Articoli di riviste: "Converter-Based impedance spectroscopy (IS)"

1

Dam, Shimul Kumar, e Vinod John. "High-Resolution Converter for Battery Impedance Spectroscopy". IEEE Transactions on Industry Applications 54, n. 2 (marzo 2018): 1502–12. http://dx.doi.org/10.1109/tia.2017.2771498.

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Namin, Reyhaneh L., e Shahin J. Ashtiani. "Effect of ADC Resolution on Low-Frequency Electrical Time-Domain Impedance Spectroscopy". Metrology and Measurement Systems 24, n. 2 (27 giugno 2017): 425–36. http://dx.doi.org/10.1515/mms-2017-0019.

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AbstractIn this paper, the effect of the resolution of an analogue-to-digital converter (ADC) on the accuracy of timedomain low-frequency electrical impedance spectroscopy is examined. For the first time, we demonstrated that different wideband stimuli signals used for impedance spectroscopy have different sensitivities to the resolution of ADC used in impedance spectroscopy systems. We also proposed Ramp and Half-Gaussian signals as new wideband stimulating signals for EIS. The effect of ADC resolution was studied for Sinc, Gaussian, Half-Gaussian, and Ramp excitation signals using both simulation and experiments. We found that Ramp and Half-Gaussian signals have the best performance, especially at low frequencies. Based on the results, a wideband electrical impedance spectroscopy circuit was implemented with a high accuracy at frequencies bellow 10 Hz.

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Wang, Ke Ning, Heng Zhao e Wei Wang. "Design of a Bioelectrical Impedance Spectrometer Based on AD5933". Applied Mechanics and Materials 239-240 (dicembre 2012): 392–96. http://dx.doi.org/10.4028/www.scientific.net/amm.239-240.392.

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This paper designed a bioelectrical impedance spectroscopy (BIS) measurement system based on the integrated impedance converter AD5933. The working principle of the AD5933 was briefly introduced, and a bipolar BIS measurement device was designed. The AD5933 can be controlled by MCU STC89LE516AD through an I2C bus. The software of the BIS device was written in C51 language and provides a friendly human-machine interface. Preliminary experiment showed that the impedance measurement error at different frequencies is less than 3% and found that the measurement accuracy is relatively high for larger resistor.

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Dam, Shimul Kumar, e Vinod John. "Battery impedance spectroscopy using bidirectional grid connected converter". Sādhanā 42, n. 8 (4 luglio 2017): 1343–54. http://dx.doi.org/10.1007/s12046-017-0686-9.

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Schmidt, Wolfram, Carsten Tautorat, Klaus-Peter Schmitz, Niels Grabow, Frank Kamke, Sylvia Pfensig e Stefan Siewert. "Multi-channel impedance analyzer for automated testing of networks and biomaterials". Current Directions in Biomedical Engineering 6, n. 3 (1 settembre 2020): 414–17. http://dx.doi.org/10.1515/cdbme-2020-3107.

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AbstractImpedance spectroscopy represents a basic operating principle for biomedical sensors, bioimpedance spectroscopy, electrochemical analyses and for characterization of functional biomaterials. For automated long-term investigations, an impedance analyzer for multi-channel testing of up to eight passive two-pole networks is presented in this paper. Its operating system is application-specific adapted to the required test functionalities and measuring ranges. Measurements are based on a commercially available integrated impedance converter circuit. Our current analyzer setup is capable of measuring impedance values from 50 kΩ up to 10 MΩ with automated range selection for most accurate results. The impedance under test is excited with a single frequency of 1 kHz. An impedance accuracy of 1.5 % was determined in reference measurements. The presented impedance analyzer is a low cost system ready for use particularly in long-term characterization of dielectric networks, such as material properties, with multiple samples.

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Chen, Tse-An, Wen-Jui Wu, Chia-Ling Wei, Robert B. Darling e Bin-Da Liu. "Novel 10-Bit Impedance-to-Digital Converter for Electrochemical Impedance Spectroscopy Measurements". IEEE Transactions on Biomedical Circuits and Systems 11, n. 2 (aprile 2017): 370–79. http://dx.doi.org/10.1109/tbcas.2016.2592511.

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7

Arceo-Gómez, David Enrique, Javier Reyes-Trujeque, Patricia Balderas-Hernández, Andrés Carmona-Hernández, Araceli Espinoza-Vázquez, Ricardo Galván-Martínez e Ricardo Orozco-Cruz. "Performance and Surface Modification of Cast Iron Corrosion Products by a Green Rust Converter (Mimosa tenuiflora Extract)". Surfaces 7, n. 1 (13 marzo 2024): 143–63. http://dx.doi.org/10.3390/surfaces7010010.

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One of the alternative materials used for conducting conservation treatment of iron artifacts is the rust converter, since it generates barrier properties and more stable oxides. The protective properties and surface modifications from using Mimosa tenuiflora extract as a green rust converter on a gray iron oxide layer were studied. The surface characterization was carried out using a Scanning Electron Microscope coupled to an energy-dispersive X-ray spectrometer (SEM-EDS), along with infrared spectroscopy (IR), Raman spectroscopy, X-ray Diffraction (XRD), and Water Contact Angle (WCA). Electrochemical characterization was performed with an Electrochemical Impedance Spectroscope (EIS) using 3.5 wt.% NaCl as the electrolyte. According to the results of the Raman spectroscopy and XRD, the layer of corrosion products formed after 90 days in the atmosphere was composed of goethite, lepidocrocite, maghemite, hematite, and magnetite. The surface of the corrosion products was transformed with the rust converter into an amorphous and microcracked layer. By IR, the Fe-O and C-O-Fe bonds associated with the iron chelate were found with absorption bands at 1540 and 1567 cm−1, respectively. By XRD, a modification of the magnetite crystallinity was observed. Finally, the Water Contact Angle and the protective capacity of the corrosion products were improved by the presence of the rust converter.

