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Shunt resistance R sh is a critical parameter for photovoltaic cells designed for low light indoor applications because it negatively affects the open circuit voltage, fill factor, and conversion efficiency. Standard CIGS cells are known to have low R sh and are, therefore, unpromising candidates for indoor energy sources. In this paper, we extend the original work of Virtuani et al. by determining the electrical specifications of many CIGS cells with copper contents [Cu]/([Ga]+[In]) as low as 0.33 and gallium contents between 0.28 and 0.81. First, IV data are fitted by a standard single-diode electrical circuit model for each illumination, resulting in light-dependent parameters. Then, we use a procedure based on a single dataset of electrical variables, i.e., independent of light, corrected by the experimental collection function, which captures light-dependent physical mechanisms. In this way, we are able to correctly reproduce the illuminance dependence of the electrical response of the PV cell over three orders of magnitude, in particular with a fixed value of the shunt resistance. The highest R sh is obtained with a low copper composition of 0.5 , regardless of the gallium composition. [ABSTRACT FROM AUTHOR]

We propose a novel hybrid acoustic metamaterial that can achieve broadband sound insulation below 452 Hz and almost perfect sound absorption at 864 Hz. The metastructure was fabricated using additive manufacturing. Finite element method simulations were used to study the acoustic properties of the fabricated metamaterials. An equivalent electrical circuit was built using an electro-acoustic analogy to evaluate the sound absorption coefficient. The unique design of this meta-structure possesses two resonant frequencies. Low-frequency sound insulation is found due to the effective negative density at frequencies lower than the cutoff frequency of the elastic membrane. In contrast, a negative effective bulk modulus is the reason behind the broadband sound absorption. The theoretical and simulation results were validated through experiments. Experiments carried out showed an overall average sound transmission loss of 26.31 dB between 50 and 1600 Hz and 24.72 dB in the low-frequency zone (<400 Hz). Furthermore, over 69% of the sound intensity is absorbed in the 500–1000 Hz frequency range. The designed meta-structure exhibits broadband effective negative density below 452 Hz and effective negative bulk modulus from 864 to 1220 Hz. The design specifies a sample thickness of 3.8 cm, corresponding to a subwavelength thickness of approximately λ/10. As a result, the developed meta-structure can potentially be employed for sound insulation and absorption at low frequencies in the aerospace and automotive industries and in-room acoustic applications. [ABSTRACT FROM AUTHOR]

The paper considers tasks related to the search for the parameters of smart-systems with piezoelectric elements, to the electroded surfaces to which elements of electrical circuits are connected. The required parameters should provide the maximum damping properties of the simulated systems at free and steady-state forced vibrations. The paper presents the results of calculations of smart-system parameters providing maximum damping properties at free and forced vibrations, which were performed in the framework of continuum and discrete mechanics models. The results demonstrate variants for which the parameters found based on continuum mechanics models provide higher vibration damping rates. [ABSTRACT FROM AUTHOR]

Background: Electric circuit concepts in physics are abstract in nature and students find it difficult to comprehend. Purpose: This study was designed to compare the impact of three different strategies: simulation, hands-on and a combined strategy in enhancing conceptual understanding on electric circuit for class X students. Design: A mixed method with quasi-experimental research design was used. Sample: A total of 71 students participated in three comparative groups. Method: The comparative group 1 was taught using simulation, comparative group 2 with a combined strategy, and a comparative group 3 with hands-on activities. The quantitative data were collected through standard norm-referenced pre- and post-test from all the comparative groups and the qualitative data was collected through semi-structured focused-group interview. Result: The study concluded that a combined strategy was more effective in enhancing conceptual understanding of electric circuit concepts in comparison to the use of simulation and hands-on strategies. This is because the participants were able to master the gaps of their learning from one strategy by the other strategy. However, there was a mixed opinion between the simulation and hands-on strategy. The post-test result revealed that simulation was more effective, whereas the interview revealed that hands-on strategy was more effective for students to understand the electric circuit concept. Nevertheless, the study recommends the future researchers to test and verify the effectiveness of this strategy by implementing it in teaching higher electric circuit concepts like resistivity, Kirchoff's laws and other physics topics. [ABSTRACT FROM AUTHOR]

Summary: Multi‐module isolated converters (MMICs) find extensive applications in various DC–DC applications owing to their exceptional features of galvanic isolation, bidirectional power flow, high‐power density, and enhanced efficiency. However, voltage and current sharing among the converter modules are the most significant issues in MMICs. This paper proposes multiport integrated‐magnetics transformers (MpIMTs) which address the input–output DC‐link voltage imbalances within an ISOS converter. The proposed transformers ensure the input voltage sharing (IVS) and output voltage sharing (OVS) through balancing windings within their structures, thus substitutes the complicated active control scheme with the balancing winding. Besides, the input side and output side modules are decoupled from each other; thus, the impact of parameters variation and intermodule energy transfer during a transient of one side does not reflect to the other side. These properties are achieved by proposing a custom‐designed core and an off the shelf available U‐core assembled MpIMTs. The magnetic and electrical equivalent circuit along with the design criteria of the balancing winding are also presented. Furthermore, the paper includes the comparative analysis of the proposed transformers which reveals that while the U‐core MpIMT offers simplified construction, it comes at the expense of slightly reduced efficiency compared with the custom‐designed MpIMT. Finally, the proposed U‐core MpIMT is validated through a laboratory prototype. [ABSTRACT FROM AUTHOR]

