Electric Current Source Research Articles

Electromagnetic radiation in a pathologically unirefringent biaxial medium

Electric field and magnetic field phasors are expanded into recently found vector spherical wave functions of a biaxial medium quantified by two anisotropy parameters. The medium is termed biaxial when the two anisotropy parameters are unequal, uniaxial when they are equal, and isotropic when both are unity. Such an expansion has been adopted previously to represent the field phasors inside a scatterer made of the chosen medium, but suspended in free space. In this paper, it is used in computing radiation of electric and magnetic current sources immersed in the chosen medium. The computed fields are valid everywhere, including near-zone and far-zone regions. Duality relations are derived between elementary sources in the chosen medium: point-electric-dipole source and point-magnetic-dipole source. Numerical results on isotropic, uniaxial, and biaxial cases for elementary sources show the evolution of electric field, magnetic field, and directivity pattern in relation to the anisotropy of the medium. In essence, beam shaping including stretching and compression along certain directions is possible upon orienting the dipole's axis with respect to a distinguished axis when the medium is uniaxial, or on varying both anisotropy parameters when the medium is biaxial. As an example for a nonelementary source, line-electric-dipole radiation is considered. With the dipole axis being fixed, steering the main lobes toward the dipole axis, as well as increasing/ decreasing the maximum directivity and beamwidth of main and side lobes is possible by the same aforementioned procedure applied for elementary sources.

Improved Dipole Source Localization from Simultaneous MEG-EEG Data by Combining a Global Optimization Algorithm with a Local Parameter Search: A Brain Phantom Study.

Dipole localization, a fundamental challenge in electromagnetic source imaging, inherently constitutes an optimization problem aimed at solving the inverse problem of electric current source estimation within the human brain. The accuracy of dipole localization algorithms is contingent upon the complexity of the forward model, often referred to as the head model, and the signal-to-noise ratio (SNR) of measurements. In scenarios characterized by low SNR, often corresponding to deep-seated sources, existing optimization techniques struggle to converge to global minima, thereby leading to the localization of dipoles at erroneous positions, far from their true locations. This study presents a novel hybrid algorithm that combines simulated annealing with the traditional quasi-Newton optimization method, tailored to address the inherent limitations of dipole localization under low-SNR conditions. Using a realistic head model for both electroencephalography (EEG) and magnetoencephalography (MEG), it is demonstrated that this novel hybrid algorithm enables significant improvements of up to 45% in dipole localization accuracy compared to the often-used dipole scanning and gradient descent techniques. Localization improvements are not only found for single dipoles but also in two-dipole-source scenarios, where sources are proximal to each other. The novel methodology presented in this work could be useful in various applications of clinical neuroimaging, particularly in cases where recordings are noisy or sources are located deep within the brain.

Масоперенос у пористих електродах свинцево-кислотного акумулятора при розряді

At present, the study of diffusion-controlled processes with volume and heterogeneous chemical reactions plays an important role in various systems, in particular engineering ones, which include electric current sources. Based on familiar equations, this work considers ion exchange processes in the porous spaces of the electrodes of a lead-acid battery during its discharge. Allowance is made for electrochemical processes between the solid electrodes and the electrolyte that fills the porous space. As distinct from the majority of works, allowance is also made for the two-dimensionality of the process, which is due to the geometry of the apparatus and its physical characteristics. An important feature of the work is that in the open zone between the electrodes, the mass transfer is assumed to be convective, whose intensity is much higher than that of the diffusive one in the pores of the electrodes. This allows one to ignore, at least as a first approximation, the resistance of the central zone of the electric cell in the process of ion transfer. This, as one might say, limiting scheme, greatly simplifies the problem of charge transfer through the central zone of the electrochemical cell. It is shown that the electrical conductivity of the solid part of the electrodes plays an important role in the distribution of potentials both in the electrodes themselves and in the porous space. Due to the high electrical conductivity, the negative electrode relative to the positive one operates practically in a one-dimensional mode. It should also be noted that the additional resistance of the separator has a noticeable effect on the operation of the positive electrode, which manifests itself at relatively high currents, when the lack of the charging component becomes noticeable. Another important aspect of the calculation is the determination of the distribution of poorly soluble and poorly conductive lead sulfate (PbSO4), which affects the mass transfer process to a large extent, up to the termination of the discharge. It is shown that at relatively high currents, the formation of the passivating product is concentrated on the outer sides of the electrodes.