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Shin, Sounghun, Yoontae Jung, Soon-Jae Kweon, Eunseok Lee, Jeong-Ho Park, Jinuk Kim, Hyung-Joun Yoo e Minkyu Je. "Design of Reconfigurable Time-to-Digital Converter Based on Cascaded Time Interpolators for Electrical Impedance Spectroscopy". Sensors 20, n. 7 (29 marzo 2020): 1889. http://dx.doi.org/10.3390/s20071889.

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This paper presents a reconfigurable time-to-digital converter (TDC) used to quantize the phase of the impedance in electrical impedance spectroscopy (EIS). The TDC in the EIS system must handle a wide input-time range for analysis in the low-frequency range and have a high resolution for analysis in the high-frequency range. The proposed TDC adopts a coarse counter to support a wide input-time range and cascaded time interpolators to improve the time resolution in the high-frequency analysis without increasing the counting clock speed. When the same large interpolation factor is adopted, the cascaded time interpolators have shorter measurement time and smaller chip area than a single-stage time interpolator. A reconfigurable time interpolation factor is adopted to maintain the phase resolution with reasonable measurement time. The fabricated TDC has a peak-to-peak phase error of less than 0.72° over the input frequency range from 1 kHz to 512 kHz and the phase error of less than 2.70° when the range is extended to 2.048 MHz, which demonstrates a competitive performance when compared with previously reported designs.

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9

Li, Wang, Gen Wang Liu e Fu He Yang. "Design of Automatic Measurement System of Lithium Battery Electrochemical Impedance Spectroscopy Based on Microcomputer". Applied Mechanics and Materials 241-244 (dicembre 2012): 259–64. http://dx.doi.org/10.4028/www.scientific.net/amm.241-244.259.

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A system of miniaturized lithium battery electrochemical impedance spectroscopy (EIS) measurement is designed with high precision impedance converter chip AD5933 as its core. The measurement range of the system is from 0.010Hz to 100 KHz. Meanwhile, by using a high-level programming language of C#, an interface is developed which can real-time graphic display of EIS information. Through measurement and analysis of two types of impedance, the results show that detection precision of the system is less than 3.5%. Finally, amplitude-frequency response curves and Nyquist plots of HL-18650 M lithium battery at different state of charge (SOC) levels are measured. Compared with lithium battery EIS measurement system by traditional division, this system has the outstanding advantages of small size, high level of integration, low cost, simple operation and high precision. It is helpful to the mass production and application of lithium battery EIS measurement system.

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Wang, Hanqing, Arnaud Gaillard e Daniel Hissel. "A review of DC/DC converter-based electrochemical impedance spectroscopy for fuel cell electric vehicles". Renewable Energy 141 (ottobre 2019): 124–38. http://dx.doi.org/10.1016/j.renene.2019.03.130.

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Borchani, Fadoua, Souhir Sallem e Mohamed Ben Ali Kammoun. "On-line Electrochemical Impedance Spectroscopy method for PV diagnosis system". E3S Web of Conferences 336 (2022): 00071. http://dx.doi.org/10.1051/e3sconf/202233600071.

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PV fault conditions in photovoltaic (PV) systems reduce panel power performance and accelerate cell degradation. In this way, many research have recently turned to the diagnosis of PV generator to minimize the cost of the produced energy and ensure reliable power production. This paper proposes a new PV diagnosis system based on on-line Electrochemical Impedance Spectroscopy. This latter is used to estimate internal parameters of PV panel connected to a resistive load via a DC/DC boost converter. The Nyquist Diagram allows to plot and evaluate dynamic impedance response versus variable low frequency signal injected in conjunction with the high frequency system allowing to operate the PV in MPPT condition. The dynamic single diode model with a series resistance, a shunt resistance and a junction capacitance is used to design the PV model in MATLAB/Simulink. Simulations results are given for normal and for faulty operation whether in the PV panel or in the load. Referring to these results, it is concluded that the proposed diagnosis method allows to detect PV panel faults regardless of load variation.

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Barylo, Hryhorii, Oksana Boyko, Ihor Helzhynskyy, Roman Holyaka e Tetyana Marusenkova. "Universal hardware and software system of signal converting for integrated sensor devices implementation". Scientific journal of the Ternopil national technical university 100, n. 4 (2020): 106–17. http://dx.doi.org/10.33108/visnyk_tntu2020.04.106.

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The problem of developing a universal signal converter for the construction of integrated sensors in data fusion concept is solved. Considering the requirements of modern microcircuit technique, in particular for sensory devices of the Internet of Things, the signal path of the synthesized sensors is implemented based on PSoC of 5LP Family Cypress. The testing of the developed system was carried out in the process of realization the integrated sensors of thermal analysis, optoelectronics, magnetic tracking and impedance spectroscopy.

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Abareshi, Mohammad, Erfan Sadeghi, Mohsen Hamzeh, Mehrdad Saif e Seyed Mohammad Mahdi Alavi. "Multi-purpose controllable electrochemical impedance spectroscopy using bidirectional DC–DC converter". Journal of Energy Storage 55 (novembre 2022): 105750. http://dx.doi.org/10.1016/j.est.2022.105750.