A vanadium redox flow battery (VRFB) is an intermittent energy storage device that is primarily used to store and manage energy produced using sustainable sources like solar and wind. In this work, we study the modeling and operation of a single-cell VRFB whose active cell area is 25 cm 2 . Initially, we operate the cell at multiple flow rates by varying the current densities to study the behavior of the cell at different flow rates. Based on the observations from this experimental study, a suitable flow rate is selected such that the power density of the cell is maximized. In order to accurately represent the dynamic behavior of the VRFB, an electrical equivalent circuit model (ECM) is introduced from existing models documented in the literature based on simplicity and accuracy based on the RMS value of the error in the output voltage. Additionally, the pulse charge–discharge test was conducted on the VRFB under the specified operating flow rate. The data obtained from this test were utilized to estimate the parameters of the dynamical equivalent circuit model. In our study, we have proposed a modified state of charge (SOC) equation considering the self-discharge current loss through a parallel resistor while identifying the SOC–OCV relationship. Analysis of VRFB charge–discharge data is employed to validate the ECM, and the accuracy of the model is determined based on RMSE between the terminal voltage predicted by the model and the actual experimental setup. The resulting RMSE is found to be 19.4 mV, describing the model accuracy of 98.73%. [ABSTRACT FROM AUTHOR]

This paper investigates the simulation of brain chaos dynamics using a combination of the Chua circuit and diode tunnel mechanisms, aiming to examine chaotic behavior in brain networks. Leveraging the inherent chaotic properties of the Chua circuit, Fitzhugh-Nagumo (FHN) function and the nonlinear characteristics of diode tunneling, our model offers a platform to mimic the intricate synaptic interactions observed in the brain. By subjecting the model to various stimuli and perturbations, we analyze the emergence and evolution of chaotic patterns, shedding light on the underlying mechanisms of cerebral chaos. Through numerical simulations and experimental validation, we demonstrate the effectiveness of our approach in replicating key features of brain chaos and highlight its potential implications for understanding neurological disorders and cognitive processes. This research contributes to the broader effort of leveraging computational models to explore the complex dynamics of the brain and their implications for neuroscience and microengineering. [ABSTRACT FROM AUTHOR]

Blind and visually impaired people (VIP) face many challenges in writing as they usually use traditional tools such as Slate and Stylus or expensive typewriters as Perkins Brailler, often causing accessibility and affordability issues. This article introduces a novel portable, cost-effective device that helps VIP how to write by utilizing a deep-learning model to detect a Braille cell. Using deep learning instead of electrical circuits can reduce costs and enable a mobile app to act as a virtual teacher for blind users. The app could suggest sentences for the user to write and check their work, providing an independent learning platform. This feature is difficult to implement when using electronic circuits. A portable device generates Braille character cells using lightemitting diode (LED) arrays instead of Braille holes. A smartphone camera captures the image, which is then processed by a deep learning model to detect the Braille and convert it to English text. This article provides a new dataset for custom-Braille character cells. Moreover, applying a transfer learning technique on the mobile network version 2 (MobileNetv2) model offers a basis for the development of a comprehensive mobile application. The accuracy based on the model reached 97%. [ABSTRACT FROM AUTHOR]

A substantial interest in inductive power transfer (IPT) is due to its straight forwardness and dependability in charging electric vehicle (EV) batteries for researchers. The mutual inductance (MI) plays a critical role in the IPT system as it enables efficient power transfer. Therefore, it is imperative to examine the MI between the two coils that are connected through inductive coupling. This work investigates the MI and efficiency of connected coils in interoperable conditions. The transmitter coil is arranged in the shape of a square (TxS), whereas the reception coil is arranged in the shape of a circle (RxC). A concise and user‐friendly collection of design guidelines for S‐S compensated resonant inductive power transfer (SS‐RIPT) systems the design concepts efficiently mitigate the possibility of systematically and unambiguously setting the specifications for a given load profile. A 3.6‐kW setup has been constructed and validated by finite element analysis and experimental testing, following the design specifications. The availability of suitable testing equipment in the laboratory influenced the choice of a resonance frequency and output voltage for a 3.6 kW system. [ABSTRACT FROM AUTHOR]

In the realm of wireless power transfer, considering misalignment between transmitting and receiving coils is imperative. Traditional wireless power transfer systems experience a significant decrease in output power when the coupling coefficient fluctuates. This paper proposes a reconfigurable dual‐frequency series–series (SS) topology with primary side inductive detuned and secondary side with full resonance. The proposed topology operates at two frequencies and can be transformed into two different SS topologies at each frequency. This allows the system to switch between the two SS topologies when a large misalignment occurs, thereby achieving a more stable output power level. Furthermore, a comprehensive parameter design flowchart for the proposed topology is presented, and the parameters for a 400 W prototype are designed and implemented. The prototype is tested to evaluate the performance of the topology. The frequency response analysis of the prototype validates the effectiveness of the parameter design method. The test results show that the topology can maintain output power fluctuations within 23% of the maximum power for misalignment ranging from k = 0.13 to k = 0.46. Additionally, the system maintains an efficiency of at least 80% across the entire output power flat range, peaking at a maximum efficiency of 91%. [ABSTRACT FROM AUTHOR]

Recently, topolectrical circuits (TECs) boom in studying the topological states of matter. The resemblance between circuit Laplacians and tight-binding models in condensed matter physics allows for the exploration of exotic topological phases on the circuit platform. In this review, we begin by presenting the basic equations for the circuit elements and units, along with the fundamentals and experimental methods for TECs. Subsequently, we retrospect the main literature in this field, encompassing the circuit realization of (higher-order) topological insulators and semimetals. Due to the abundant electrical elements and flexible connections, many unconventional topological states like the non-Hermitian, nonlinear, non-Abelian, non-periodic, non-Euclidean, and higher-dimensional topological states that are challenging to observe in conventional condensed matter physics, have been observed in circuits and summarized in this review. Furthermore, we show the capability of electrical circuits for exploring the physical phenomena in other systems, such as photonic and magnetic ones. Importantly, we highlight TEC systems are convenient for manufacture and miniaturization because of their compatibility with the traditional integrated circuits. Finally, we prospect the future directions in this exciting field, and connect the emerging TECs with the development of topology physics, (meta)material designs, and device applications. [ABSTRACT FROM AUTHOR]