Progressive effect of dual-hybridization in friction stir welding by ultrasonic vibration and resistive heating for joining dissimilar material Al6063 aluminium alloy and C26000 copper alloy

In the world of disruptive technology, Al–Cu joints are quite in demand for electric vehicle batteries and other ion battery applications. Fusion welding is the less preferred method due to its many disadvantages; friction stir welding has the potential to become a sustainable process for producing a sound dissimilar Al–Cu joint. A study of multiple hybridization to the Friction Stir Welding (FSW)was made by utilizing two different energy sources of ultrasonic energy and electric current. The improvement is the property by different combination of the hybridization studied for utilizing the multiple hybridization technique to the FSW process for improving the weld efficacy and defects free weld even in case of dissimilar joints. Mechanical properties obtained by varying the process parameters have been studied and compared. Three process parameters have been selected including ultrasonic energy (10 KHz), electric current (75–125 Amps), rpm (400–600 rpm) and transverse tool rate (30–50 mm/min). A remarkable improvement in the mechanical property has been monitored by adding electric current to the UAFSW. Similar optimistic results in the improvement of the property have been found by adding Ultrasonic energy to RHFSW. The comparative study in the mechanical property had been presented to explain the improvement in the weld efficacy.

Impact of DC-DC Converters on the Energy Performance of a Dense Concentrator PV Array under Nonuniform Irradiance and Temperature Profiles

Efficiency losses resulting from electrical mismatching in densely packed photovoltaic arrays present a significant challenge, particularly exacerbated in nonuniformly illuminated receivers and under varying temperatures. Serial configurations are particularly susceptible to radiation nonuniformities, while parallel systems are negatively affected by temperature variations. Various authors have recommended the incorporation of electrical voltage and current sources to mitigate these losses. This study explores different electrical connection configurations utilizing concentrated photovoltaic (CPV) cells and DC-DC electrical current converters. A self-adaptive microfluidic cell matrix cooling system is employed to mitigate thermal dispersion caused by the highly nonuniform illumination profile. The obtained results for each configuration are compared with the total electrical power produced by individual cells, operating under identical radiation and temperature conditions to those of the entire array. The results reveal a noteworthy increase in production across all studied configurations, with the parallel–series arrangement demonstrating the most promising practical utility. This configuration exhibited a remarkable 50.75% increase in power production compared with the standard series connection.

Electroseismic Scholte‐wave analysis: A potential method for estimating shear‐wave velocity structure of shallow‐water seabed sediments

AbstractThe potential application of conducting Scholte‐wave analysis using electroseismic pressure fields excited by an electric current source due to the electrokinetic effect in fluid‐saturated porous seabed sediments is investigated. First, we develop a numerical modelling algorithm by combining the Luco–Apsel–Chen generalized reflection and transmission method with the peak‐trough averaging method to simulate the electroseismic wave fields in stratified fluid/porous media. The modelling results show that the electroseismic pressure signals recorded on the seafloor are mainly composed of evanescent electroseismic waves, and Scholte waves are the dominant wave pattern. Their amplitudes are generally within the order of magnitudes capable of being detected by current seismic instruments. Then, the modified frequency–Bessel transform method is extended to extract the Scholte‐wave dispersion curves from electroseismic pressure fields. Results demonstrate that Scholte‐wave dispersion curves extracted from electroseismic records are superior to those extracted from conventional seismic wave fields excited by an airgun source under the same source–receiver geometry because they contain many overtones and are almost free from the interferences of dispersive guided waves. Furthermore, the Scholte‐wave dispersion inversion results obtained by employing the Levenberg–Marquardt method show that the shear‐wave velocity model inverted by Scholte‐wave dispersion curves extracted from the electroseismic pressure field is more accurate than those obtained by dispersion curves extracted from the seismic wave fields with the guided‐wave removal. The above results indicate that the electroseismic Scholte‐wave analysis method has the potential to evaluate the shear‐wave velocities of shallow‐water seabed sediments.

