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In this paper, we report on the electrical impedance measurement of human endothelial cellular networks and show the existence of emergent power law behavior in its admittance. In particular, we find that the admittance scales with the frequency ω as ωα, with the exponent that varies with the degree of the disruption caused by the inflammation in the endothelial cellular network. We demonstrate that the power law of the measured electrical admittance can be understood by a simple percolation model of a large R–C (resistor–capacitor) network, which allows us to relate quantitatively and the intensity of inflammation. Our results suggest that the electrical properties of heterogeneous biomaterials, like living tissues, behave as a complex microstructural network. [ABSTRACT FROM AUTHOR]

Early-stage nonalcoholic fatty liver disease (NAFLD) is a silent condition, with most cases going undiagnosed, potentially progressing to liver cirrhosis and cancer. A non-invasive and cost-effective detection method for early-stage NAFLD detection is a public health priority but challenging. In this study, an adhesive, soft on-skin sensor with low electrode-skin contact impedance for early-stage NAFLD detection is fabricated. A method is developed to synthesize platinum nanoparticles and reduced graphene quantum dots onto the on-skin sensor to reduce electrode-skin contact impedance by increasing double-layer capacitance, thereby enhancing detection accuracy. Furthermore, an attention-based deep learning algorithm is introduced to differentiate impedance signals associated with early-stage NAFLD in high-fat-diet-fed low-density lipoprotein receptor knockout (Ldlr-/-) mice compared to healthy controls. The integration of an adhesive, soft on-skin sensor with low electrode-skin contact impedance and the attention-based deep learning algorithm significantly enhances the detection accuracy for early-stage NAFLD, achieving a rate above 97.5% with an area under the receiver operating characteristic curve (AUC) of 1.0. The findings present a non-invasive approach for early-stage NAFLD detection and display a strategy for improved early detection through on-skin electronics and deep learning.

Nafion is a sulfonated tetrafluoroethylene based fluoropolymer that has been widely used as a membrane material for various applications, such as fuel cells, batteries, and sensors. Nafion has some unique properties that make it suitable for biosensing, such as high ionic conductivity, biocompatibility, chemical stability, and perm selectivity. Nafion can also act as an immobilization matrix for enzymes, antibodies, DNA molecules, and other biomolecules, enhancing their stability and activity on the electrode surface. In this review, we summarize the recent advances and applications of nafion based biosensors for the detection of various analytes, such as glucose, lactate, hydrogen peroxide, DNA, urea, and dopamin. We also discuss the incorporation of nanoparticles into nafion based biosensors, as they can form synergistic interactions that can improve the biocompatibility, stability, selectivity, and sensitivity of the biosensor. We highlight the different transduction methods employed by nafion based biosensors, such as electrochemical, electro chemiluminescence, or electrical impedance. Finally, we outline the challenges and opportunities for future research on nafion based biosensors. [ABSTRACT FROM AUTHOR]

This study explores the influence of Co2+ and Cr3+ doping on the microstructure and electrical properties of Ba-hexagonal ferrite synthesized using the sol-gel method. X-ray diffraction (XRD) confirmed the formation of the anticipated hexagonal M-type crystal structure. Field emission scanning electron microscopy (FESEM) revealed the evolution of grain morphology with increasing doping levels, showcasing the formation of needle-like grains. Electrical characterization using an impedance analyzer investigated dielectric, impedance, electric modulus, and conductivity properties at room temperature. The analysis of the dielectric spectra indicated a decrease in dielectric constant and an increase in loss tangent with increasing dopant concentration. The electric modulus spectra provided evidence for non-Debye relaxation behavior, further supported by observations of relaxation processes at varying frequencies in the conductivity spectra. Additionally, an increase in doping led to a decrease in both relaxation time and AC conductivity. Electrochemical impedance spectroscopy (EIS) measurements yielded complex impedance curves. These curves exhibited good agreement with the values obtained through software-based simulations of grain and grain boundary characteristics. Furthermore, the distribution of grains and grain boundaries observed in FESEM micrographs aligned with the patterns predicted by the EIS software. [ABSTRACT FROM AUTHOR]

