Induction Of Behavior Research Articles

High-Frequency Negative Capacitance in Graphene Quantum Dots/Lanthanum(III) Hydroxide-based MIS Heterostructure

Lanthanides have significant potential for electronic technologies based on graphene quantum dots (GQDs), as they have unique electronic configurations characterized by 4f electrons. In this context, lanthanum(III) hydroxide nanoparticles (La(OH)3NPs) are used as dopants for polyethyleneimine (PEI)-doped nitrogen (N)-doped graphene quantum dots(PEIGQDsN) in this study. Using a novel green method, the La(OH)3NPs-doped PEIGQDsN nanocomposites are prepared from La(NO)3 in a single step and exploited as an interlayer in a metal/interlayer/semiconductor (MIS) heterojunction with Au and n-Si. Capacitance & conductance-voltage (C-V & G/ω-V) characteristics of the Au/La(OH)3NPs doped PEIGQDsN/n-Si MIS heterojunction have been investigated as a function of frequency in the wide 500 Hz to 3 MHz range from −3 V to 5 V, at 300 K. It has been observed that the structure is highly sensitive to the frequency. In particular, at high frequencies, above 1.5 MHz, the positive capacitance (PC) transforms into a negative capacitance (NC) in forward bias. In addition, impedance measurements at high frequencies were carried out after the measurements in the dark, while the surface of the structure was illuminated at 100 mW/cm2. At the frequencies of 2 MHz and 3 MHz, where inductive behavior was observed, the light refilled the depleted trap levels, catalyzing the transition from NC to PC in forward bias. These findings suggest that the capacitance and conductance of the heterojunction have a remarkable frequency sensitivity, particularly evident at higher frequencies. The outcomes of this study are poised to significantly influence the comprehension of carbon-lanthanides-based electronic technology, and enable the creation of new hybrid functional materials for use in electronic or optoelectronic applications.

Design and Performance Analysis of A Linear Switched Reluctance Motor Considering End Effects

Introduction: In recent years, linear actuators have gained significant attention due to their ability to provide direct linear movement without the need for motion transformation devices. One significant challenge in the design and modeling of linear actuators is the occurrence of longitudinal end-effects. The finite length of the translator stack in linear actuators causes an unbalanced phase force, leading to discrepancies between the phases at the end and center of the actuator. Neglecting these end-effects can lead to inaccuracies in the actuator's performance and control. Methods: The objective of this study is to develop a comprehensive approach for the design, sizing, and modeling of the actuator to ensure optimal performance. An energy conversion procedure calculates the thrust force and determines the actuator's geometrical parameters. A numerical model based on the finite element method is developed to analyze the actuator's magnetic behavior and establish its characteristics. Furthermore, a thorough analysis of the end effect is conducted using two-dimensional finite element analysis. Results: To accurately capture the actuator's dynamic response and enable precise control, a mathematical model is formulated, incorporating the nonlinear behavior of inductance and incorporating the end effect factor. The proposed model demonstrates high accuracy and provides a solid foundation for the control of the linear switched reluctance actuator. Conclusion: Overall, this study contributes to the advancement of direct drive systems for industrial applications by providing a detailed design procedure and an accurate modeling approach for the linear actuator, enabling more efficient and precise control strategies.

Effect of Tensile Loading on the Residual Stress Relaxation Behavior of Induction Hardened SCM440 Steel with a Shallow Hardened Layer

Effect of Tensile Loading on the Residual Stress Relaxation Behavior of Induction Hardened SCM440 Steel with a Shallow Hardened Layer

Active power compensation circuit for resonance mitigation and harmonic reduction in microgrid system