Electromotive Force of Spontaneously Polarized Semiconductors

Background: Spontaneously polarized finely dispersed semiconductors can be sources of direct electric current, similar to thermoelectric converters. Their power is low due to the low electrical conductivity of the powders. Objective: Theoretical description of the electromotive force of a spontaneously polarized homogeneous semiconductor film with ionized donor centers uniformly distributed over its two surfaces and free electrons in the volume. Establishment of technical characteristics and competitive advantages of using a film as a current source converts the received energy (heat or light) into the work of an electric field. Methods: The theory of semiconductors and the laws of thermodynamics are used. Results: Analytical expressions are obtained that describe the electronic processes in a metal-semiconductor-metal three-layer film and the technical characteristics of its use as a current source. Estimates are given on the example of a silicon film with arsenic-doped surfaces. Conclusion: The universal principles for creating homogeneous solids of macroscopic dimensions are substantiated, with the efficiency of converting heat into the work of an electric field, which is significantly (by an order of magnitude) higher than the efficiency of materials used to create thermo-EMF sources. The heat absorbed by the metal-semiconductor-metal three-layer film serves as an energy source for a direct current in a closed circuit generated by this structure with an efficiency of 100%. The power of the current source 10 - 105 W/m depends on the received heat flow. A semiconductor film with a built-in electric field is an analogue of a p - n junction and does not have its drawbacks.

PEMBERDAYAAN KELOMPOK TANI TERNAK DALAM PENERAPAN TEKNOLOGI MESIN PENCACAH RUMPUT ALTERNATIF UNTUK PAKAN TERNAK KAMBING DI DESA KOLAM KEC. PERCUT SEI TUAN

One of the potential livestock commodities to be developed is goats. A number of problems faced by goat breeders include seed quality, feed supply, disease prevention, market expansion to increase production. However, the main problem of discussion is the availability of animal feed. Currently goat breeders are still experiencing a problem in the supply of animal feed as a source of protein. Breeders must provide grass in sufficient quantities to be chopped as livestock feed. Most breeders still use the conventional grass chopping process. Farmers in the Pond Village area still use sickles to get grass which has to provide large amounts of grass as the number of goats also increases, therefore it takes more time and effort. The solution to solving the problems faced is to approach partners so that alternative grass chopping technology can be accepted and implemented. With the application of alternative grass chopping machines, smaller pieces of grass are obtained to be given as animal feed so that it is easier for livestock to digest the food. As the prime mover of this grass chopper is an electric motor and a gasoline engine. If the location is available a source of electric current can use an electric motor dynamo. If the conditions where the livestock is far from the reach of electricity can use a gasoline engine. Alternative grass chopper with consequences can increase livestock feed production capacity. Transferring the function of using a scythe as a grass chopping tool to chopping grass using a machine will ensure a quick time and an increase in production capacity which has been proven to work in the Kesuma cattle farming group. The grass chopper application is well supported/welcomed by the farmer group members, it is hoped that the farmer group residents will continue to use this chopper application.

Creation of optical chains with prescribed characteristics

We report a non-iterative method to create an arbitrarily spatially-orientated optical chain with prescribed characteristics through the use of antenna radiation theory and time reversal methodology. A pair of antennas consisting of an electric current line source (ELS) and a magnetic current line source (MLS) are employed to yield the required incident field pattern for focusing system. Numerical results demonstrate that the direction of the generated optical chain is consistent with the orientation of the combined antennas, and the length of the optical chain is approximately equal to the length of the combined antennas, and the amount, position and spacing of the dark hollow spots are determined by the length of the combined antenna and the amplitude periodic coefficient of the ELS. The generated optical chains may find potential applications in multi-points optical capture and particle delivery along prescribed directions.