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Islam, Shekh Md Mahmudul, Mohammad Anisur Rahman Reza e Md Adnan Kiber. "Performances of Multi-Frequency Voltage to Current Converters for Bioimpedance Spectroscopy". Bangladesh Journal of Medical Physics 5, n. 1 (19 aprile 2013): 71–76. http://dx.doi.org/10.3329/bjmp.v5i1.14671.

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Breast cancer is one of the most common diseases affecting women and the mortality rate is very high in Bangladesh, mainly due to the lack of early diagnosis. X-ray mammography is not available widely in Bangladesh, besides it has an associated biological hazard. Multi-frequency bio-impedance measurement or bio-impedance spectroscopy has a great potential in many biomedical applications including breast cancer screening which involves tissue characterization. In Bio-impedance spectroscopy a range of frequencies of low level current is injected to the human body and corresponding bio-impedance is measured. In a typical bio-impedance measurement system an ac source with a constant current amplitude is an essential part in which the current amplitude should not change with frequency or load, the latter being typically of the order of a few kilo ohms in the human body. The constant current source is usually obtained from a voltage-to-current converter and several standard designs are available, for example a floating current source, a Howland current source and an enhanced Howland current source. The present work was taken up to perform a comparative study of these three types of current sources based on a commonly available low cost operational amplifier, 741. It was found that the enhanced Howland current source gave the best performance, the current being almost constant up to a frequency of about 10kHz for a load of 10k?. This work gives an understanding of this fundamental circuit segment that is essential for the development of a Bioimpedance Spectroscopy system. DOI: http://dx.doi.org/10.3329/bjmp.v5i1.14671 Bangladesh Journal of Medical Physics Vol.5 No.1 2012 71-76

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Basak, Rinku, Khan A. Wahid e Anh Dinh. "Estimation of the Chlorophyll-A Concentration of Algae Species Using Electrical Impedance Spectroscopy". Water 13, n. 9 (28 aprile 2021): 1223. http://dx.doi.org/10.3390/w13091223.

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Algae are a significant component of a biological monitoring program in an aquatic ecosystem. They are ideally suited for water quality assessments because of their nutrient requirements, rapid reproduction rate, and very short life cycle. Algae composition and temporal variation in abundances are important in determining the trophic level of lakes, and those can be estimated by the Chlorophyll-a (Chl-a) concentration of the species. In this work, a non-destructive method was employed to estimate the Chlorophyll-a concentration of multiple algae species using electrical impedance spectroscopy (EIS). The proposed EIS method is rapid, cheaper, and suitable for in situ measurements compared with the other available non-destructive methods, such as spectrophotometry and hyperspectral or multispectral imaging. The electrical impedances in different frequencies ranging from 1 to 100 kHz were observed using an impedance converter system. Significant observations were identified within 3.5 kHz for multiple algae species and therefore reported in the results. A positive correlation was found between the Chlorophyll-a and the measured impedance of algae species at different frequencies. Later, EIS models were developed for the species in 1–3.5 kHz. A correlation of 90% was found by employing a least squares method and multiple linear regression. The corresponding coefficients of determination were obtained as 0.9, 0.885, and 0.915, respectively for 49 samples of Spirulina, 41 samples of Chlorella, and 26 samples of mixed algae species. The models were later validated using a new and separate set of samples of algae species.

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Polom, Timothy A., Markus Andresen, Marco Liserre e Robert D. Lorenz. "Frequency-Domain Electrothermal Impedance Spectroscopy of an Actively Switching Power Semiconductor Converter". IEEE Transactions on Industry Applications 55, n. 6 (novembre 2019): 6161–72. http://dx.doi.org/10.1109/tia.2019.2930031.

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Baert, B., O. Nakatsuka, S. Zaima e N. D. Nguyen. "Impedance Spectroscopy of GeSn-based Heterostructures". ECS Transactions 50, n. 9 (15 marzo 2013): 481–90. http://dx.doi.org/10.1149/05009.0481ecst.

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Yin, Hong-Run, Ming Ye, Yang Wu, Kai Liu, Hua-Ping Pan e Jia-Feng Yao. "Biological tissue detection based on electrical impedance spectroscopic tomograsphy". Acta Physica Sinica 71, n. 4 (2022): 048706. http://dx.doi.org/10.7498/aps.71.20211600.

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A bioimpedance spectroscopic imaging method for detecting the biological tissue based on electrical impedance tomography (EIT) and bioimpedance spectroscopy (BIS) is proposed. This method visualizes the target area and accurately recognizes the target type, which can be used for detecting the early lung cancer, assist clinicians in accurately detecting the early lung cancer, and improving the cure rate of early lung cancer. In this paper the bioimpedance spectroscopic imaging method is verified to be feasible and effective in detecting the early lung cancer through numerical simulation. The simulation results show that 1) the bioimpedance spectroscopic imaging method can realize the visualization of the early lung cancer area and accurately distinguish the type of early lung cancer, and 2) the optimal number of acquisitions of impedance spectroscopy is 4, and the best classifier is Linear-SVM, and the average classification accuracy of 5-fold cross-validation can reach 99.9%. In order to verify the simulation results, three biological tissues with different electrical characteristics are selected to simulate cancerous regions used for detection. The experimental results show that the method can visualize the biological tissue area and distinguish the type of biological tissue. This method can integrate the advantages of electrical impedance imaging and bioimpedance spectroscopy, and is very promising way of detecting early lung cancer.

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Zhou, Jialong, Jinhai Jiang, Fulin Fan, Chuanyu Sun, Zhen Dong e Kai Song. "Real-Time Impedance Detection for PEM Fuel Cell Based on TAB Converter Voltage Perturbation". Energies 17, n. 17 (29 agosto 2024): 4320. http://dx.doi.org/10.3390/en17174320.