Doping silicon wafers without using highly toxic or corrosive chemical substances has become a critical issue for semiconductor device manufacturing. In this work, ultra‐thin films of hydroxyapatite (Ca5(PO4)3OH) are prepared by tethering by aggregation and growth (T‐BAG), and further processed by spike annealing. Via in situ infrared (IR), the decomposition of hydroxyapatite and intermixing with the native silicon oxide is observed already at temperatures as low as 200 °C. Phosphate transport through the native silicon oxide is driven by a phase transformation into a more stable thermal oxide. At 700 °C, diffusion of phosphorus into the sub‐surface region of oxide‐free silicon is observed. In situ IR combined with electrical impedance spectroscopy (EIS), time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS), and X‐ray photoelectron spectroscopy (XPS) measurements allows to conclude that the phosphorus is: i) transported through the silicon oxide barrier, ii)) diffused inside the oxide‐free silicon, and iii) finally modified the electrical activity of the silicon wafer. To further explain the experimental findings, density‐functional theory (DFT) is used to demonstrate the extent of the effect of phosphorus doping on the electronic nature of silicon surfaces, showing that even small amounts of doping can have a measurable effect on the electrical performance of semiconductor wafers. [ABSTRACT FROM AUTHOR]

The penetration of solar energy into centralized electric grids has increased significantly during the last decade. Although the electricity from photovoltaics (PVs) can deliver clean and cost-effective energy, the intermittent nature of the sunlight can lead to challenges with electric grid stability. Smart inverter-based resources (IBRs) can be used to mitigate the impact of such high penetration of renewable energy, as well as to support grid reliability by improving the voltage and frequency stability with embedded control functions such as Volt-VAR, Volt–Watt, and Frequency–Watt. In this work, the results of an extensive experimental study of possible interactions between the unstable grid and two residential-scale inverters from different brands under different active and reactive power controls are presented. Two impedance circuits were installed between Power Hardware-in-the-loop (P-HIL) equipment to represent the impedance in an electric distribution line. Grid voltage and frequency were varied between extreme values outside of the normal range to test the response of the two inverters operating under different controls. The key findings highlighted that different inverters that have met the same requirements of IEEE 1547-2018 responded to grid instabilities differently. Therefore, commissioning tests to ensure inverter performance are crucial. In addition to the grid control, the residential PV installed capacity and physical distances between PV homes and the substation, which impacted the distribution wiring impedance which we characterized by the ratio of the reactive to real impedance (X/R), should be considered when assigning the grid-supporting control setpoints to smart inverters. A higher X/R of 3.5 allowed for more effective control to alleviate both voltage and frequency stability. The elimination of deadband in an aggressive Volt-VAR control also enhanced the ability to control voltage during extreme fluctuation. The analysis of sudden spikes in the grid responses to a large frequency drop showed that a shallow slope of 1.5 kW/Hz in the droop control resulted in a >65% lower sudden reactive power overshoot amplitude than a steeper slope of 2.8 kW/Hz. [ABSTRACT FROM AUTHOR]

Carbon-based electrodes have recently been most widely used in P-MFC due to their desirable properties such as biocompatibility, chemical stability, affordable price, corrosion resistance, and ease of regeneration. In general, carbon-based electrodes, particularly graphite, are produced using a complex process based on petroleum derivatives at very high temperatures. This study aims to produce electrodes from bio-pitch and charcoal powder as an alternative to graphite electrodes. The carbons used to manufacture the electrodes were obtained by the carbonisation of Robinia pseudoacacia and Azadirachta indica wood. These carbons were pulverised, sieved to 50 µm, and used as the raw materials for electrode manufacturing. The binder used was bio-pitch derived from coconut shells as the raw materials. The density and coking value of the bio-pitch revealed its potential as a good alternative to coal-tar pitch for electrode manufacturing. The electrodes were made by mixing 66.50% of each carbon powder and 33.50% of bio-pitch. The resulting mixture was moulded into a cylindrical tube 8 mm in diameter and 80 mm in length. The raw electrodes obtained were subjected to heat treatment at 800 °C or 1000 °C in an inert medium. The electrical resistivity obtained by the four-point method showed that N1000 has an electrical resistivity at least five times lower than all the electrodes developed and two times higher than that of G. Fourier-transform infrared spectroscopy (FTIR) was used to determine the compositional features of the samples and their surface roughness was characterised by atomic force microscopy (AFM). Charge transfer was determined by electrical impedance spectroscopy (EIS). The FTIR of the electrodes showed that N1000 has a spectrum that is more similar to that of G compared to the others. The EIS showed the high ionic mobility of the ions and therefore that N1000 has a higher charge transfer compared to G and the others. AFM analysis revealed that N1000 had the highest surface roughness in this study. [ABSTRACT FROM AUTHOR]