The nature and behavior of capacitors, transformers, inductors, active compensators, and non-linear loads can produce power resonance. Unfortunately, the presence of a resonance phenomenon can have a negative impact on system stability and lead to catastrophic power system failures. Therefore, even when using modern or conventional techniques to enhance total harmonic distortion (THD) or improve input power factor (IPF), it is necessary to avoid resonance. An active power compensation circuit (APCC) is proposed and designed to function with two categories of linear/non-linear loads. The APCC has been implemented and regulated using an adjusted pulse width modulation technique. The aim of the suggested APCC is to minimize AC side distortions, improve the IPF, and mitigate harmonics resonance at the same time. The simulation results demonstrate that the proposed APCC investigates the aim function of this study by absorbing harmonics, correcting IPF, and eliminating resonance problems under both transient and steady-state operating conditions. The supply voltage and current THD values for the first power circuit type are reduced by 96.7 % and 96.3 %, respectively, at α=30°. Meanwhile, for the second power circuit, the THD is reduced by 91.92 % and 90.4 %. Also, the IPF changed for the first and second power circuits from 0.72 and 0.86 to almost unity. These results demonstrated the effective performance of the APCC circuit and controller in reducing power harmonics, eliminating power resonance, and modifying power factors.

Neural modeling of power nonlinear inductors by the E-α\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha $$\\end{document}Net network

In this paper, a model for nonlinear ferrite power inductors based on the α\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha $$\\end{document}Net neural network is proposed. The model is able to reproduce the ferrite power inductors inductor behavior up to saturation, considering the core temperature. The α\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha $$\\end{document}Net neural network was used for its generalization capability considering a hybrid approach encompassing a classical weighted interpolation. The model’s effectiveness was experimentally verified by calculating the current flowing through two inductors in an electric circuit in different operating conditions, and has been compared with the two main models found in literature to show the improvement both in terms of the maximum value of the estimated current and the root mean square error. The modeling procedure can be easily extended to inductors with different sizes and core materials due to the features of the α\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha $$\\end{document}Net network and the hybrid approach to retrieve data.

Frequency-Dependent Grounding Impedance of a Pair of Hemispherical Electrodes: Inductive or Capacitive Behavior?

This article is the authors’ last contribution to a trilogy of research papers submitted to Energies’ Special Issue on Electromagnetic Field Computation, aimed at the theoretical analysis and numerical computation of the frequency-dependent complex impedance of hemispherical electrodes. In this work, we consider a pair of distant identical hemispherical electrodes buried in the ground, whose constitutive parameters (conductivity and permittivity) are assigned diverse values. Simulation experiments carried out using a full-wave finite element method, considering different combinations of the earth’s constitutive parameters, reveal that the grounding impedance of the electrode system can exhibit surprisingly varied frequency behavior. For frequencies close to zero, the impedance can start out inductive or capacitive, then go through a number of resonant transitions between inductive and capacitive states, finally tending towards purely resistive behavior. The results are interpreted using theoretical approximations valid for low- and high-frequency regimes.

Application of operando ORP-EIS for the in-situ monitoring of acid anion incorporation during anodizing

Operando odd random phase electrochemical impedance spectroscopy (ORP-EIS) is applied to monitor the anodizing process of AA2024 in acidic media. The impedance data reveals the presence of inductive behavior during the process. We correlate this inductive behavior to the acid anion incorporation during anodizing using the surface charge approach. Moreover, the impact of anodizing parameters – including anodizing DC potential, electrolyte type and concentration – is studied on the inductive behavior, and consequently on the acid anion adsorption and incorporation. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is employed to support the operando ORP-EIS results. We conclude that operando ORP-EIS during anodizing can predict acid anion incorporation into the oxide layer.

Atomistic-scale insights into hydrogen diffusion barrier in nickel hydride: Complex interplay between short- and long-range hydrogen arrangement and hydrogen concentration

Metal hydrides, such as those containing Pd, Ni and Mg, are being considered as potential candidates for hydrogen storage applications. The sluggish hydrogen uptake/release in such materials at ambient conditions presents a major issue. The timescales are dictated mainly by diffusion, as it is usually the rate-controlling step. In order to identify practical strategies for improving the kinetics, one must therefore gain an atomistic-scale understanding of the hydrogen diffusion, which is generally lacking from experiments. We address this gap by analyzing the hydrogen hopping mechanism and the associated barriers in two million different hydrogen configurations in NiHx (x = 0–1) using computational techniques. A distribution of hopping barriers is observed. The barriers lie between 0.3–0.7 eV. Three factors, namely, the short- and long-range hydrogen arrangement and the hydrogen concentration influence the barrier. We also show that depending on these factors, two different H hopping mechanisms may prevail. At higher H concentration, the lattice expands by as much as 19 % by volume, making it easier for the hydrogen atom to hop. Therefore, hydrogen diffusion is sluggish in the initial α phase, which may explain the experimentally-observed induction behavior. This study highlights the complexity associated with the metal hydride systems and provides the basis for further molecular scale kinetic studies of metal hydride systems.