A regression model based on graph neural network, tailored for electric circuit dynamics prediction is introduced, providing converter performance predictions on converter circuit level and internal parameter variations. Regardless of the number of components or connections present in a converter circuit, the proposed model can be readily scaled to incorporate different converter circuit topologies. Moreover, the model can be used to analyse converter circuits with any number of circuit components and any control parameters variation. To enable the use of machine learning methods and applications, all physical and switching circuit properties such as converter circuits operating in continuous conduction mode or discontinuous conduction mode are accurately mapped to graph representation. Three of the most common converters (Buck, Boost, and Buck-boost) are used as example circuits applied to model and the target is to predict the gain and current ripples in inductor. The model achieves 99.51% on the R 2 measure and a mean square error of 0.0263. [ABSTRACT FROM AUTHOR]

Conventional approaches to creating high‐resolution electric circuits face challenges such as the requirement for skilled personnel and expensive equipment. In response, we propose an innovative strategy that leverages a photochemically modified porous polymer skeleton for in‐situ circuit fabrication. By developing maskless surface energy manipulation that guides PEDOT:PSS‐based conductive ink deposition, electric circuits with high precision, density, stability and adaptability are effortlessly engineered within or atop the porous skeleton, enabling transitions between 2D and 3D circuit configurations. This process simplifies prototyping while significantly reducing costs and maintaining efficiency, promising advancements across various technological sectors. [ABSTRACT FROM AUTHOR]

This article focuses on the study of local truncation errors (LTEs) in the Network Simulation Method (NSM), specifically when using the trapezoidal method and Gear's methods. The NSM, which represents differential equations through electrical circuit elements, offers advantages in solving nonlinear dynamic systems such as the van der Pol equation. The analysis compares the performance of these numerical methods in terms of their stability and error minimization, with particular emphasis on LTE. By leveraging circuit-based techniques prior to numerical application, the NSM improves convergence. This study evaluates the impact of step size on LTE and highlights the trade-offs between accuracy and computational cost when using the trapezoidal and Gear methods. [ABSTRACT FROM AUTHOR]

High-efficiency microcalorimeter arrays are required as imaging spectroscopy for X-ray microscopy in general and for astrophysics. We have developed in-house an array of Transition Edge Sensor (TES) X-ray microcalorimeters with mushroom-type absorbers which have a large area of 260 μ m square with multiple support stems. Insufficient thermal conductivity may degrade the energy resolution. We construct a 3D FEM simulation with thermal conduction and electric feedback circuit of TES. Estimated physical parameters were incorporated into the simulation to reproduce the measured pulse waveforms. As a result, the effect of the large absorber on the degradation of energy resolution was small for the mushroom-type absorber TES calorimeter. [ABSTRACT FROM AUTHOR]

Electrical circuits are present in a variety of technologies, making their design an important part of computer aided engineering. The growing number of parameters that affect the final design leads to a need for new approaches to quantify their impact. Machine learning may play a key role in this regard; however, current approaches often make suboptimal use of existing knowledge about the system at hand. In terms of circuits, their description via modified nodal analysis is well‐understood. This particular formulation leads to systems of differential‐algebraic equations (DAEs), which bring with them a number of peculiarities, for example, hidden constraints that the solution needs to fulfill. We use the recently introduced dissection index that can decouple a given system of DAEs into ordinary differential equations, only depending on differential variables, and purely algebraic equations, that describe the relations between differential and algebraic variables. The idea is to then only learn the differential variables and reconstruct the algebraic ones using the relations from the decoupling. This approach guarantees that the algebraic constraints are fulfilled up to the accuracy of the nonlinear system solver, and it may also reduce the learning effort as only the differential variables need to be learned. [ABSTRACT FROM AUTHOR]

Von Neumann architecture requires information to be encoded as numerical values. For that reason, artificial neural networks running on computers require the data coming from sensors to be discretized. Other network architectures that more closely mimic biological neural networks (e.g., spiking neural networks) can be simulated on von Neumann architecture, but more important, they can also be executed on dedicated electrical circuits having orders of magnitude less power consumption. Unfortunately, input signal conditioning and encoding are usually not supported by such circuits, so a separate module consisting of an analog-to-digital converter, encoder, and transmitter is required. The aim of this article is to propose a sensor architecture, the output signal of which can be directly connected to the input of a spiking neural network. We demonstrate that the output signal is a valid spike source for the Izhikevich model neurons, ensuring the proper operation of a number of neurocomputational features. The advantages are clear: much lower power consumption, smaller area, and a less complex electronic circuit. The main disadvantage is that sensor characteristics somehow limit the parameters of applicable spiking neurons. The proposed architecture is illustrated by a case study involving a capacitive pressure sensor circuit, which is compatible with most of the neurocomputational properties of the Izhikevich neuron model. The sensor itself is characterized by very low power consumption: it draws only 3.49 μ A at 3.3 V. [ABSTRACT FROM AUTHOR]

An unprecedented thunderstorm ground enhancement (TGE) event was recorded on May 23, 2023, at Aragats Mountain, the highest peak in Armenia. This event showcased a maximum flux intensity surpassing 3 million particles per minute per square meter for energies above 0.4 MeV. Distinctly, the fluence of the event was measured at approximately ≈700 particles/cm2. The comprehensive instrumentation at the Aragats research station, including a suite of spectrometers and detectors, enabled precise cross-correlation of measurements. The electron flux at energies exceeding 10 MeV was observed at roughly ≈55,000 particles per minute per square meter. Additional measurements, including cloud base heights and corona discharge detections, validated the intensity of the electric field, reaching approximately 2.1 kV/cm at elevations 50–100 m above ground level. Our observations confirm that TGE is a universal and significant atmospheric event, contributing a substantial flux of high-energy electrons to the global electrical circuit. Integrating such TGE phenomena into Earth's numerical models is imperative, considering their impact on aviation and aerospace operation safety. [ABSTRACT FROM AUTHOR]

