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- impedance spectroscopy
- molten-salt
- conductivity
- Ba0.97La0.02Ti1-xNb4x/5O3
- EIS spectrum
- Warburg element
- blocking electrodes
- liquid crystals
- electric conductivity
- Signal-to-Noise Ratio (SNR)
- Optoelectronic Information Science and Engineering
- Materials Science and Engineering
- South Ural State University
- Université de Monastir
- Majmaah University
- University of Northumbria
- Université de Sousse
- Gabes University
- Technical University of Darmstadt
- University of Huddersfield
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Structure–Activity/Stability Correlations from the Electrochemical Dynamic Responses of Titanium Anode Coatings Formed of Ordered TiO <sub/>2</sub> @RuO <sub/>2</sub> Microspheres
摘要： Spherical TiO2/RuO2 particles were synthesized by ultrasonic spray pyrolysis (USP) at 200 and 800?C. The activity for the oxygen and chlorine evolution reactions (OER and CER, respectively) and the dynamic responses from electrochemical impedance spectroscopy (EIS) of the USP powders, as well as of the corresponding coatings on Ti, were analyzed and are discussed. The loss of coating activity is discussed with respect to the differences in the EIS and cyclic voltammetry responses of the coatings in their active and inactive states. The 800?C-USP sample was found to be more active than the 200?C-USP sample for both the CER and the OER, whereas the stability of the former was considerably lower. The correlation between the structure, composition and morphology of the powder and the coating with the registered electrochemical properties is discussed. The EIS analysis of the coating resistance distributions induced by the thermal treatment of the powder indicated a complex combination of the pore resistance and the pseudocapacitive charge transfer resistance. An additional coating resistance, due to loose grain boundaries, was introduced into the coatings in their active and inactive state. The EIS analysis indicated the changes in TiO2-enriched core/RuO2-enriched shell structure, caused by the USP temperature.
关键词： TiO2/RuO2,cyclic voltammetry,electrochemical impedance spectroscopy,oxygen evolution reaction,chlorine evolution reaction,ultrasonic spray pyrolysis,coating stability
更新于2025-09-11 14:15:04
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Influence of cadmium precursor concentrations on the structural, optical and electrochemical impedance properties of CdZnS thin films
摘要： Thin films of cadmium zinc sulfide (CdZnS) were deposited on microscopic glass substrates using the chemical bath deposition method and the effects of the Cd precursor concentrations on the morphological, structural and optical properties of the films were studied. The surface morphology as revealed by scanning electron microscope showed closely packed nano particles randomly spread on the surface of the glass substrates. The x-ray diffraction studies showed that the thin films were polycrystalline and the crystallite size decreased with increase in the concentration of the Cd precursor. While the optical absorbance decreased, the bandgap energy increased as the concentration of the cadmium source increased. Electrochemical studies were performed by cyclic voltammetry analysis and impedance measurements at low frequency ranges. Simulation model on the impedance model was carried out to obtain a more quantitative analysis of the data. The ternary CdZnS thin film developed in this work could be useful as window layer in solar cell fabrication.
关键词： electrochemical impedance properties,optical properties,chemical bath deposition,structural properties,CdZnS thin films,cadmium precursor concentrations
更新于2025-09-11 14:15:04
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[IEEE 2018 IEEE 2nd International Conference on Circuits, System and Simulation (ICCSS) - Guangzhou, China (2018.7.14-2018.7.16)] 2018 IEEE 2nd International Conference on Circuits, System and Simulation (ICCSS) - Application of an Infinite Gain Multiple Feedback Filter in VLC Link Range Extension
摘要： This paper presents a visible light communication (VLC) link range extension, achieved by establishing a VLC system using simple, low-cost, and reliable electronic circuitry, and employing a design of a highly resonant frequency selective active band pass filter (infinite gain multiple feedback filter) at the receiver section of the system. The filter was designed for a specific center (resonant) frequency with high Quality factor and gain. An outline of the relationship between Signal-to-Noise ratio (SNR) and transmission distance for three different center frequencies was presented. Results show that by utilizing an IGMF filter at the receiver, a signal-to- noise ratio above 10dB at a distance beyond 1.5 meters can be achieved without any form of lensing at either the transmitter or receiver.