Characterization of Non-linear Inductors Including Thermal Effects for Power Applications

This paper focuses on the behavior of non-linear inductors employed in DC/DC switching converters considering the effects due to variations of both current and temperature. The characterization of the inductors is performed by a buck converter operated to stimulate the inductor under test by a constant current with superimposed a large signal. The measurements are carried out for several temperature values of the inductor. Data are automatically collected by a novel virtual instrument developed by the authors in LabVIEW® environment, aiming to obtain a polynomial based analytical model. The deep knowledge of the inductor model allows its design to be optimized improving the power density of the converter.

Effects of the Mutual inductances on the Switched Reluctance Machines

There are many studies which discuss the mutual inductances in the Switched Reluctance Machine – SRM. Most of these studies said that the influence of inductance is negligible. In this paper the influences of those inductances are analyzed. This work presents experimental measures and analysis of these quantities on prototypes of SRM with various settings aiming to contribute to the knowledge of the subject. The variations of the inductance profile due to the current in the active phase, the angular position of the rotor and saturation are taken into account. Surfaces are presented to summarize the behavior of the self inductance and of the mutual inductances gotten from different machines. It is presented the simulation of the SRM in generator mode taking into account the mutual inductances. The results are presented and discussed conclusively, and then some propositions are made. The results presented here reveal the relative dimension and the influence of the mutual inductances and show that they have the potential to indicate the position of the rotor of the machine, thus avoiding the use of electronic sensors allowing sensorless techniques. Furthermore, this article highlights the importance of considering the mutual inductances in the design, mathematical modeling and simulation of SRM in order to improve de machine performance.

Li-ion cell impedance identification in the time domain as an alternative to identification in the frequency domain

Electrochemical Impedance Spectroscopy (EIS) is a widely used tool for selecting a pertinent Equivalent Circuit Model (ECM) of Li-ion cells which is characterized by non integer order operators. The main drawback of EIS is the long time required to scan a whole spectrum down to low frequencies. Thus, chronopotentiometry (CP) is an alternative method which consists in identifying impedance parameters using an excitation current sequence lasting a few seconds and the corresponding induced voltage variations. An impedance fractional model needs to be synthesized in order to allow simulation also in the time domain. The pertinence of CP is demonstrated using experimental results obtained with a Samsung 3.4 Ah Li-ion cell. Due to its inability to take into account the inductive behavior, fractional model used in the time domain exhibit limitations. Nevertherless, parameters identified in the time domain present similar results to the ones identified in the frequency domain under the condition of a restricted frequency range.

An Informetric View to the Negative Capacitance Phenomenon at Interlayered Metal-Semiconductor Structures and Distinct Electronic Devices

Negative Capacitance (NC) phenomenon, which can be explained as the material exhibiting an inductive behavior, is often referred to as "anomalous" or "abnormal" in the literature. Especially in the forward bias/deposition region, the presence of surface states (Nss) and their relaxation times (τ), series resistance (Rs), minority carrier injection, interface charge loss in occupied states under the Fermi energy level, parasitic inductance, or poor measuring equipment calibration problems can be counted among the causes of this phenomenon. Studies on NC behavior have shown that this behavior can be observed for different frequencies, temperatures, and related parameters at forward biases. However, the NC behavior, which appears as an unidentified peak in admittance spectroscopy data, is not yet fully understood. Ultimately, this study aims to compile and analyze the NC reported in selected scientific studies, investigate the source of this phenomenon, and observe statistics in a general view.