This article discusses the use of SCINSEV measures in cochlear implant surgery to detect and correct electrode extrusion. The study presents three cases where SCINSEV was used to identify extrusion and make immediate surgical corrections, eliminating the need for revision surgery. The authors suggest that SCINSEV, along with other measures, can improve the efficiency and outcomes of cochlear implant surgery by reducing the reliance on x-rays and the need for revision surgery. The article provides detailed information on the methodology and results of the study, highlighting the potential of SCINSEV as an important tool in intraoperative decision-making and correction. [Extracted from the article]

In this work, we study the effect of Ni-doping on the structural and impedance spectroscopy properties of the polycrystalline YCrO 3 ceramic sample. The structural analysis shows all the samples crystallize in an orthorhombic structure with the Pnma space group. The depressed and asymmetric semicircle of complex impedance spectra indicates that the relaxation of charge carriers is of non-Debye type, where the thermally activated charge carriers control it. The temperature dependence of relaxation time and electrical conductivity exhibit an anomaly in the vicinity of diffuse-like relaxor transition temperature (T C ∼ 460 K). The analysis of conductivity data shows hopping-type charge conduction. The analysis further indicates that while the dc conductivity increases continuously, the activation energy shows a non-monotonous variation with Ni concentration. [ABSTRACT FROM AUTHOR]

Background: Overweight and obesity have increased significantly worldwide, placing major economic problems on health systems. This study aims to determine socio-economic characteristics, dietary practices, physical activity levels, nutrition status, predictors of overweight and obesity, and their relationships among adolescents. Methods: The study adopted a crosssectional analytical study design. 401 adolescents were randomly selected from five secondary day schools using a proportionate-to-size sampling method. Results: Based on the findings, one third (36.3%) of the adolescents were between ages 17-18, with more girls (55.9%) than boys. The number of meals consumed per day among adolescents was 3.34±1.24. Individual dietary diversity score among adolescents was 4.21±1.61. Based on Body Mass Index (BMI), the prevalence of overweight and obesity among boys was 5.2% and 1.8%, respectively, and for girls, it was 7.3% and 3.6%, respectively. Using bioelectrical impedance analysis, the prevalence rates for males were 8.8% and 4.1%, respectively, while for females the rates were 10.1% and 5.1%. Regression analysis revealed that the most significant predictors were energy intake and physical activity, with P=0.05 based on BMI and bioelectrical impedance analysis. Conclusion: There is a significant relationship between nutritional status and energy intake, the number of meals, dietary diversity score, and physical activity. Physical activity and dietary practices were the most important predictors of overweight and obesity among adolescents. The study recommends nutrition education and public health interventions in schools' curricula. [ABSTRACT FROM AUTHOR]

Achieving non-destructive detection of aflatoxin in peanuts can prevent the processing of aflatoxin-contaminated peanuts into food products. A potential non-destructive electrical impedance spectroscopy method for aflatoxin B1 (AFB1) in peanuts is proposed. To research the relationship between electrical parameters and aflatoxins, this study analyzed the effects of improper storage duration on the content of aflatoxins and conducted experiments using impedance spectroscopy and NMR with different content of AFB1. Results showed that the aflatoxin content was proportional to the number of days of improper storage. The impedance Z could as an indicator for characterizing AFB1. The parameters of electrical impedance spectrum under multi-frequency (1000 Hz and 4 MHz) were better than those under the single frequency (1000 Hz or 4 MHz), and the combination of Z and θ showed the best correlation (R2 = 0.998). The detection mechanism was accurate under improper storage conditions, and aflatoxin production was accompanied by moldy kernel, leading to changes in endosperm structure and impedance. Our study informs the development of non-destructive detection devices for aflatoxins in peanuts. [ABSTRACT FROM AUTHOR]

In this work, ion-doped hydroxyapatite materials were synthesized using the sol-gel technique. XRD analysis confirmed the purity of the products, with no secondary peaks observed. Doping with manganese, lithium, potassium, and zinc ions resulted in a crystalline size of 47–48 nm. Fourier transform infrared spectroscopy validated the structural bands, while scanning electron microscopy and energy-dispersive X-ray spectroscopy revealed nano-rod-like particles with sizes ranging from 30 to 80 nm in length and 13 to 40 nm in width. Impedance spectroscopy and dielectric relaxation studies showed electrical behaviour following the Maxwell-Wagner mechanism and non-Debye type relaxation. The materials exhibited strong antibacterial properties, making them promising for medical implant applications. [ABSTRACT FROM AUTHOR]