Design of Digital Solar Water Pump Using Microcontroller ATmega 32

This paper focuses on the application of solar energy along with microcontrollers to design and run a motor to pump water from various sources. The solar water pump is one of the applications or appliance that perform task with the use of solar radiation. The solar water pump consists of solar PV array, solar pump, inverter, AC water pumping device etc. Solar energy radiation is converted in electrical current or power source which is then used to run a pump and draw water directly from ground, wells, rivers, lakes etc. In this paper, the relationship between flow rate of the water and luminous intensity of the solar irradiance is studied and the data are linearly fitted to find out the correlation between these parameters. Also the study about efficiency of the solar powered water pump shows that the operation of this type of pumping system is quite efficient than other types of fossil fuel engines like diesel, petrol, kerosene etc. in long run. The use of Arduino Uno, flow sensor, LDR sensors in the solar powered water pump helps to analyze the relation between these parameters and know the conditions favorable for excess supply of water in short time efficiently. These solar powered devices are the future of clean and green future of this world. Thus it is not only necessary but also compulsory to enhance the usage of solar energy throughout the globe.

A Compact In-Band Full Duplexing Antenna With Quasi-Isotropic Radiation Pattern for IoT-Based Smart Home and Intravehicle Wireless Communication Applications

An innovative planner in-band full duplexing antenna with quasi-isotropic radiation pattern is proposed for the first time in this article for Internet of Things (IoT)-based smart home and intravehicle wireless communication applications. The antenna consists of a radiating patch, a fence-strip resonator (FSR), and a ground plane with the same size as the radiating patch. The fence in the FSR located in the center plane of the patch has the function of simultaneously acting as a part of the resonator to improve the isolation between the transmitting port and the receiving port and as an electric current source for radiating a quasi-isotropic pattern. When the FSR resonates, a quasi-TEM field is formed mainly concentrated in the half of the antenna. The magnetic field generates surface electric current on the fence, and the electric field generates surface magnetic current on the open-ended aperture. The surface electric current and the surface magnetic current are not only orthogonal to each other but also have a phase difference of 90°. Theoretical analysis is provided to clarify the mechanism by which such a combination of radiation sources can generate a quasi-isotropic radiation pattern. To verify the proposed concepts, a high port isolation full duplexing antenna with quasi-isotropic radiation pattern is designed and fabricated, which has a compact size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.28\,\,\lambda _{0} \times 0.28 \lambda _{0}\times 0.042 {\lambda }_{0}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\lambda }_{0}$ </tex-math></inline-formula> is the free space wavelength at 2.45 GHz). A measured isolation greater than 24 dB is achieved over the operating band from 2.42 to 2.50 GHz. The measurement results also show that the gain variation (GV) of port1 and port2 on the entire virtual radiation spherical surface is less than 6.88 and 6.74 dB, respectively.

Manufacturing of IOT-Based Industrial Wastewater pH and TSS Monitoring Instruments Using RUT 955

According to data from the Environment Ministry of the Republic of Indonesia, 59 percent of Indonesian rivers are severely Polluted. The pollutant is due to many people's and industry's behavior of discharging waste directly into the river. This liquid waste contains solids and chemical compounds that affect river water's acidity (pH). Their pollutant does not meet the Government Regulation of the Republic of Indonesia Number 101/2014. Research has been carried out to manufacture an IoT-based sparing monitoring system device using RUT955 to measure the pH and TSS of industrial wastewater in remote areas. This sparring system uses two sources of electric current: PLN and the sun. Solar electricity stored in the battery is used to overcome the problem of breaking the electricity supply from PLN. The device made has been successfully connected to the internet using the webhook.site platform. Acquisition data storage is carried out using the google spreadsheet platform. The pH and TSS data measured by the sensor sent by RUT955 can be received and displayed on the internet platform. The measurement results that the sensor has carried out need to be calibrated so that the data sent is accurate.

Bed-Detection Sensitivity Employing 1D Response to an Electric Dipole Source in Multilayer Anisotropic Formations

Electric and magnetic field responses originating from a primary electric current source have been analytically derived, explored, and employed to explore and detect electrical anomalies due to the presence of a bed boundary in a two-layer model, using the controlled source electromagnetic method. However, previous works on the subject demand in-depth knowledge of mathematics, which could become an obstacle for the practitioner looking to immerse into the realm of induction logging and who needs a straightforward approach to develop their algorithms. Consequently, we introduce the analytical expressions for electric and magnetic field responses to an electric current dipole source arbitrarily oriented in one-dimension (1D) transversely isotropic media. In addition, we apply these equations to examine both electric and magnetic field responses to a distant resistive anomaly from electric transverse electric dipole transmitters. Our analysis shows that magnetic field responses are significantly more sensitive to the anomaly ahead of the tool for a vertical or a horizontal borehole. While the coplanar electric field measurements with conventional electric resistivity tools are known to be sensitive to the resistivity anomaly around the tool, the axial magnetic field measurement using the transverse electric dipole transmitter and the transverse magnetic field measurement using an axial electric dipole transmitter are significantly more sensitive to the anomaly around the tool than any electric field measurements. This deep-looking capability is achieved with a relatively short source-receiver spacing of 10 m. Based on the increased deep-looking capability, we encourage the use of magnetic components from our generalized geosteering tool based on electric dipole sources because it can potentially flag anomalies at a distance 60% further in comparison to the sensitivity of electric measurements.