This study investigates the application of a Wheatstone bridge, specifically through the utilization of a meter bridge constructed on chart paper using pencil graphite. Employing the Wheatstone bridge principle, this study aims to achieve precise measurements of an unknown resistance. Results indicate an error margin between measured and calculated values of less than 10%, highlighting the efficiency and accuracy of this approach. The demonstrated effectiveness of the meter bridge serves as an educational resource, particularly beneficial for K-12 students, providing practical understanding and hands-on experience with the meter bridge concept. This research contributes to enhancing STEAM education by offering a tangible and accessible tool for teaching electrical circuit principles. [ABSTRACT FROM AUTHOR]

In nature, wind can transport objects of diverse shapes and materials over long distances spanning meters or beyond. In contrast, most noncontact manipulation methods are effective only over centimeter‐scale distances and require the manipulated objects to have specific magnetic, electrical, or other material properties and shapes. Herein, a meter‐scale distance manipulation method is presented for controlling the motion of objects of diverse shapes and materials on a plane surface using a jet‐induced airflow field. The airflow field is varied by controlling the direction of a single air jet projected onto a surface based on the positions of objects to steer the objects to follow desired trajectories up to 2.7 m away. A wide variety of objects can be automatically manipulated, from regularly shaped polystyrene hemispheres and sticks to irregularly shaped cotton wads and face masks as well as deformable tissue papers and plastic bags. The method is also robust, effectively manipulating objects under challenging conditions, e.g., external airflow disturbances, surface obstacles, and air–water interface. Finally, three application cases are demonstrated: collecting diverse objects into a target receptacle, hooking and retrieving heavy objects with a tethered mobile agent, and closing an electrical circuit with an untethered soft agent. [ABSTRACT FROM AUTHOR]

This paper focuses on the module "Fundamentals of Electrical Engineering," in which students from different engineering disciplines often face difficulties. Despite efforts to enhance the course through digital media, the formation of study groups, and adjusted lecture and exercise materials, there is still a high failure rate in the subject, leading to potential student dropouts. The primary goal is to analyze students' challenges in solving electrical engineering problems to evaluate their grasp of the fundamentals of electrical engineering and identify varying levels of competence. The findings are based on a cross-sectional study conducted at the conclusion of a university course in Germany, involving 196 students. Through item response theory (IRT) analyses, it was determined that the assessment items demonstrated satisfactory fit values. The proficiency model delineates four levels, with only 8.2% of students achieving the highest level. At this stage, students can tackle more intricate problems using circuit analysis techniques. However, a notable portion of students (40.3%) lack a basic understanding of electrical circuits, placing them at the lowest level. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of robust coordination control based on interval observers for multi‐agent systems in the presence of input saturation and disturbances. Firstly, in the scenario where the system state is not directly measurable, two types of interval observers are, respectively, constructed by resorting to the upper and lower bounds on external perturbances as well as the output information. Secondly, a parametric Lyapunov equation‐based low‐gain feedback control method is proposed to guarantee semiglobal bounded consensus. In contrast to the conventional approach based on parametric algebraic Riccati equations, the proposed method offers the advantage of allowing the parameters to be determined in advance. Finally, a simulation example and a practical electrical circuit model are conducted to verify the theoretical results. [ABSTRACT FROM AUTHOR]

This research aims to elucidate the intricate electrical and thermal characteristics of lithium-ion batteries under varying electrode types, encompassing Lithium Iron Phosphate (LFP), Lithium Nickel Manganese Cobalt Oxide (NMC), and Lithium Nickel Cobalt Aluminium Oxide (NCA). The experimental investigations were meticulously conducted employing two distinct methodologies: constant current discharge and pulse current discharge. Furthermore, a novel modeling technique was introduced, entailing the utilization of an electrical equivalent circuit model. The findings of this study reveal a complex, non-linear correlation between the quantity of charge and the open-circuit voltage (OCV) throughout the discharge progression. It was observed that the State of Charge (SOC), OCV, and terminal voltage (Vt) undergo alterations in a synchronous manner, albeit in a non-linear fashion. Particularly noteworthy is the observation that the LFP demonstrated a comparatively minimal fluctuation in voltage when juxtaposed with the NMC and NCA, all at changing of equivalent SOC levels. The generation of heat remained relatively uniform throughout the discharge process, exhibiting escalated rates when the SOC levels plummeted below 0.2 or escalated beyond 0.8. Regarding the electrodes, it is notable that the NMC variant showcased the highest rate of heat generation, with NCA and LFP in close succession. In the chapter concerning modeling, the suggested model demonstrated a noteworthy level of precision in predicting Vt values for SOC within the range of 1.0 to 0.2. The mean error margin was determined to be 0.004404 V, equivalent to 1.176% for NMC, -0.0256 V, corresponding to 1.126% for NCA, and -0.07 V, representing 2.601% for LFP. [ABSTRACT FROM AUTHOR]