关键词： Signal-to-Noise Ratio (SNR),Infinite Gain Multiple Feedback (IGMF),Visible Light Communications (VLC),LED,Trans-Impedance Amplifier (TIA)
更新于2025-09-10 09:29:36
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Investigation of thermal and electrical properties of As–Se glasses modified with Cu using DSC and AC impedance spectroscopy
摘要： Investigations of thermal properties of CuxAs50Se50 ? x chalcogenides were carried out using a differential scanning calorimeter. It was established that copper introduction significantly affects the complexity of structural network. This was indicated by double-stage crystallization process in the compound Cu15As50Se35. Besides α relaxation, all the glasses during heating show β relaxation. The complexity of the network influences the conductivity values and transport properties in a way of higher DC and AC conductivity for the compound with the highest Cu share. Impedance spectra show two semicircles, indicating the existence of two polarization processes in different frequency ranges. The presence of kinetic and as well as diffusion processes in polarization of the samples with x = 10 and 15 at% of Cu strongly affects the unusually high values of the real part of dielectric permittivity in low- and medium-frequency range.
关键词： AC impedance spectroscopy,electrical properties,thermal properties,Cu modification,DSC,As–Se glasses
更新于2025-09-10 09:29:36
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Think Outside the Band: Design and Miniaturization of Absorptive Filters
摘要： This article reviewed a number of different approaches for creating absorptive filters. Unlike most conventional filters, these do not reflect or trap unwanted signals. Instead, they remove them from the system. This alleviates many of the problems associated with out-of-band reactive terminations impacting broad-band or nonlinear components, such as mixers, amplifiers, and ADCs. Recent developments in so-called reflectionless filters solve many of the issues with more classical approaches for absorptive filtering and are a viable technology in applications such as those for the IoS, where miniaturization is critical.
关键词： microwave engineering,reflectionless filters,absorptive filters,impedance matching
更新于2025-09-10 09:29:36
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Bandstop Frequency-Selective Structures Based on Stepped-Impedance Loop Resonators: Design, Analysis and Measurement
摘要： A new dual-polarized and dual-band second-order bandstop 3-D frequency-selective structure (FSS) is proposed with arbitrary band ratio. Compared with the square loop, the stepped-impedance loop resonator performs at a lower basic resonant frequency and increases the first spurious resonant frequency. Different half-wavelength stepped-impedance loop resonators are analyzed, compared and employed to design single /dual-band 3-D FSSs under TE polarization. A double-sided stepped-impedance loop resonator with via holes is presented for constructing a dual-polarized single-band FSS. By adjusting widths of low characteristic impedance sections, the FSS’s band can be expanded into dual bands. Detailed analysis of the coupling between both identical resonators in series is provided for understanding the relationships between sub-resonators. In addition, the equivalent circuit models are developed to explain the operating principle and analyze parameter effects. The proposed FSS prototype is fabricated and then measured to verify the design methodology. The measured results agree with the simulated data and exhibit a dual-polarized and stable second-order bandstop response under different incident angles up to 30o. The thickness of the structure is 23% of the free-space wavelength at the first center frequency, and the center frequency ratio of both stopbands is only 1.08.
关键词： Stepped-impedance loop resonator,Bandstop,Equivalent circuit model,3-D frequency-selective structure,Coupling
更新于2025-09-10 09:29:36
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BIFEVOX Composites: Manufacture and Characterization
摘要： Design of composites is a way to improve the quality of solid electrolytes. By mechanically mixing and annealing substituted bismuth vanadate with nanosized aluminum, bismuth, and zirconium binary oxides, we obtained heterogeneous materials Bi4V1.7Fe0.3O11 – δ/xAl2O3, Bi4V1.7Fe0.3O11 – δ/xBi2O3, and Bi4V1.7Fe0.3O11 – δ/xYSZ. The investigation tools were X-ray powder diffraction and electron microscopy with energy-dispersive microanalysis. The composition of materials was studied, the non-interaction of components was elucidated in the aluminum oxide and zirconium oxide composite series, and a nonuniform distribution of nanopowder particles across the surfaces and cleaves of sinters was discovered. The bismuth atoms from bismuth oxide were shown to be capable of incorporating into the Bi4Fe0.3V1.7O11 – δ structure. The charge transport characteristics of the materials were studied by impedance spectroscopy. No changes were observed in logσ–103/T trends in composites with various binary oxides and various oxide contents. An increase in binary oxide concentration was shown to give rise to an insignificant decay in electrical conductivity.