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Fuel cells, as clean and efficient energy conversion devices, hold great potential for applications in the fields of hydrogen-based transportation and stand-alone power systems. Due to their sensitivity to load parameters, environmental parameters, and gas supply, the performance monitoring and fault diagnosis of fuel cell systems have become crucial research areas. Electrochemical impedance spectroscopy (EIS) is a widely applied analytical method in fuel cell systems. that can provide rich information about dynamic system responses, internal impedance, and transmission characteristics. Currently, EIS detection is primarily implemented by using simple topologies such as boost circuits. However, the injection of excitation signals often results in significant power fluctuations, leading to issues such as uneven temperature distributions within the cell, unstable gas supply, and damage to the proton exchange membrane. To address this issue, this paper proposes a real-time EIS detection technique for a proton exchange membrane fuel cell (PEMFC) system that connects a lithium-ion battery and injects the load voltage perturbation through a triple active bridge (TAB) converter. By applying the small-signal model of the TAB converter and designing a system controller using a decoupling control method, the PEMFC power remains stable after the disturbance injection across the entire frequency range under tests. Furthermore, the lithium-ion battery can instantly track load changes during fluctuations. The proposed EIS detection method can acquire EIS data in real time to monitor the state of the PEMFC. Simulation results validate the effectiveness and accuracy of the proposed method for EIS detection.

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Radogna, Antonio Vincenzo, Simonetta Capone, Luca Francioso, Pietro Aleardo Siciliano e Stefano D’Amico. "A 177 ppm RMS Error-Integrated Interface for Time-Based Impedance Spectroscopy of Sensors". Electronics 11, n. 22 (19 novembre 2022): 3807. http://dx.doi.org/10.3390/electronics11223807.

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This paper presents an integrated circuit for time-based electrical impedance spectroscopy (EIS) of sensors. The circuit exploits maximum-length sequences (MLS) in order to perform a broadband excitation of the sensors under test. Therefore, the measured time-domain EIS is obtained by cross-correlating the input with the output of the analog front end (AFE). Unlike the conventional digital approach, the cross-correlation operation is performed in the analog domain. This leads to a lower RMS error in the measured time-domain EIS since the signal processing is not affected by the quantization noise of the analog-to-digital converter (ADC). It also relaxes the sampling frequency of the ADC leading, along with the lack of random access memory (RAM) usage, to a reduced circuit complexity. Theoretical concepts about the circuit’s design and operation are presented, with an emphasis on the thermal noise phenomenon. The simulated performances are shown by testing a sensor’s equivalent model composed of a 50 kΩ resistor in parallel with a 100 pF capacitor. A time-based EIS output of 255 points was obtained with a maximum tested frequency of 500 kHz and a simulated RMS error of 0.0177% (or 177 ppm).

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Zhang, Bin Bin, Guan Hua Wu, Сhao Bo Chen e Song Gao. "Solid Propellant Aging Detection Method Based on Impedance Spectroscopy". Advanced Materials Research 1179 (31 gennaio 2024): 133–44. http://dx.doi.org/10.4028/p-hnkn3r.

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Aiming at the shortcomings of large volume, high cost and long detection cycle of traditional solid propellant aging detection methods, a solid propellant aging detection method based on impedance spectroscopy is proposed. Firstly, the internal impedance of the solid propellant changes after aging, and a portable solid propellant impedance spectrum acquisition system based on impedance spectroscopy is designed based on the principle of electrochemical impedance spectroscopy, and the real and imaginary parts of the impedance spectrum are obtained. Secondly, in order to reduce the data dimension of the classification algorithm, the KPCA (Nuclear Principal Component Analysis) feature extraction algorithm is used to extract the impedance spectrum features of the solid propellant. Then, according to the impedance spectrum characteristics, the BP neural network is used for classification training, and the correspondence between the impedance spectrum and the aging time is obtained. Finally, the feasibility and effectiveness of the proposed method are verified on the physical platform, and the results show that the proposed method has the advantages of high precision and accurate classification, and can effectively predict the aging degree of solid propellant.

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Schüler, M., T. Sauerwald e A. Schütze. "Metal oxide semiconductor gas sensor self-test using Fourier-based impedance spectroscopy". Journal of Sensors and Sensor Systems 3, n. 2 (25 settembre 2014): 213–21. http://dx.doi.org/10.5194/jsss-3-213-2014.

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Abstract. For the self-test of semiconductor gas sensors, we combine two multi-signal processes: temperature-cycled operation (TCO) and electrical impedance spectroscopy (EIS). This combination allows one to discriminate between irreversible changes of the sensor, i.e., changes caused by poisoning, as well as changes in the gas atmosphere. To integrate EIS and TCO, impedance spectra should be acquired in a very short time period, in which the sensor can be considered time invariant, i.e., milliseconds or less. For this purpose we developed a Fourier-based high-speed, low-cost impedance spectroscope. It provides a binary excitation signal through an FPGA (field programable gate array), which also acquires the data. To determine impedance spectra, it uses the ETFE (empirical transfer function estimate) method, which calculates the impedance by evaluating the Fourier transformations of current and voltage. With this approach an impedance spectrum over the range from 61 kHz to 100 MHz is acquired in ca. 16 μs. We carried out TCO–EIS measurements with this spectroscope and a commercial impedance analyzer (Agilent 4294A), with a temperature cycle consisting of six equidistant temperature steps between 200 and 450 °C, with lengths of 30 s (200 °C) and 18 s (all others). Discrimination of carbon monoxide (CO) and methane (CH4) is possible by LDA (linear discriminant analysis) using either TCO or EIS data, thus enabling a validation of results by comparison of both methods.