“Electrochemical reduction of HMF to synthesize added value compounds using CuAg electrodes”

In biorefining, Green electrochemistry offers an intelligent approach to produce valuable chemicals that are not derived from fossil fuels. In this study, we demonstrate the electrochemical reduction of 5-hydroxymethylfurfural (HMF), a biomass-derived compound, into 2,5-bis-hydroxymethylfuran (BHMF), which serves as a fundamental component in the polymer industry. This reaction was performed using Cu and Ag electrodes, but a better performance was obtained by combining the properties of the two metals in Ag decorated Cu foils. Additionally, by means of Impedance Spectroscopy IS we could uncover that the incorporation of Ag onto Cu electrodes not only increases the active area of the electrodes but also improves both the HMF adsorption on Cu and the catalytic properties of Ag. This synergistic effect leads to a more efficient reduction of HMF. Nonetheless, the diffusion of reactive species imposes a constraint on the increase in current. Finally, the observed inverted hysteresis in the cyclic voltammetry is attributed to variations in the amount of HMF adsorbed on the electrode surface during the forward and reverse directions of the cyclic voltammetry. Unlike other systems such as solar cells, where this effect is linked to the presence of a low frequency inductive behavior which, in this case, plays a negligible role.

Evaluation of eggshell lime as green accelerator on palm oil fuel ash concrete production: Effect of thermal treatment

This paper presents the potential use of eggshell powder (ESP) as green accelerator in ground palm oil fuel ash (GPOFA) concrete. Three categories of ESPs namely uncarbonised ESP (UC-ESP), carbonised ESP (C-ESP) and decarbonised ESP (DC-ESP) corresponding to no calcination and calcination at temperatures of 750 and 1000 °C, respectively, were prepared and studied. In addition, ESPs was used as cement replacement (0, 5, 10, 15, and 20 wt%) in GPOFA concrete and their performance were examined in term of reactivity, workability, heat hydration, compressive strength and microstructure performance. It was found that the presence of UC-ESP, C-ESP and DC-ESP can provide a low, medium and superior accelerator behaviour in the early age of GPOFA concrete. Overall, the GPOFA concrete combined with DC-ESP revealed an excellence SiO2-CaO reactivity, giving a twice compressive strength at early age and provides inductive hydration behaviour with low hydration temperature and significant improvement in dense gels formulation. Hence, this study provides a positive impact for rapid construction technology. As a conclusion, modified ESP is a highly potential as partial cement replacement and accelerator for concrete.

Energetic perspective on emergent inductance exhibited by magnetic textures in the pinned regime

Spatially varying magnetic textures can exhibit electric-current-induced dynamics as a result of the spin-transfer torque effect. When such a magnetic system is electrically driven, an electric field is generated, which is called the emergent electric field. In particular, when magnetic-texture dynamics are induced under the application of an AC electric current, the emergent electric field also appears in an AC manner, notably, with an out-of-phase time profile, thus exhibiting inductor behavior, often called an emergent inductor. Here we show that the emergent inductance exhibited by magnetic textures in the pinned regime can be explained in terms of the current-induced energy stored in the magnetic system. We numerically find that the inductance values defined from the emergent electric field and the current-induced magnetization-distortion energy, respectively, are in quantitative agreement in the so-called adiabatic limit. Our findings indicate that emergent inductors retain the basic concept of conventional inductors; that is, the energy is stored under the application of electric current.

Investigation of charge-carriers dynamics and sub/super-linear response for La0.8Na0.2-x□xMnO3 (x = 0 and 0.1) perovskite ceramics

La0.8Na0.2-x□xMnO3 (x = 0 and 0.1) compounds were prepared by solid-state reaction. XRD patterns were used to check the structural properties. Experimental results were discussed in terms of different theoretical approaches. The temperature dependence of DC-conductivity displays the presence of a metal-semiconductor transition for x = 0 and 0.1. The introduction of 10%-vacancy provokes a significant increase in the conductivity. The electrical conductivity is explained by many kinds of hopping each one is pronounced in a different temperature region. Two deviation temperatures are observed. These temperatures coincide with the ANC temperatures and the change in the conduction process. For x = 0.1, the Nyquist diagrams shows the presence of a high frequency inductive behavior. AC-conductivity spectra obey to the JPL and DJP. Then, SPL and NCL behaviors appear at high frequency range. The power "s" presents the contribution of numerous conduction models. The scaling behavior reveals that the conductivity spectra obey to the TTS principle.