AC‐operating electrochemiluminescent devices (ECLDs) have recently shown a substantial increase in brightness, making them potentially relevant for applications in lighting and displays. To further improve the performance of these liquid‐state light‐emitting devices, it is essential to reliably assess the absolute quantum efficiency of electrochemiluminescence and the electrochemical reactions leading to exciton formation. However, significant non‐faradaic currents occurring under the AC operation schemes make it challenging to quantify the number of charges involved in the electrochemical reactions. Here, faradaic and non‐faradaic currents in sandwich‐type ECLDs are analysed by electric impedance spectroscopy and to assess the absolute quantum efficiency of the electrochemiluminescence (ΦECL). An equivalent circuit model enables analysis of the current at different voltage amplitudes and operating frequencies. The analysis reveals that non‐faradaic currents stem primarily from capacitive currents associated with the formation of electric double‐layers near liquid/electrode interfaces. Their contribution to the total current increases at high operating frequencies and low voltages. For ECLDs operating based on an exciplex‐formation and energy transfer pathway, the estimated ΦECL and resulting exciton formation efficiency are 0.53% and 27%, respectively. Reverse redox reactions are identified as a significant loss factor, thus indicating potential avenues for future improvements. [ABSTRACT FROM AUTHOR]

Growing body of evidence suggests that cardiovascular risk factor, asymmetric dimethylarginine (ADMA), can be implicated in the pathogenesis of neurodegenerative and psychiatric disorders. In part, ADMA can affect brain health negatively modulating critical functions of the blood-brain barrier (BBB). The precise mechanisms and consequences of ADMA action on the cerebral vasculature remains unexplored. Here, we evaluated ADMA-induced maladaptation of BBB functions by analyzing real time electrical cell-substrate impedance, paracellular permeability, immune-endothelial interactions, and inflammatory cytokines production by primary human brain microvascular endothelial cells (hBMVEC) treated with ADMA. We found that ADMA disrupted physical barrier function as evident by significant decrease in electrical resistance and increase in paracellular permeability of hBMVEC monolayers. Next, ADMA triggered immune-endothelial interactions since adhesion of primary human monocytes and their extravasation across the endothelialmonolayer both were significantly elevated upon treatment with ADMA. Increased levels of cell adhesion molecules (VCAM-1 and RANTES), VEGF-A and inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-10, IL-4, IL-2, IL-13, IL-12p70) characterize ADMA-induced hBMVEC dysfunction as inflammatory. Overall, our data suggest that ADMA can impair BBB functions disrupting the endothelial barrier and eliciting neuroinflammatory and neuroimmune responses. [ABSTRACT FROM AUTHOR]

Transient receptor potential vanilloid 4 (TRPV4) channels have been associated with numerous pulmonary pathologies, including hypertension, asthma, and acute lung injury. However, their role in the alveolar epithelium remains unclear. We performed impedance-based resistance measurements in primary differentiated alveolar epithelial type I (AT1) cells from wild-type (WT) and TRPV4-deficient (TRPV4−/−) C57/BL6J mice to detect changes in AT1 barrier integrity upon TRPV4 activation. Both pharmacological (GSK1016790A) and a low pH-driven activation of TRPV4 were quantified, and the downstream effects on adherens junctions were assessed through the Western blotting of epithelial cadherin (E-cadherin) protein levels. Importantly, a drop in pH caused a rapid decrease in AT1 barrier resistance and increased the formation of a ~35 kDa E-cadherin C-terminal fragment, with both effects significantly reduced in TRPV4−/− AT1 cells. Similarly, the pharmacological activation of TRPV4 in AT1 cells triggered an immediate transient loss of barrier resistance and the formation of the same E-cadherin fragment, which was again diminished by TRPV4 deficiency. Moreover, TRPV4-mediated E-cadherin cleavage was significantly reduced by GI254023X, an antagonist of a disintegrin and metalloprotease 10 (ADAM10). Our results confirm the role of TRPV4 in regulating alveolar epithelial barrier permeability and provide insight into a novel signaling pathway by which TRPV4-induced Ca2+ influx stimulates metalloprotease-driven ectodomain shedding. [ABSTRACT FROM AUTHOR]