Although scientific inquiry with simulations may enhance learning, learners often face challenges creating high demand for self-regulation due to an abundance of information in simulations and supplementary instructional texts. In this research, participants engaged in simulation-based inquiry about principles of electric circuits supplemented by domain-specific expository text provided on-demand. They received just-in-time inquiry prompts for inquiry behaviors, guidance to self-explain electrical principles, both, or neither. We examined how these interventions influenced participants' access of text information and achievement. Undergraduates (N = 80) were randomly assigned to one of four groups: (1) inquiry prompts and principle-based self-explanation (SE) guidance, (2) inquiry prompts without principle-based SE guidance, (3) principle-based SE guidance without inquiry prompts, or (4) control. Just-in-time inquiry prompts facilitated learning rules. However, there was no main effect of principlebased self-explanation guidance nor an interaction involving both interventions. Effects of just-in-time inquiry prompts were moderated by prior knowledge. Although principle-based self-explanation guidance promoted re-examination of text-based domain information, reading time did not affect posttest scores. These findings have important implications for instructional design of computerbased adaptive guidance in simulation-based inquiry learning. [ABSTRACT FROM AUTHOR]

Liquid manipulation using tubular actuators finds diverse applications ranging from microfluidics, printing, liquid transfer to micro‐reactors. Achieving flexible and simple regulation of manipulated liquid droplets during transport is crucial for the tubular liquid actuators to perform complex and multiple functions, yet it remains challenging. Here, a facile tubular actuator for directional transport of various liquid droplets under the control of an externally applied magnetic field is presented. The surfaces of the actuator can be engineered with submillimeter‐sized through‐hole pores, which enables the liquid droplet to be easily modulated in the transport process. Furthermore, the liquid actuator with featured through‐hole pores is expanded to function as a switch in an integrated external electric circuit by magnetically controlling the motion of a conductive liquid droplet. This work develops a strategy for regulating liquid droplets in the tubular actuation systems, which may inspire ideas for designing functional liquid actuators with potential applications in microfluidics, microchemical reaction, liquid switch, and liquid robotics. [ABSTRACT FROM AUTHOR]

Anderson localization and non-Hermitian skin effect are two paradigmatic wave localization phenomena, resulting from wave interference and the intrinsic non-Hermitian point gap, respectively. In this study, we unveil a novel localization phenomenon associated with long-range asymmetric coupling, termed scale-tailored localization, where the number of induced localized modes and their localization lengths scale exclusively with the coupling range. We show that the long-range coupling fundamentally reshapes the energy spectra and eigenstates by creating multiple connected paths on the lattice. Furthermore, we present experimental observations of scale-tailored localization in non-Hermitian electrical circuits utilizing adjustable voltage followers and switches. The circuit admittance spectra possess separate point-shaped and loop-shaped components in the complex energy plane, corresponding respectively to skin modes and scale-tailored localized states. Our findings not only expand and deepen the understanding of peculiar effects induced by non-Hermiticity but also offer a feasible experimental platform for exploring and controlling wave localizations. The authors use topoelectrical circuit to demonstrate "scale-tailored localization". Unlike Anderson localization, the number and length of localized modes is caused by long-range asymmetric coupling. This effect provides a powerful knob to control wave localization and a practical platform for exploring intriguing non-Hermitian effects. [ABSTRACT FROM AUTHOR]

In the present study, we establish the existence and uniqueness of solutions for nonlinear initial value problems and nonlocal boundary value problems associated with implicit fractional differential equations involving k,Ψ$$ \left(k,\Psi \right) $$‐Hilfer derivative operator. Furthermore, we explore the stability properties of these solutions in the sense of the Ulam–Hyers, Ulam–Hyers–Rassias, and their generalized stability concepts by proving and applying generalized Gronwall inequality. Lastly, we present the fractional RC$$ \mathcal{RC} $$ electric circuit model as an example to show the practical applicability of our main results. [ABSTRACT FROM AUTHOR]

Electrical arc fault detector development requires many tests to develop and validate detection algorithms. The use of artificial intelligence or mathematical transformation requires the use of consequential datasets of current signatures corresponding to as many different situations as possible. In addition, one of the main drawbacks is that these experiments take a great deal of time and are often laborious in the laboratory. To overcome these limitations, a virtual test bench based on the modeling of a modular 230 VAC electrical circuit has been developed. The simulated network is composed of different home appliances (resistor, vacuum cleaner, dimmer, etc.) and its configurations are those of single and combined loads. The fault modeled is an electric arc, modeled by active diode switching, which can be inserted at any point of the circuit. This arc model takes into account the random variations in the restrike and arc voltage. All the appliance models are validated by comparing the frequential (harmonic distortion) and temporal (agreement index) signatures of the measured currents in real situations to those obtained by modeling. The results obtained using the model and experiment network show that the current signatures are comparable in both cases. Further, two detection algorithms are tested on those current signatures obtained by the modeling and experimentation. The results are comparable and provide identical detection thresholds. [ABSTRACT FROM AUTHOR]

The October 2024 edition of the IETE Journal of Research features thirty articles covering various domains such as Communications, Computers and Computing, Control Engineering, Electromagnetics, Electronic Circuits, Devices and Components, and Power Electronics. The articles discuss topics ranging from privacy protection in Wireless Sensor Networks to innovative IoT threat detection and energy consumption analysis in dairy farms. The journal is edited by Shiban K Koul, Arun Kumar, and Ranjan K Mallik, who are esteemed professionals in their respective fields. [Extracted from the article]

Approximate computing enables high performance and efficiency of execution by using the overhead on compute units of a processor to give high speed. The speed and system delay are inversely proportional, necessitating massive parallel processes with massive hardware and power dissipation. Energy and area-efficient systems can be realized by reducing system accuracy and dependability. Approximate computing techniques can be used to reduce the number of computing resources needed for a given task and improve the performance of a system. This can be accomplished by lowering a computational model's accuracy and decreasing complexity, reducing power consumption, latency, and area requirements. This study examines an electrical circuit that performs multiplication of two equal integers and it proposes the use of a carry-in adder with two approximation compressors to reduce the size, latency, and power consumption while maintaining the same level of accuracy as current designs. The suggested algorithms were implemented in Xilinx Vivado and their effectiveness was evaluated using numerical performance metrics, including error rate, power consumption, delay, and power delay product in output result. The compressors suggested are used to implement 8 × 8 and 16 × 16 Dadda multipliers that perform comparably to state-of-the-art approximation multipliers. [ABSTRACT FROM AUTHOR]