The evolution of coil-less inductive behaviour in La-doped Sr2MnO4

The evolution of coil-less inductive behaviour in La-doped Sr2MnO4

Measurement and Calculation Techniques of Complex Permeability Applied to Mn-Zn Ferrites Based on Iterative Approximation Curve Fitting and Modified Equivalent Inductor Model

In many cases, power inductors are responsible for most of the power loss, volume, and cost if applied to high-frequency power electronics applications. It is desirable to optimize their design by the proper calculation of winding and core loss. It allows faster and cheaper commercial product release, which is the key to being successful in a highly competitive market. This is only possible if existing calculation techniques and technical data given by, e.g., core manufacturers, are verified and correct; otherwise, the inductor optimization process is less precise and requires several iterations to achieve good convergence. This paper addresses existing and proposes improved measurement and calculation techniques with regard to complex permeability, one of the key quantities that define inductor behavior in the frequency domain. This is done through impedance measurement and improved definition of the equivalent inductor model. Moreover, the proposed calculation techniques fulfill the need for the simple, accurate analytical methods required in commercial designs.

A novel heuristic algorithm for solving engineering optimization and real-world problems: People identity attributes-based information-learning search optimization

With the scale and dimension of engineering optimization and real-world problems increasing, it will be difficult to find the optimum solutions. This paper proposes a novel people identity attributes-based heuristic technology, named the People Identity Attributes-based Information-learning Search Optimization (ISO), inspired by people’s psychological assessment and learning behaviors for information resources based on the social status-based identity attribute and the self-survival demands-based identity attribute. For the former, a four-level information delivery mechanism is constructed through leader, manager, executor, and freelancer, emphasizing global optimization. For the latter, the staged transforming model based on random accumulation and directed induction behaviors are constructed according to self-survival demands, emphasizing global optimization and exploration. The dual identity attributes-based search strategy emphasizes psychological assessment and selection for the information loss, including the learning behavior for two kinds of information resources with different identity attributes, and the recovering behavior for the information loss by constructing the information resilience equation, which emphasizes local optimization and exploitation. This paper qualitatively analyzes the swarm behavior, search history, and the exploration and exploitation capabilities of ISO. The optimization performances are quantitatively analyzed for ISO and 9 competitive algorithms on 39 benchmark tests, including the convergence, solution accuracy, robustness, sensitivity, significance, statistical investigation-based Wilcoxon test and Friedman test. The scalability of ISO is investigated on CEC2017 (30Dim, 50Dim, 100Dim) and the latest CEC2022 (10Dim, 20Dim) suites. The results reveal that compared to other competitive algorithms, ISO possesses best computing performance with ranking the first in all competitors. In addition, the proposed ISO and 12 competitors consider 10 constraint engineering optimization problems and the real application of path planning with multiple obstacles, suggesting that ISO possesses significant optimization performance.

Non-stationarity in electrochemical impedance measurement of Mg-based materials in aqueous media

For most bare Mg-based materials in aqueous media, an inductive behavior can be detected at the low frequencies electrochemical impedance spectroscopy (LF-EIS) measurement, which potentially can be associated with the non-stationarity of the system. The non-stationarity in EIS measurement leads to inaccurate acquisition of experimental data and, thus, misunderstanding of the electrochemical behavior of tested samples. To investigate the non-stationarity of EIS measurements on Mg-based materials in aqueous media, conventional EIS measurements are performed on pure Mg and several representative Mg alloys (AZ31, AZ91, AM50) in NaCl and Na2SO4 solutions. The results indicate that the impedance spectra of Mg-based materials in aqueous media is influenced by the internal non-stationarity of the Mg-electrolyte system and the external non-stationarity induced by EIS measurement. Multisine odd random phase EIS (ORP-EIS) measurements were performed to visualize the non-stationarity and non-linearity of the system. Moreover, the comparison of conventional and ORP-EIS results exhibits the difference between pseudo and real inductive behavior for the AZ31-NaCl system. Accordingly, the origin of the inductive behavior of Mg-based materials is discussed.