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Manjunath, Manjunath, Simon Hausner, André Heine, Patrick De Baets e Dieter Fauconnier. "Electrical Impedance Spectroscopy for Precise Film Thickness Assessment in Line Contacts". Lubricants 12, n. 2 (10 febbraio 2024): 51. http://dx.doi.org/10.3390/lubricants12020051.

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In this article, we focus on utilising electrical impedance spectroscopy (EIS) for the assessment of global and contact impedances in roller bearings. Our primary objective is to establish a quantitative prediction of lubricant film thickness in elasto-hydrodynamic lubrication (EHL) and investigate the impedance transition from ohmic to capacitive behaviour as the system shifts from boundary lubrication to EHL. To achieve this, we conduct measurements of electrical impedance, bearing and oil temperature, and frictional torque in a cylindrical roller thrust bearing (CRTB) subjected to pure axial loading across various rotational speeds and supply oil temperatures. The measured impedance data is analysed and translated into a quantitative measure of lubricant film thickness within the contacts using the impedance-based and capacitance-based methods. For EHL, we observe that the measured capacitance of the EHL contact deviates from the theoretical value based on a Hertzian contact shape by a factor ranging from 3 to 11, depending on rotational speed, load, and temperature. The translation of complex impedance values to film thickness, employing the impedance and capacitance method, is then compared with the analytically estimated film thickness using the Moes correlation, corrected for inlet shear heating effects. This comparison demonstrates a robust agreement within 2% for EHL film thickness measurement. Monitoring the bearing resistance and capacitance via EIS across rotational speeds clearly shows the transition from boundary to mixed lubrication as well as the transition from mixed lubrication to EHL. Finally, we have observed that monitoring the electrical impedance appears to have the potential to perform the run-in of bearings in a controlled way.

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Varnosfaderani, Mina Abedi, e Dani Strickland. "Online impedance spectroscopy estimation of a dc–dc converter connected battery using a switched capacitor-based balancing circuit". Journal of Engineering 2019, n. 7 (1 luglio 2019): 4681–85. http://dx.doi.org/10.1049/joe.2018.8069.

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Allison, Andrew L., Loriann M. Clark, William D. Howell e William L. Sexton. "Arduino-based Impedance Spectroscopy: An Open-source Platform For Physiological Impedance Spectroscopy Measurements In Rats". Medicine & Science in Sports & Exercise 52, n. 7S (luglio 2020): 891. http://dx.doi.org/10.1249/01.mss.0000685220.55798.4a.

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Ivanisevic, Nikola, Saul Rodriguez e Ana Rusu. "Impedance Spectroscopy Based on Linear System Identification". IEEE Transactions on Biomedical Circuits and Systems 13, n. 2 (aprile 2019): 396–402. http://dx.doi.org/10.1109/tbcas.2019.2900584.

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Kandukuri, Tharun Reddy, Ioannis Prattis, Pelumi Oluwasanya e Luigi G. Occhipinti. "Pathogen Detection via Impedance Spectroscopy-Based Biosensor". Sensors 24, n. 3 (28 gennaio 2024): 856. http://dx.doi.org/10.3390/s24030856.

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This paper presents the development of a miniaturized sensor device for selective detection of pathogens, specifically Influenza A Influenza virus, as an enveloped virus is relatively vulnerable to damaging environmental impacts. In consideration of environmental factors such as humidity and temperature, this particular pathogen proves to be an ideal choice for our study. It falls into the category of pathogens that pose greater challenges due to their susceptibility. An impedance biosensor was integrated into an existing platform and effectively separated and detected high concentrations of airborne pathogens. Bio-functionalized hydrogel-based detectors were utilized to analyze virus-containing particles. The sensor device demonstrated high sensitivity and specificity when exposed to varying concentrations of Influenza A virus ranging from 0.5 to 50 μg/mL. The sensitivity of the device for a 0.5 μg/mL analyte concentration was measured to be 695 Ω· mL/μg. Integration of this pathogen detector into a compact-design air quality monitoring device could foster the advancement of personal exposure monitoring applications. The proposed sensor device offers a promising approach for real-time pathogen detection in complex environmental settings.

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Karlash, A. Yu. "Impedance spectroscopy of composites based on porous silicon and silica aerogel for sensor applications". Functional Materials 20, n. 1 (25 marzo 2013): 68–74. http://dx.doi.org/10.15407/fm20.01.068.

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Tohmyoh, Hironori, Takuya Imaizumi e Masumi Saka. "Measurement of Acoustic Impedance of Thin Polymeric Films by Acoustic Resonant Spectroscopy". Key Engineering Materials 353-358 (settembre 2007): 2349–52. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.2349.

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An acoustic resonant spectroscopy technique for measuring the acoustic impedance of micron-scale polymer films without knowing any values of ultrasonic velocity, thickness and density has been developed. The method, which is based on spectral analysis, observes the acoustic resonance between water, the film and a tungsten plate with high acoustic impedance. The acoustic impedances of poly(vinyl chloride), poly(vinyl alcohol) and nylon films are determined by the spectroscopy technique. Moreover, the values of ultrasonic velocity and density of the films are also determined from the resonance frequencies of the films.

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Parache, François, Henri Schneider, Christophe Turpin, Nicolas Richet, Olivier Debellemanière, Éric Bru, Anh Thao Thieu, Caroline Bertail e Christine Marot. "Impact of Power Converter Current Ripple on the Degradation of PEM Electrolyzer Performances". Membranes 12, n. 2 (19 gennaio 2022): 109. http://dx.doi.org/10.3390/membranes12020109.