Electric signal accelerates full‐thickness wound healing in the clinic, which is usually generated by a large power generation system and requires delicate control by authorized personnel. Here, a self‐powered flexible and biocompatible thermoelectric device with exceptionally high power generation efficiency is developed. It generates 10 mV voltage at a temperature gradient of 10 K, outperforming all reported flexible thermoelectric devices. Accordingly, it can directly and efficiently convert the omnipresent heat in the skin to electricity at the microvolt level. The output electricity activates and upregulates the expression of Piezo1‐mediated pathways that are associated with tissue regeneration, accelerating the cell migration and proliferation in vitro and healing the wound 4 days faster in vivo. Importantly, the thermoelectric device fast‐heals the wound without involving any additional electric circuit such as an amplifier. These advantages will revolutionize the designing of self‐powered wearable bioelectronics for diagnosing, monitoring, and treating various pathological conditions employing the skin heat. [ABSTRACT FROM AUTHOR]

Electric fences used to create protected areas (PAs) are prone to faults that affect their operation. The conventional method of measuring the voltage of the fence periodically to detect faults and walking along the fence to locate the faults is inefficient and time consuming. This paper presents a low‐cost Raspberry Pi time domain reflectometer (TDR) for fault detection and localisation in electric fences. The system is designed using cheap off‐the‐shelf components. It uses time domain reflectometry to detect hard (open and short circuit) faults in electric fences. Time domain reflectometry is a method of detecting and locating faults in electrical cables. The Raspberry Pi TDR is evaluated and it has successfully detected and located open circuit and short circuit faults in electric fences with a mean absolute error of 1.52 m. The Raspberry Pi TDR offers the potential to remotely monitor electric fences autonomously, hence improving their effectiveness. [ABSTRACT FROM AUTHOR]

Broadband vibration attenuation is a challenging task in engineering since it is difficult to achieve low-frequency and broadband vibration control simultaneously. To solve this problem, this paper designs a piezoelectric meta-beam with unidirectional electric circuits, exhibiting promising broadband attenuation capabilities. An analytical model in a closed form for achieving the solution of unidirectional vibration transmission of the designed meta-beam is developed based on the state-space transfer function method. The method can analyze the forward and backward vibration transmission of the piezoelectric meta-beam in a unified manner, providing reliable dynamics solutions of the beam. The analytical results indicate that the meta-beam effectively reduces the unidirectional vibration across a broad low-frequency range, which is also verified by the solutions obtained from finite element analyses. The designed meta-beam and the proposed analytical method facilitate a comprehensive investigation into the distinctive unidirectional transmission behavior and superb broadband vibration attenuation performance. [ABSTRACT FROM AUTHOR]

We apply a well known technique of theoretical physics, known as geometric algebra or Clifford algebra, to linear electrical circuits with nonsinusoidal voltages and currents. We rederive from the first principles the geometric algebra approach to the apparent power decomposition. The important new point consists of endowing the space of Fourier harmonics with a structure of a geometric algebra (it is enough to define the Clifford product of two periodic functions). We construct a set of commuting invariant imaginary units which are used to define impedance and admittance for any frequency. [ABSTRACT FROM AUTHOR]

Recently, an increasing number of people have employed do-it-yourself (DIY) and do-it-with-others (DIWO) techniques and processes to develop unique technology products. This trend is commonly called the maker movement and fosters the creation of own electronic and mechanical devices and tools. Oscilloscopes are really useful tools to diagnose problems and analyze electronic devices and electrical circuits, and thus they should not stay outside this trend. To contribute to this field, an architecture to make low-cost portable digital oscilloscopes is proposed. The proposal is mainly based on general-purpose microcontrollers and operational amplifiers. Following this approach, a portable oscilloscope with two input channels, a graphic display, a synchronism detector, internal and external triggers, and a digital signal analyzer function is designed. Furthermore, different options for the implementation are proposed and discussed. [ABSTRACT FROM AUTHOR]

This article evaluates energy quality in individual circuits within an industrial electrical system and its impact on common connection point parameters. The research is crucial due to rising challenges in power quality arising from increased nonlinear electrical loads in industrial processes. The study involves sequential steps, covering the industrial electrical system's description, power quality parameters analysis, and issue identification. A comprehensive assessment was conducted on a 3,000 kVA, 13.8 kV/460 V point of common coupling (PCC) transformer, and 10 transformers (10 to 250 kVA) supplying individual circuits. Findings indicated load factors below 70% in all transformers and a power factor below 0.9 in eight. Issues like voltage variation, current imbalance, and harmonic distortion were identified in nine transformers supplying individual circuits, while the PCC exhibited no power quality problems. The research emphasizes the importance of including individual circuits in power quality assessments, as compliance with regulatory limits at the PCC may not guarantee the absence of power quality issues in individual circuits, affecting equipment lifespan and increasing energy losses. [ABSTRACT FROM AUTHOR]

Secondary school students encounter a wide range of electronic devices in their everyday lives that are not usually covered in physics classes. Examples include mobile phone power adapters that convert high-voltage alternating current to low-voltage direct current. However, such examples are often not used sufficiently in the classroom to provide students with insights into (a) the specific applications of the electronic components used and (b) the underlying electronic design process. To fill this gap, we have designed a new context-based, easy-to-implement teaching-learning sequence that guides students to how to use the electronic design and simulation program KiCad which is being widely used by professionals in the field, (2) build their own analog experimental setup of a mobile phone power supply, and thus (3) understand how a mobile phone power supply works. The presented part of the teaching-learning sequence focuses on the use of KiCad and is designed to allow students to work individually and in groups to learn according to the think-pair-share principle based on a set of tasks we created. This paper examines the pedagogical potential of KiCad and provides a detailed description of the teaching-learning sequence and reports on initial classroom experiences: A total of N = 28 students aged 16 to 17 years participated in the unit as part of an extracurricular course and completed a questionnaire based on the Technology Acceptance Model to investigate the perceived ease of use and usability of the KiCad software. We found that despite the fact that the students had not used KiCad before, they were quite positive about the educational material as a whole and the KiCad software in particular. [ABSTRACT FROM AUTHOR]