关键词： composite materials,bismuth vanadates,impedance spectroscopy,bismuth oxide,oxygen-ion conductors
更新于2025-09-10 09:29:36
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Conductive and photoactive nature of conjugated polymer based on thiophene functionalized thiazole or benzothiadiazole
摘要： New poly (thiophene vinyl thiazole) (PTVT) and poly (thiophene vinyl benzothiadiazole) (PTVBT) was synthesized by Wittig condensation route. The absorption maximum of PTVT and PTVBT appeared at 376 and 410 nm in a solution state, and it was red-shifted to 417 and 510 nm in a thin film state. The optical band gaps were 1.7 and 1.5 eV calculated from thin film absorption edges of the polymer. The photoluminescence spectra of PTVT and PTVBT have an emission peak at 457 nm with bluish green and 487 nm with greenish-yellow fluorescence in THF solution. Both polymers showed a short fluorescence decay time (τ1) of 2.31 and 0.73 ns respectively. Furthermore, the aggregation-caused quenching (ACQ) phenomenon observed in both polymers in decreased fluorescence intensity with different water fractions. The lower electrochemical band gaps were achieved for both polymers (1.4, and 1.3 eV) from cyclic voltammetry. Both polymers have a granular shaped morphology with good surface roughness was observed using AFM. High thermal stability was observed with 8% weight loss at 400 °C for PTVT and 6% weight loss at 460°C for PTVBT. The highest electrical conductivity was observed from electrochemical impedance measurement which was 7.68·10–6 Ω–1·cm–1 for PTVBT.
关键词： poly(p-phenylenevinylene),thermal properties,band gap,photoluminescence,impedance
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu, China (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - A Compact Broadband Filter Using Triple-Mode Stepped-Impedance Stub-Loaded Resonator
摘要： In this paper, a compact broadband bandpass filter (BPF) using triple-mode stepped-impedance stub-loaded resonator (TMSISLR) is proposed. The TMSISLR is composed of an impedance-transforming unit and two asymmetrical open-ended stepped-impedance stubs (SIS) at the center. By simply adjusting the impedances of the SIS, the resonant frequencies of the TMSISLR can be flexibly changed. The interdigital coupled-lines are adopted to feed the proposed TMSISLR. This BPF can realize wide bandwidth, low insertion loss, high selectivity, and deep stopband rejection simultaneously. Finally, the proposed BPF is simulated, fabricated, and measured. The measured results show that the impedance bandwidth under -16.7 dB is 86% from 1.89 to 4.75 GHz, while the insertion loss is smaller than 1.47 dB. The measured insertion loss is larger than 30 dB at both low- and upper-stopband (from 0 to 1.27 GHz and 6.03 to 7.66 GHz). The measured results are in good agreement with the simulated counterpart.
关键词： stepped-impedance stubs,broadband,triple-mode resonator,filter
更新于2025-09-10 09:29:36
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Surface Plasmon Resonance Sensing of Biological Warfare Agent Botulinum Neurotoxin A
摘要： A label free real time method was developed for the detection as well as quantification of botulinum neurotoxin A (BoNT/A) using surface plasmon resonance (SPR). In the present work, antibody against rBoNT/A-HCC fragment and synaptic vesicles (SV) were immobilized on carboxymethyldextran modified gold chip. The immobilization of BoNT/A antibody and interaction of BoNT/A with immobilized antibody were in-situ characterized by SPR and electrochemical impedance spectroscopy. A sample solution containing BoNT/A antigen in the concentration ranging from 0.225 fM to 4.5 fM and 0.045 fM to 5.62 fM was interacted with immobilized antibody and immobilized SV, respectively. By using kinetic evaluation software, KD (equilibrium constant) and Bmax (maximum binding capacity of analyte) values were calculated and found to be 0.53 fM and 38.23 mo for immobilized antibody and 0.22 fM and 116.0 mo for immobilized SV, respectively. Moreover, thermodynamic parameters such as change in Gibb’s free energy (?G), change in enthalpy (?H) and change in entropy (?S) were determined and the values revealed that the interaction between BoNT/A antigen and BoNT/A antibody as spontaneous, endothermic and entropy driven one. In order to optimize the detection method, temperature and pH variation studies were also performed.
关键词： SPR,Impedance,Biological warfare agent,BoNT/A
更新于2025-09-10 09:29:36