Tornados and cyclones driven by Magneto-hydrodynamic forces

A numerical analysis is carried out to explore the variety of flow structures induced inside a conducting fluid emerging from the interaction of an electric current source with an external axial magnetic field. Results are obtained for Shercliff (S) numbers up to 1010 and Hartmann (Ha) numbers up to 115, for a single magnetic Prandtl number of Pm=8.6× 10−7. Depending on these numbers, very different swirling flow patterns are predicted. Transitions seem to be solely controlled by two dimensionless ratios Γ=Ha/(PmS)1/2 and N=Ha6Pm/S.For low Γ, vortex-breakdown, tornados and cyclones are obtained. These MHD tornados are found to be very similar in structure to atmospheric tornados. A slight increase in Γ results in the transformation of the tornado into a cyclone which rotates at relatively constant angular velocity. Surprisingly for further increase in Ha, the cyclone is restructured into an inverted tornado. The induced currents are found to be at the origin of this phenomenon. For large N, a Hartmann swirling flow occurs which is associated with almost vertical electric current lines. In this regime, both poloidal and azimuthal flows are damped, and remain mainly present in the forcing region at the edge of the electric current column. These results may be of relevance for the understanding of flow structures in the atmosphere, in aluminum reduction cells, electro-metallurgical processes, and in liquid metal batteries.

Model predictive control of switching continuous‐time systems with stochastic jumps: Application to an electric current source

This paper proposes an extension of the model predictive control framework for switching continuous-time linear systems. The switching times follow a stochastic process with limited statistical information. At each switching time, the controller knows the system state, but it is blind with respect to the switching continuous-time subsystems. In this setting, the paper's main contribution is to show how to compute the model predictive control gain. The paper also illustrates the implications of our approach for applications. The approach was used in practice to control an electric current source that supplied a switching load. The experimental data support the usefulness of our approach.

Simultaneous inversion of spectral IP data with frequency constraints

Spectral-induced polarization (SIP) measures the apparent complex resistivities (CRs) of electrical current sources at frequencies of less than 10 kHz. The measured apparent CRs are usually inverted to recover the intrinsic subsurface CRs, which depend on the source frequencies. The Cole-Cole (CC) model is commonly used to describe the dispersion characteristics of the intrinsic CRs; electrical resistivity, chargeability, and the time and relaxation constants can be derived using this model. For quantitative estimation of these parameters, a reliable inversion method for multifrequency SIP datasets is required. Conventionally, SIP data at each frequency are independently and sequentially inverted. This does not consider the relationships between SIP datasets of different frequencies. To consider such relationships, here, we simultaneously invert multi-frequency SIP datasets by introducing frequency-smoothness constraints between adjacent frequencies. We numerically verified the utility of the approach in terms of both amplitude and phase recovery; the method yielded more reliable relaxation models (e.g., CC models) than conventional inversion. For field verification, the method was applied to SIP data of several frequencies obtained in South Korea.

Dimension and Sampling of the Near-Field and Its Intensity Over Curves

The paper addresses the question of efficiently sampling the near field and its intensity over an arbitrary curved line. It aims at finding the minimum number of measurements and their position for discretizing the near field and its square amplitude without loss of information and follows a common approach for both the radiation operator and the correspondent lifting operator. A scalar geometry is examined for both electric and magnetic current sources. At first, the singular values of the radiation / lifting operator are evaluated by an asymptotic approach and a change of variables which lead to an operator with a widely investigated spectrum. As the number of relevant singular values is available in closed form, the dimensions of the near field and its intensity over the curve are found. Next, starting from a sampling expansion of the pertinent left singular functions, a non-redundant sampling representation of the near field and its square amplitude is provided. Some numerical results confirm the analysis. The results may be of great interest especially in antenna testing by near field data (both standard and phaseless) with an unconventional field scanning system as, for instance, an UAV mounted probe.