A graph with directed edges is referred to be directed graph. It is possible to study and resolve problems with social connections, shortest paths, electrical circuits, etc. using directed graphs. D. Molodtsov proposed soft set theory as a mathematical framework for handling uncertain data. Nowadays, a lot of people employ soft set theory to solve decision-making problems. We present soft directed graphs by extending the notion of soft set to directed graphs. A parameterized perspective for directed graphs is provided by soft directed graphs. In this study, we look at various characteristics of soft directed graphs' homomorphic product and restricted homomorphic product. [ABSTRACT FROM AUTHOR]

We present a method for simulating any non-interacting and time-periodic tight-binding Hamiltonian in Fourier space using electric circuits made of inductors and capacitors. We first map the time-periodic Hamiltonian to a Floquet Hamiltonian, which converts the time dimension into a Floquet dimension. In electric circuits, this Floquet dimension is simulated as an extraspatial dimension without any time dependency in the electrical elements. The number of replicas needed in the Floquet Hamiltonian depends on the frequency and strength of the drive. We also demonstrate that we can detect the topological edge states (including the anomalous edge states in the dynamical gap) in an electric circuit by measuring the two-point impedance between the nodes. Our method paves a simple and promising way to explore and control Floquet topological phases in electric circuits. [ABSTRACT FROM AUTHOR]

Drawing inspiration from modern integrated circuit systems composed of various electronic components built on a single silicon platform, the emerging integrated photonics can also follow a similar trend in the pursuit of expanded optical functionalities in constructing compact optoelectronic systems. Herein, vertically integrated a micro‐scale light‐emitting diode (micro‐LED) array with a photodetector (PD) side‐by‐side through a transparent sapphire substrate is proposed. The downward emitted photons from the micro‐LEDs can easily transmit through the transparent sapphire and then be captured by the PD fabricated on the backside of the sapphire. Additionally, by integrating a feedback electrical circuit, a self‐stabilized light output power is demonstrated from the micro‐LED array in such vertically integrated LED/PD architecture, which cannot only monitor the fluctuation of light intensity from the micro‐LED array over time but also provide a constant output feedback to ensure a stable light output power. Such a compact and stable DUV light source composed of micro‐LED array is then employed for constructing a DUV maskless photolithography system. To best of our knowledge, this is the first demonstration of maskless photolithography based on DUV micro‐LED active matrix. The proposed vertically‐stacked optical device architecture by leveraging the transparent substrate offers a new path toward the realization of future integrated photonic systems. [ABSTRACT FROM AUTHOR]

Fe-based materials exhibiting high dielectric constants have been attracting great attention due to their potential for application in electronic devices. In this work, iron niobate (FeNbO 4) fibres were produced by the Laser Floating Zone technique, applying three different growth speeds: 5, 10 and 25 mm/h. The XRD patterns showed the presence of two phases, being the FeNbO 4 the major one in all the samples. The effect of the growth speed is well perceptible in the morphology of the fibres. The dielectric measurements revealed that all samples have at least one dielectric relaxation phenomenon that is thermally activated, with the activation energy, estimated through the Arrhenius law, presenting values between 0.057 and 0.072 eV. The Nyquist plots showed the presence of a single semicircle for each temperature, that could be modelled by an equivalent electrical circuit consisting of an offset resistance in series with a parallel combination of a grain resistance and a grain constant phase element. The grain resistance increased with the increasing growth speed, from 574 to 64497 Ω, with the constant phase element showing the opposite trend, decreasing from 0.40 to 0.17 nF. [Display omitted] [ABSTRACT FROM AUTHOR]

Over 60% of reported failures for reactive power compensation systems are given for damage to electrical circuit breaker contacts. This paper presents a study on the development of microwave technology for sintering of W–Cu–Cr alloys at 1012 °C for 65 min using 623.38 W microwave power, as well as microwave joining at 231 °C of the W–Cu–Cr composite material on body contact using 475 W microwave power for 55 s. The joined components were subjected to mechanical and electrical tests in accordance with ICE standards to validate the applied technology. Tests of connection–disconnection of the electrical contacts were carried out in accordance with the maximum number of disconnections allowed by the manufacturer (2 cycles/min): 25 s rest time and 5 s operating time under load. The components of the electrical contact after 111237 switches were analyzed under a microscope revealing a reduction of the damaged area by 27% compared with the original contact. [ABSTRACT FROM AUTHOR]

In this investigation, the analytical behavior of two prominent nonlinear wave equations, namely the doubly dispersive equation (DDE) and the Ablowitz-Kaup-Newell-Segur equation (AKNSE), have been scrutinized. Bifurcation analysis, sensitivity as well as chaotic phenomena are also performed for the earlier-mentioned dynamical systems. These analyzes have profuse applications in the field of electrical circuits and control systems, phase transitions in materials, climate patterns, chemical reaction networks, forecasting market trends, signal processing, and quantum mechanics. Using an advanced mathematical technique, the exact solutions of the mentioned two-wave equations with singular bell-shaped soliton, bell-shaped soliton, anti-bell-shaped soliton, singular soliton, and singular periodic soliton have been studied. The technique utilized in the study is dependable for solving complex nonlinear problems in various natural science and engineering disciplines employed by many researchers. This study identified ten general solutions and ten particular solutions for the two mentioned equations that are novel and precise wave solutions. The solutions obtained in our study are significant not only for understanding the mentioned field but also may be used in revealing other interesting phenomena, such as the analysis of seismology, the study of compulsive collapse, and the study of the material effects and inner construction of solids. [ABSTRACT FROM AUTHOR]