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In this study, an endurance test of 3000 h was conducted on four equivalent proton exchange membrane (PEM) electrolyzers to identify and quantify the impact of an electric ripple current on their durability. Three different typical power converter waveforms and frequencies were explored. Signals were added to the same direct current carrier and also tested for reference. Performance comparison based on polarization curves and electrochemical impedance spectroscopy (EIS) analysis revealed that the ripple current favors degradation. Triangular waveform and a frequency of 10 kHz were identified as the most degrading conditions, leading to a sharp increase in high-frequency resistance (HFR) and the emergence of mass transport limitations due to the enhanced degradation of titanium mesh. Moreover, reversible losses were observed and further explorations are needed to decorrelate them from our observations.

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Depernet, Daniel, Abdellah Narjiss, Frédéric Gustin, Daniel Hissel e Marie-Cécile Péra. "Integration of electrochemical impedance spectroscopy functionality in proton exchange membrane fuel cell power converter". International Journal of Hydrogen Energy 41, n. 11 (marzo 2016): 5378–88. http://dx.doi.org/10.1016/j.ijhydene.2016.02.010.

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32

Yamaguchi, Tomiharu, e Akinori Ueno. "Capacitive-Coupling Impedance Spectroscopy Using a Non-Sinusoidal Oscillator and Discrete-Time Fourier Transform: An Introductory Study". Sensors 20, n. 21 (9 novembre 2020): 6392. http://dx.doi.org/10.3390/s20216392.

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In this study, we propose a new short-time impedance spectroscopy method with the following three features: (1) A frequency spectrum of complex impedance for the measured object can be obtained even when the measuring electrodes are capacitively coupled with the object and the precise capacitance of the coupling is unknown; (2) the spectrum can be obtained from only one cycle of the non-sinusoidal oscillation waveform without sweeping the oscillation frequency; and (3) a front-end measuring circuit can be built, simply and cheaply, without the need for a digital-to-analog (D-A) converter to synthesize elaborate waveforms comprising multiple frequencies. We built the measurement circuit using the proposed method and then measured the complex impedance spectra of 18 resistive elements connected in series with one of three respective capacitive couplings. With this method, each element’s resistance and each coupling’s capacitance were estimated independently and compared with their nominal values. When the coupling capacitance was set to 10 nF or 1.0 nF, estimated errors for the resistive elements in the range of 2.0–10.0 kΩ were less than 5%.

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33

Li, Gen, Jie Chen, Hongze Li, Libin Hu, Wenjun Zhou, Chengke Zhou e Mingzhen Li. "Diagnosis and Location of Power Cable Faults Based on Characteristic Frequencies of Impedance Spectroscopy". Energies 15, n. 15 (2 agosto 2022): 5617. http://dx.doi.org/10.3390/en15155617.

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Power cable condition diagnosis and deterioration location rely on signatures of aging characteristics which precede the final breakdown. The purpose of this study was to investigate how to diagnose and locate the aging and/or deterioration of power cables through the analysis of the impedance spectroscopy. The concepts of the reference frequency and characteristic frequency of cable impedance spectroscopy are defined for the first time. Based on the reference frequency, the optimal frequency range for analysis of impedance spectroscopy can be determined, whilst based on characteristic frequency, a set of criteria for assessing cable conditions are examined and established. The solution proposed in this paper has the advantage of being easier to implement than the previously reported “broadband” impedance spectroscopy methods, as it helps to reduce the frequency range for measurement instrumentations; the proposed method also does not need the measurements of the parameters of the cable being tested.

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34

Yang, Yuxiang, He Bian, Fangling Du, Qiang Sun e He Wen. "Development of a Stair-Step Multifrequency Synchronized Excitation Signal for Fast Bioimpedance Spectroscopy". BioMed Research International 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/143461.

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Wideband excitation signal with finite prominent harmonic components is desirable for fast bioimpedance spectroscopy (BIS) measurements. This work introduces a simple method to synthesize and realize a type of periodical stair-step multifrequency synchronized (MFS) signal. The Fourier series analysis shows that thep-order MFS signalf(p,t)has constant 81.06% energy distributed equally on itsp 2nth primary harmonics. The synthesis principle is described firstly and then two examples of the 4-order and 5-order MFS signals,f(4,t)andf(5,t), are synthesized. The method to implement the MFS waveform based on a field-programmable gate array (FPGA) and a digital to analog converter (DAC) is also presented. Both the number and the frequencies of the expected primary harmonics can be adjusted as needed. An impedance measurement experiment on a RC three-element equivalent model is performed, and results show acceptable precision, which validates the feasibility of the MFS excitation.

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35

Syarif, Nirwan, Nurlisa Hidayanti, Edy Herianto Majlan e Monica Sari Jayanti. "Electrochemical Impedance Spectroscopy of Polyvinylalcohol Based Gel Electrolyte". Indonesian Journal of Fundamental and Applied Chemistry 2, n. 1 (6 marzo 2017): 16–21. http://dx.doi.org/10.24845/ijfac.v2.i1.16.

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36

Ižák, Tibor, Ondrej Szabó, Lucie Bačáková e Alexander Kromka. "Diamond Functional Layers for Cell-based Impedance Spectroscopy". Procedia Engineering 168 (2016): 614–17. http://dx.doi.org/10.1016/j.proeng.2016.11.227.

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37

Reis, F. T., L. F. Santos, R. M. Faria e D. Mencaraglia. "Temperature dependent impedance spectroscopy on polyaniline based devices". IEEE Transactions on Dielectrics and Electrical Insulation 13, n. 5 (ottobre 2006): 1074–81. http://dx.doi.org/10.1109/tdei.2006.1714932.

