1,720,999 research outputs found
An empirical dynamic model of Hall-effect sensors
Full text linkWe present an empirical, equivalent, dynamic model of Hall-effect sensors that is based on a parallel circuit composed of a controlled current generator, a resistor, and a capacitor. This solution provides optimal description of the dynamic response of the probe and easily takes into account the loading and parasitic capacitive effects. The proposed model is verified against empirical AC measurements to demonstrate the quality of the model in dynamic conditions
Sensors for next-generation smart batteries in automotive: A review
No full textInnovation of the battery technology is of paramount importance for the development and widespread of electrification in transport modes. In addition to the ongoing evolution and research on novel and better chemistries, the application of sensors and measurement techniques at the battery cell level could foster the electrification process by introducing novel concepts like the Smart Battery. This work presents the Smart Battery paradigm and reviews the state-of-the-art sensor technologies that can be of interest for its development in automotive
An Electrical Impedance Tomography Platform for Tissue Engineering
No full textElectrical Impedance Tomography (EIT) stands out as a promising imaging tool designed for probing the electrical characteristics of tissues, including those within the human body. The affordability, non-invasiveness, and portability of EIT have contributed to its widespread adoption in numerous biomedical applications. However, the effective implementation of EIT demands substantial advancements in both hardware and software domains. Moreover, customization is necessary for every EIT system to suit the specific application of interest. In this paper, an efficient EIT hardware suitable for tissue engineering applications is presented. This analysis focuses on the initial assessment of the system's functionality. In the initial stage, this involves comparing data obtained from simulations with experimental data acquired using resistive mesh phantoms. Subsequently, the validation procedure is further performed by executing the reconstruction of an inclusion within a specially designated tank that has been filled with a saline solution. The system has demonstrated the potential to be employed for future studies as a label-free system for the non-destructive characterization of complex biological processes
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
An integrated DC/DC converter with online monitoring of hot-carrier degradation
Full text linkAn integrated DC/DC converter with online monitoring of the degradation induced by hot-carrier stress (HCD) in new generation power LDMOS transistors is proposed. In particular, when a relatively high drain voltage is applied during on-state regime (switching phase), degradation mechanisms lead to an increase of the transistor on-resistance (RON). To this purpose, the converter is able to dynamically estimate the RON of the power LDMOS and to provide its value to the user during normal operation. The presented solution, developed in STMicroelectronics 90nm BCD technology, features a non-invasive current sensing and voltage sampling architecture, which is applied to a common DC/DC boost converter to evaluate the resistance of the power LDMOS. Without lack of generality, this specific sensing structure can be applied to any kind of converter, e.g. buck or buck-boost, as it does not require any change in the main conversion circuit
Multiband Multisine Excitation Signal for Online Impedance Spectroscopy of Battery Cells
Full text linkMultisine electrochemical impedance spectroscopy (EIS) represents a highly promising technique for the online characterization of battery functional states, offering the potential to monitor, in real-time, key degradation phenomena such as aging, internal resistance variation, and state of health (SoH) evolution. However, its widespread adoption in embedded systems is currently limited by the need to balance measurement accuracy with strict energy constraints and the requirement for short acquisition times. This work proposes a novel broadband EIS approach based on a multiband multisine excitation strategy in which the excitation signal spectrum is divided into multiple sub-bands that are sequentially explored. This enables the available energy to be concentrated on a limited portion of the spectrum at a time, thereby significantly improving the signal-to-noise ratio (SNR) without substantially increasing the total measurement time. The result is a more energy-efficient method that maintains high diagnostic precision. We further investigated the optimal design of these multiband multisine sequences, taking into account realistic constraints imposed by the sensing hardware such as limitations in excitation amplitude and noise level. The effectiveness of the proposed method was demonstrated within a comprehensive simulation framework implementing a complete impedance measurement system. Compared with conventional excitation techniques (i.e., the sine sweep and the classical single-band multisine methods), the proposed strategy is an optimal trade-off solution both in terms of energy efficiency and measurement time. Therefore, the technique is a valuable solution for real-time, embedded, and in situ battery diagnostics, with direct implications for the development of intelligent battery management systems (BMS), predictive maintenance, and enhanced safety in energy storage applications. © 2025 by the authors
Development of a numerical framework for the analysis of a multi-tone EIS measurement system
No full textThis paper describes an integrated co-simulation framework of circuital/behavioural/algorithmic type devoted to the design, simulation, and support to validation of a system of measurement based on electrochemical impedance spectroscopy (EIS) for lithium-ion battery cells. The simulation framework comprises two main parts: a circuital simulator and a numerical environment. It allows the study of a generic system: in particular, it has been applied to analyze an EIS system as a whole without neglecting the effects of the hardware nonidealities on the software algorithm (through a direct connection between the circuital simulator and the numerical environment). A model is implemented inside the circuital simulator, replicating as accurately as possible an existing laboratory prototype devoted to EIS measurements. After the simulation of the prototype, the numerical environment executes an algorithmic elaboration to estimate impedance values for a lithium-ion battery. Throughout several simulations, it is possible to check the non-idealities of the prototype. The simulation framework identified and corrected a malfunction of the prototype available in the laboratory and thus permitted the implementation of a circuit with improved performance
A low-cost Electrochemical Impedance Spectroscopy-based sensor node for online battery cell monitoring
No full textThis paper proposes a proof-of-concept for a low-cost compact battery cell monitoring system based on Electrochemical Impedance Spectroscopy (EIS). The architecture exploits a multisine excitation signal, which reduces the time required for EIS measurement in the frequency range of interest, enabling online battery monitoring/diagnosis. A comprehensive CAD simulation of the system is performed in TINA-TI to evaluate its performance. The simulation covers the analysis of the general behaviour of the entire system and the complete signal elaboration flow, from analog signal processing to digital analysis of the impedance data based on Discrete Fourier Transform (DFT). This allowed for the analysis of the non-ideal effects of the components, as well as the error induced by the DFT algorithm. Moreover, thermal-noise limitation on the resolution of the system is assessed to verify its capability of detecting variations down to 1 mΩ. Finally, the system is tested in the reconstruction of the impedance spectrum of a battery cell described by an integer-order equivalent circuit model, demonstrating good accuracy. The overall system is realized with low-power off-the-shelf components, representing an innovative solution towards the feasibility of an even more integrated sensor node, which will be designed for implementation at cell level for in-operando sensing
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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