This paper presents interactive liquid crystal fiber arrays that can actuate in a way perceptible by human touch. The fibers are actuated via a computer interface, enabling precise control over actuation direction, magnitude, and frequency. Unlike conventional methods, our technique initiates the actuation at the base of the fibers, which is enabled by fabricating the fibers directly onto an electrical circuit. Fiber actuation is achieved by localized addressing of an in situ formed radially aligned segment. This induces reduction in the scalar order parameter and leads to deformation of the fiber base, causing bending toward the activated region. Extensive modeling validates this actuation mechanism and identifies optimal conditions and actuation strategies for achieving the desired responses. The actuation process is rapid, is highly reversible, and maintains excellent performance over repeated (>200) cycles. These liquid crystal fiber arrays provide a safe contact with humans or other objects, making them highly suitable for applications in smart wearable devices and immersive interfaces. [ABSTRACT FROM AUTHOR]

Silicon steel sheets (SSSs), serving as the principal constituent of the magnetic circuit in electric machines, necessitates precise modelling and accurate computation using magnetic circuit theory as a prerequisite for analysing the characteristics of electric machines. Nevertheless, the conventional magnetic circuit theory, limited to a single reluctance component, fails to address the phase relationship between magnetomotive force and magnetic flux, and inadequately represents the magnetic flux distribution observed under high‐frequency conditions. Consequently, the existing magnetic circuit model for SSSs remains imperfect in its current state. Fortuitously, the advent of magductance has effectively addressed these challenges. Building upon magductance, this study deduces the fundamental laws and theorem within the vector magnetic circuit theory. Subsequently, a distributed parameter vector magnetic circuit model for the SSSs is constructed, accompanied by the derivation of expressions pertaining to its reluctance and magductance. The authors propose the transfer function composed of reluctance and magductance parameters, successfully resolving the phase between the magnetic circuit vectors, the magnetic flux distribution, and the magnetic circuit loss under different frequencies for SSSs. Finally, experimental findings affirm the efficacy and validity of the distributed parameter vector magnetic circuit model for SSSs. The proposal of vector magnetic circuit theory opens a whole new door for the analysis, computation, and optimisation of electric machines. [ABSTRACT FROM AUTHOR]

This paper presents four new sinusoidal oscillators using a commercially available integrated circuit (IC). The proposed circuits are simple topologies that employ a single commercial IC, LT1228. It is connected to passive element, consisting of four resistors and two capacitors. All derived oscillator circuits have low output impedance, allowing them to connect to other circuits without requiring an additional buffer. Using an active LT1228 device enables electronic adjustment of parameters in the proposed circuits. A feedback resistor can be used to change the output signal's amplitude without affecting the oscillation's frequency or condition. We performed both simulations using the PSPICE program and experiments to confirm the accuracy of all proposed oscillator circuits. The best total harmonic distortion was 0.13% for the proposed oscillator circuit 3. Adjusting the maximum amplitude using a resistor provides a gain of roughly 1.5-16.5 dB for the proposed oscillator circuit no. 1. [ABSTRACT FROM AUTHOR]

This article discusses an identification and modeling approach of a reluctance synchronous motor (RSM) based on the running rotor technique. The applied flux linkage approximation functions reflect the self-saturation and cross-saturation effects, and the applied mathematical model is continuous and differentiable. The proper design of the experiment is discussed, and relevant recommendations are made to ensure the mitigation of procedural mistakes in the experiments. A detailed analysis of the impact of configuration faults on the obtained experimental data is provided, considering distortions in the obtained flux linkage and inductance surfaces. Considering the achieved model accuracy, a novel model evaluation considering the achieved model accuracy technique based on transient current response is proposed. [ABSTRACT FROM AUTHOR]

Battery modeling and state of charge (SoC) estimation are critical functions in the effective battery management system (BMS) operation. Temperature directly affects the performance and changes the model accuracy of a battery. Most studies have focused on estimating the internal temperature of the battery from the surface temperature of the battery with the help of sensors. However, due to the high number of cells in battery packs, the increase in sensor costs and the number of parameters have been ignored. Therefore, this article presents a new framework for the temperature effect using the electrical circuit model. The terminal voltage of the battery includes the effect under different operating conditions. This effect was associated with internal resistance in the battery model. The developed temperature-effective battery model was tested at different temperatures and operating currents. The model was validated with a maximum average root mean square error of 0.05% from the test results. The SoC of the LTO battery was estimated with the sigma-point Kalman (SPK) filter incorporating the developed model. The maximum average root mean square error in the estimation results is 0.11%. It is suitable for practical applications due to its low cost, simplicity, and reliability. [ABSTRACT FROM AUTHOR]

The swing torque and rotational torque after the spherical bearing is installed directly affect the performance of the spherical bearing. At this stage, the friction torque detection equipment of the spherical bearing is mainly used to detect uninstalled bearings. A set of rotation and swing after the bearing is installed is designed. Torque detection system. The detection principles of rotational torque and swing torque required for flexibility detection were analyzed, the functional design requirements and main technical indicators of the detection system were clarified, and the overall design plan of the detection system was established; the host structure of the detection system was designed, including rotational torque detection system, swing torque detection system, clamping system and calibration system; completed the scheme design of the detection control system, selected the torque sensor and servo motor, designed the main electrical control circuit of the detector; conducted error analysis of the detector. [ABSTRACT FROM AUTHOR]