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38

Reis, Santos, Faria e Mencaraglia. "Temperature dependent impedance spectroscopy on polyaniline based devices". IEEE Transactions on Dielectrics and Electrical Insulation 13, n. 5 (ottobre 2006): 1074–81. http://dx.doi.org/10.1109/tdei.2006.247834.

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39

Cho, Sungbo, e Hagen Thielecke. "Micro hole-based cell chip with impedance spectroscopy". Biosensors and Bioelectronics 22, n. 8 (15 marzo 2007): 1764–68. http://dx.doi.org/10.1016/j.bios.2006.08.028.

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40

Hasegawa, Yasuhiro, Ryoei Homma e Mioko Ohtsuka. "Thermoelectric Module Performance Estimation Based on Impedance Spectroscopy". Journal of Electronic Materials 45, n. 3 (29 dicembre 2015): 1886–93. http://dx.doi.org/10.1007/s11664-015-4271-x.

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41

Ramanavicius, A., A. Finkelsteinas, H. Cesiulis e A. Ramanaviciene. "Electrochemical impedance spectroscopy of polypyrrole based electrochemical immunosensor". Bioelectrochemistry 79, n. 1 (agosto 2010): 11–16. http://dx.doi.org/10.1016/j.bioelechem.2009.09.013.

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42

Bifano, Luca, Marco Weider, Alice Fischerauer, Gotthard Wolf e Gerhard Fischerauer. "In situ monitoring of used-sand regeneration in foundries by impedance spectroscopy". Journal of Sensors and Sensor Systems 11, n. 2 (11 ottobre 2022): 287–98. http://dx.doi.org/10.5194/jsss-11-287-2022.

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Abstract. This work deals with the impedimetric monitoring of used-sand regeneration in the foundry industry. During the regeneration of used sand, a quartz sand similar to new sand is produced from already used molding and core sand, which especially serves to produce new cores. We explore whether the regeneration progress can be assessed in situ based on measured impedance spectra and their features. The impedances of plate capacitors filled with different typical used-sand mixtures, consisting of quartz sand, coal dust, and bentonite, were repeatedly measured in a frequency range from 500 Hz to 1 MHz. The reproducibility of the measurements proved to be sufficient for practical applications. The mean impedances were plotted in Nyquist diagrams. From these plots, systematic impedance–composition correlations could be determined for two of the three component systems. Conclusions about the regeneration state could be drawn from the impedance curves by introducing various features. These were the median, the mean, and the standard deviation of the frequency-dependent resistance and reactance. With these indicators, it was then possible to establish one-to-one relations between the material composition of the molding materials and the impedance measurement. In field measurements on regenerated used sands, this observation was confirmed, and the regeneration progress was observed on the basis of the impedimetrically determined characteristic data.

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43

Shen, Jiabin, e Jiacheng Wang. "Analysis of dc link oscillations in a hybrid fuel cell powertrain brought by in situ converter based electrochemical impedance spectroscopy". International Journal of Hydrogen Energy 45, n. 55 (novembre 2020): 31080–90. http://dx.doi.org/10.1016/j.ijhydene.2020.08.146.

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44

Stevic, Zoran, e Mirjana Rajcic-Vujasinovic. "System for electrochemical investigations based on a PC and the Lab VIEW package". Chemical Industry 61, n. 1 (2007): 1–6. http://dx.doi.org/10.2298/hemind0701001s.

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This paper describes an electrochemical research system based on the Lab VIEW computer software package. An overview of well known electrochemical methods, such as potential measurements, chronopotentiometry, chronoamperometry, cyclic voltammetry and EIS is given. Electrochemical impedance spectroscopy has been adapted for systems containing large capacitances. For signal generation and recording of the response of the investigated electrochemical cell, a measurement and control system was developed, based on a PC P4 computer. The rest of the hardware consists of a commercially available AD-DA converter and an external interface for analog signal processing. The interface is a result of the authors own research. The software platform for the desired measurement methods is Lab VIEW package, which is regarded as a high standard in the area of modern virtual instruments. The developed system was adjusted, tested and compared with other commercially available systems. One such system is in constant use at the Technical Faculty in Bor.

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45

Wang, Hanqing, Arnaud Gaillard e Daniel Hissel. "Online electrochemical impedance spectroscopy detection integrated with step-up converter for fuel cell electric vehicle". International Journal of Hydrogen Energy 44, n. 2 (gennaio 2019): 1110–21. http://dx.doi.org/10.1016/j.ijhydene.2018.10.242.

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46

Cheon, Song-I., Soon-Jae Kweon, Youngin Kim, Jimin Koo, Sohmyung Ha e Minkyu Je. "An Impedance Readout IC with Ratio-Based Measurement Techniques for Electrical Impedance Spectroscopy". Sensors 22, n. 4 (17 febbraio 2022): 1563. http://dx.doi.org/10.3390/s22041563.

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This paper presents an error-tolerant and power-efficient impedance measurement scheme for bioimpedance acquisition. The proposed architecture measures the magnitude and the real part of the target complex impedance, unlike other impedance measurement architectures measuring either the real/imaginary components or the magnitude and phase. The phase information of the target impedance is obtained by using the ratio between the magnitude and the real components. This can allow for avoiding direct phase measurements, which require fast, power-hungry circuit blocks. A reference resistor is connected in series with the target impedance to compensate for the errors caused by the delay in the sinusoidal signal generator and the amplifier at the front. Moreover, an additional magnitude measurement path is connected to the reference resistor to cancel out the nonlinearity of the proposed system and enhance the settling speed of the low-pass filter by a ratio-based detection. Thanks to this ratio-based detection, the accuracy is enhanced by 30%, and the settling time is improved by 87.7% compared to the conventional single-path detection. The proposed integrated circuit consumes only 513 μW for a wide frequency range of 10 Hz to 1 MHz, with the maximum magnitude and phase errors of 0.3% and 2.1°, respectively.