MAKING PROTOTYPE OF ELECTRO PLATING EQUIPMENT FOR HOME INDUSTRYOME INDUSTRI

Corrosion is an electrochemical reaction process that is natural and takes place by itself, corrosion cannot be prevented or stopped but can only be controlled using the Electro Plating method. Electroplating is a process that produces a thin layer of metal on top of another metal surface by electrolysis or electroplating using direct current (DC) and chemical solutions (electrolytes). The process of giving this protective layer aims to protect the metal from corrosion, in this study, will make a prototype electro plating tool for small industry or Home Industry, the completeness of the components needed to make a prototype electro plating tool is an AC transformer matic 30-50 A 12V, ampere meter, volt meter, fuse and switch, then nickel solution serves to provide strength, metal resistance from rust and chrome solution serves to provide resistance to corrosion and gives a glossy white color so it looks better, to produce a strong coating. With the occurrence of the anode, cathode, and electrolyte solution which are used entirely as related to coating materials, especially metals are illustrated as, the cathode can be interpreted as the workpiece to be coated, connected to the negative pole of the electric current source and the electrolyte in the form of a solution whose molecules can be dissolved. in water and decomposes into positively or negatively charged particles and the deposition in the process is due to the presence of ions in the electrolyte and will settle on the cathode and the process of coating the metal occursPlease write your abstract in English version here.

Design of wideband end‐fire composite microstrip‐monopole antenna

This article introduces a wideband composite antenna with end-fire radiation. The structure is achieved by uniting a center-fed microstrip shorted patch and a parasitical monopole. The monopole is vertical to the substrate and work as an electric current source. Because the loaded monopole breaks the symmetry of the center-fed microstrip antenna, the original patch antenna can work as in-phase equivalent magnetic current sources radiation. Then complementary sources are generated by orthometric magnetic current source and electric current source. The typical unidirectional radiation capacity has a good endfire beam. The loaded monopole adds a resonant mode to the original microstrip antenna, which makes the composite microstrip-monopole antenna to exhibit an enhanced bandwidth of 26.9% and an average gain of 7.5 dBi. The complementary sources radiation mechanism can generate special unidirectional radiation patterns in a compact space, so this antenna type is an excellent candidate for array applications. The prototype's planar size is only 0.36λ0 × 0.39λ0 (λ0 is the free space wavelength in center frequency). The eight elements phased array with the proposed antenna show perfect simulated scanning performance.

Ecological and Legal Problems of Electrification of Motor Vehicles

The article is focused on studying the state policy, legislation and practice of its application in Ukraine regarding the use of electrified motor vehicles – battery vehicles that run on chemical sources of electric current. The purpose of the work is to determine the legal mechanisms to prevent the negative impact on the environment from the electrification of motor vehicles.&#x0D; The methodological basis of the research included: comparative and legal method, which was used to study the requirements of EU and Ukrainian legislation; the method of system analysis allowed us to reveal the legal mechanisms of regulating the use of car batteries and the subsequent treatment of unusable power batteries of electric vehicles.&#x0D; The result of the research was the justification of the need to: update the legislation of Ukraine on chemical sources of electric current, in the process of which one should take into account the expansion of such sources, increasing their number and, most importantly, the total mass; creation and introduction of a system of accounting for operations on supply and utilization of batteries of electric vehicles with the obligation of suppliers of such components to create an infrastructure for collection and subsequent transfer for disposal to manufacturers of batteries unfit for further operation; establishment of the presumption of environmental pollution by the owner of the electric vehicle in case of purchasing the element or the whole battery without transferring the fulfilled or damaged battery to utilization.&#x0D; The results of the research can be used in law-enforcement practice to prevent the negative impact on the environment of by unusable power batteries of electric vehicles, as well as in lawmaking to improve legal mechanisms of preventing mass accumulation of used chemical sources of electric current in Ukraine.