variation of electrical potential and pH of different bleaching agents

IntroductionTooth whitening procedures are under continuous investigation to improve esthetic outcomes and reduce bleaching sensitivity (BS) precipitating from treatments. During the dental bleaching process it is known that the release of free radicals degrades the organic pigment molecules of the tooth and with this an amount of energy is released. Nonetheless, previous studies have never investigated the temporal correlation between of pH and electric potential (EP) generated in this treatment. ObjectivesTherefore, the objective of the present study was to investigate temporal variations of pH and EP associated with three different commercially available bleaching gels and the correlation levels between parameters of interest to provide relevant information regarding the kinetics of oxidation reactions in dental bleaching procedures. MethodsThe study was divided into 3 groups (n = 9) in function of hydrogen peroxide concentration (either 6%, 15% and 35%). The temporal evolution of pH and EP values were determined using a highly-accurate and previously calibrated pH meter at specific time-points (5, 10, 15 and 30 min). ResultsData obtained were submitted to one-way ANOVA of repeated measures with Bonferroni post-test (α = 0.05). The results of the study showed difference in the factor gel concentration (p < 0,0001), time (p < 0,0001) and interaction (gel/time) (p = 0.002) while throughout the intervals evaluated the groups remained relatively stable and without significant difference in the intragroup variation of pH (p < 0.05) and in EDP only with significant difference in the 5 min interval of the 35% concentration. A 2nd order polynomial relationship test showed high correlation levels. ConclusionIt can thus be concluded that there is a negative relationship between EP and pH variation in the different gel concentrations. Clinical significanceThe findings of the present study suggest that bleaching gels of higher concentration may provoke BS that are more intense and durable due to significant electric depolarization of neuronal extensions of pulpal tissues.

In-vivo estimation of tissue electrical conductivities of a rabbit eye for precise simulation of electric field distributions during ocular iontophoresis.

Precise estimation of electrical conductivity of the eyes is important for the accurate analysis of electric field distributions in the eyes during ocular iontophoresis. In this study, we estimated the tissue electrical conductivities of a rabbit eye, which has been widely employed for neuro-ophthalmological experiments, through an in vivo experiment for the first time. Electrical potentials were measured at multiple locations on the skin, while weak currents were transmitted into the skin via two surface electrodes attached to the skin around the eye. A finite element model was constructed to calculate the electric potentials at the measurement locations. The conductivity values of different tissues were then estimated using an optimization procedure to minimize the difference between the measured and calculated electric potentials. The accuracy of the estimated tissue conductivity values of the rabbit eye was validated by comparing the measured and calculated electric potential values for different electrode montages. Further multi-physical analyses of iontophoretic drug delivery to the rabbit eye showed a significant influence of the conductivity profile on the resultant particle distribution. Overall, our results provide an important reference for the tissue electrical conductivity values of the rabbit eye, which could be further utilized for designing new medical devices for delivering electric fields to the eyes, such as transorbital and transscleral electrical stimulations.

Analytical and mathematical simulation for nonlinear stability of scale-dependent magneto-electro-elastic system

By using differential quadrature method (DQM), a numerical investigation was provided for nonlinear stability behavior of magneto-electro-elastic (MEE) cylindrical shells at microscale. It is assumed that the cylindrical shell has been subjected to compressive loads leading to buckling phenomena in geometrically nonlinear regime. The non-uniformity of strain field has been inserted in the formulation for considering the microscale effects. The material properties of the shell are considered to be inhomogeneous with graded distribution. After solving the governing equations using DQM, it is realized that if the nanoscale shell is subjected to electrical and magnetic fields, the post-buckling path may be changed with the value of electrical voltage and magnetic potential. Also, strain gradient effects have remarkable influence on post-buckling curves and critical voltages.

A Transversely Isotropic Magneto-Electro-Elastic Circular Kirchhoff Plate Model Incorporating Microstructure Effect

A non-classical model for transversely isotropic magneto-electro-elastic circular Kirchhoff plates is established based on the extended modified couple stress theory. The Gibbs-type variational principle is used to obtain the governing equations and boundary conditions. To illustrate the newly derived model, the static bending problem of a clamped circular plate subjected to a uniformly distributed constant load is solved numerically by Fourier–Bessel series. The numerical results show that the values of transverse displacement, electric and magnetic potentials predicted by the current model are always smaller than those of the classical model, and the differences are diminishing as the plate thickness increases. In addition, it is shown that the magneto-electro-elastic coupling effect plays an important role in the transverse displacement, electric potential and magnetic potential of the magneto-electro-elastic circular Kirchhoff plates. Furthermore, several reduced specific models are provided for simpler cases.

Assessment of the Temporal Variation of Electrical Potential and pH of Different Bleaching Agents

Introduction: Tooth whitening procedures are under continuous investigation to improve esthetic outcomes and reduce dentin hypersensitivity (DH) precipitating from treatments. Previous studies have never investigated the temporal correlation between of pH and electric potential (EP). Objectives: Therefore, the objective of the present study was to investigate temporal variations of pH and EP associated with three different commercially available bleaching gels and the correlation levels between parameters of interest to provide relevant information regarding the kinetics of oxidation reactions in dental bleaching procedures. Methods: The study was divided into 3 groups (n = 9) in function of hydrogen peroxide concentration (either 6%, 15% and 35%). The temporal evolution of pH and EP values were determined using a highly-accurate and previously calibrated pH meter at specific time-points (5, 10, 15 and 30 min). Results: Data obtained were submitted to one-way ANOVA of repeated measures with Bonferroni post-test (α = 0.05). The results of the study showed difference in the factor gel concentration (p = 0.000), time (p = 0.000) and interaction (gel/time) (p = 0.002) while throughout the intervals evaluated the groups remained relatively stable and without significant difference in the intragroup variation of pH (p < 0.05) and in EDP only with significant difference in the 5 min interval of the 35% concentration. Conclusion: It can thus be concluded that there is a relationship between EP and pH variation in the different gel concentrations. Clinical Significance: The findings of the present study suggest that bleaching gels of higher concentration may precipitate DH that are more intense and durable due to significant electric depolarization of neuronal extensions of pulpal tissues.