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47

Abdullah, Huda, Norshafadzila Mohammad Naim, Noor Azwen Noor Azmy e Aidil Abdul Hamid. "PANI-Ag-Cu Nanocomposite Thin Films Based Impedimetric Microbial Sensor for Detection ofE. coliBacteria". Journal of Nanomaterials 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/951640.

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PANI-Ag-Cu nanocomposite thin films were prepared by sol-gel method and deposited on the glass substrate using spin coating technique. Polyaniline was synthesized by chemical oxidative polymerization of aniline monomer in the presence of nitric acid. The films were characterized using XRD, FTIR, and UV-Visible spectroscopy. The performance of the sensor was conducted using electrochemical impedance spectroscopy to obtain the change in impedance of the sensor film before and after incubation withE. colibacteria in water. The peaks in XRD pattern confirm the presence of Ag and Cu nanoparticles in face-centered cubic structure. FTIR analysis shows the stretching of N–H in the polyaniline structure. The absorption band from UV-Visible spectroscopy shows high peaks between 400 nm and 500 nm which indicate the presence of Ag and Cu nanoparticles, respectively. Impedance analysis indicates that the change in impedance of the films decreases with the presence ofE. coli. The sensitivity onE. coliincreases for the sample with high concentration of Cu.

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48

Alaka, Panda, e Ramanujan Govindaraj. "Complex Dielectric and Impedance Spectroscopic Studies in a Multiferroic Composite of Bi2Fe4O9-BiFeO3". Condensed Matter 3, n. 4 (2 dicembre 2018): 44. http://dx.doi.org/10.3390/condmat3040044.

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Complex dielectric and impedance spectroscopic studies have been carried out in a detailed manner on the system comprising of Bi2Fe4O9-BiFeO3 composite particles dispersed in a α-Fe2O3 matrix as prepared using ball milling and controlled annealing treatments. This multiferroic composite is observed to exhibit a giant dielectric constant associated with a low tangent loss. A non-Debye type of relaxation has been deduced based on complex modulus analysis. Based on these studies, the important role played by bismuth ferrite nanoshell in the core-shell composite of Bi2Fe4O9-BiFeO3 is elucidated for the observed complex impedance spectroscopic properties of the system. Electron hopping across Fe2+/Fe3+ and oxygen vacancies are deduced to be playing an important role in conduction mechanisms based on activation energy analysis of the complex impedance spectroscopy results.

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49

SHARMA, DHANANJAY K., RAJU KUMAR, RADHESHYAM RAI, SEEMA SHARMA e ANDREI L. KHOLKIN. "IMPEDANCE AND MODULUS SPECTROSCOPY CHARACTERIZATION OF SODIUM-BISMUTH TITANATE-BASED LEAD-FREE FERROELECTRIC MATERIALS". Journal of Advanced Dielectrics 02, n. 01 (gennaio 2012): 1250002. http://dx.doi.org/10.1142/s2010135x12500026.

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In this paper, we present impedance spectroscopy of Sodium Bismuth Titanate-based materials belonging to (1-x) Na 1/2 Bi 1/2 TiO 3-x BaTiO 3(x = 0.04) (NBT–BT) system. NBT–BT ceramics are prepared by high temperature solid-state reaction method. X-ray diffraction technique showed single-phase polycrystalline sample with an ABO3 perovskite structure. Dielectric behavior and the impedance relaxation were investigated in a wide range of temperature (room temperature (RT) –500°C) and frequency (1 kHz–1 MHz). A broad dielectric constant peak was observed over a wide temperature range around the phase transition temperature. The complex impedance plot exhibited one impedance semicircle identified over the frequency range of 1 kHz–1 MHz, which is explained by the grain effect of the bulk. The centers of the impedance semicircles lie below the real axis, which indicates that the impedance response is a Cole–Cole type relaxation.

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50

Li, Yang, Nan Wang, Li-Feng Fan, Yong-Qian Wang, Peng-Fei Zhao, Lan Huang e Zhong-Yi Wang. "A fast approach to determine excitation eigenfrequencies for TD-EIT and FD-EIT". Measurement Science and Technology 34, n. 10 (3 luglio 2023): 105501. http://dx.doi.org/10.1088/1361-6501/acdff3.

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Abstract Electrical impedance tomography can reconstruct the complex conductivity distribution by injecting a current or voltage at a specific frequency into the target domain. The complex conductivity spectroscopy of numerous biological tissues is frequency-dependent. A suitable excitation frequency is vital to high-quality imaging over a wide frequency range. This paper investigates the relationship between the parameters of the biological tissue impedance model and the impedance spectroscopy. A frequency selection method based on the impedance spectroscopy is proposed, in which the impedance spectroscopy on a specific electrode at the domain boundary to be measured is first scanned. In TD-EIT, the difference between the target’s impedance spectroscopy and the null field is calculated, and the frequency corresponding to its extreme value is used as the excitation signal for TD-EIT. The excitation frequency in FD-EIT is the frequency corresponding to the extreme point in the target impedance spectroscopy, and we have also used this method to image the interior of the maize ear. This study provides a quick and efficient method for determining the excitation frequency for EIT, allowing researchers to find the best excitation frequency for high-quality imaging during actual measurements.

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