Due to their mechanical robustness and chemical resistance, composite electrospun membranes based on polyvinyl chloride (PVC) are suitable for sensor applications. Aiming to improve the electrical characteristics of these membranes, this work investigated the effects of the addition of carbon nanotubes (CNTs) to PVC electrospun membranes, in terms of morphology and thermal and impedance behavior. Transmission electron microscopy images evidenced that most of the nanotubes were encapsulated within the fibers and oriented along them, while field-emission scanning electron micrographs revealed that the membranes consisted of uniform fibers with an average diameter of 339 ± 31 nm, regardless of the addition of the carbon nanotubes. With respect to the neat resin, the addition of nanotubes caused a significant lowering of the glass transition temperature (up to 20 °C) and a marked change in the second degradation step of PVC. Nyquist plots from electrical impedance spectra showed a charge transfer resistance (RCT) of 38 and 40 MΩ for neat PVC and PVC/CNT 3 wt.% membranes, respectively, indicating that, in the dry state, the encapsulation of CNTs in the fibers and the high porosity of the membranes prevented the formation of a percolation network, increasing the electrical resistance. In the wet state, however, there was a greater change in the impedance behavior, decreasing the resistance RCT to 4.5 and 1.1 MΩ, for neat PVC and PVC/CNT 3 wt.% membranes, respectively. The results of this study, showing a significant variation in impedance behavior between dry and wet membranes, are relevant for the development of various types of sensors based on PVC composites. [ABSTRACT FROM AUTHOR]

One of the ways to turn concrete into smart concrete involves the incorporation of conductive fillers. These fillers should be evenly distributed in the matrix to enable the charge propagation necessary for sensing. To homogenize the mixture, typical surface-active chemical compounds are routinely employed. Unfortunately, their presence often negatively impacts the characteristics of concrete. In this work, we show that conductive multi-walled carbon nanotubes (MWCNTs) can be included in the concrete matrix by using off-the-shelf lignosulfonate-based plasticizers. These plasticizers showed a much-improved capability to disperse MWCNTs compared to other routinely used surfactants. They also prevented a significant deterioration of the consistency of the mixture and inhibited the acceleration of the hydration process by MWCNTs. In concretes with MWCNTs and lignosulfonate-based plasticizers, the mechanical properties were largely preserved, while the nanocomposite became electrically conductive. Consequently, it enabled evaluation of the condition of the material by electrical impedance measurements. [ABSTRACT FROM AUTHOR]

ABSTRACT The accurate emulation of the electrical impedance of biological tissues is crucial for the development and validation of bioimpedance measurement devices and algorithms. This paper describes a digitally controllable impedance emulator capable of reproducing values representative of tissue bioimpedance in user‐specified resistance, reactance, and frequency ranges up to 1 MHz. The presented solution uses a 2R‐1C impedance model to emulate the impedance characteristics of a biological tissue. Specific selection of each element value in this model is achieved using analog multiplexers with low Ron$$ {R}_{on} $$ resistance. A MATLAB algorithm was developed for value estimation using target impedance requirements. An example design to emulate impedance from 1 kHz to 1 MHz with 10 Ω$$ \Omega $$ to 400 Ω$$ \Omega $$ resistance and −45Ω$$ -45\Omega $$ maximum reactance is provided. The nonideal behavior of this design was evaluated and compared against experimentally collected impedance measurements. Deviations of <1% were observed between experimental and theoretical resistances for values >50Ω$$ >50\Omega $$ up to 100 kHz (with approximately 5% deviations up to 1 MHz) and reactance deviations were also <1% up to 10 kHz. High frequency deviations are attributed to the parasitic capacitance in the realization of the design. The experimental results validate the design approach and realization for low frequencies. Overall, the innovation of the proposed approach is the control of both resistance and reactance for emulating electrical impedance representative of biological tissues. [ABSTRACT FROM AUTHOR]

Capacitively Coupled Electrical Impedance Tomography (CCEIT), as a new electrical tomography method, effectively overcomes the drawbacks of traditional electrical resistance tomography that requires direct contact with liquids, so as to achieve non-contact measurement. In order to make full use of the complete electrical impedance information (real and imaginary) obtained by CCEIT and further improve the quality of image reconstruction, an image fusion algorithm based on wavelet transform was proposed. First, the Landweber algorithm is used to image the real part information and the imaginary part information, and the wavelet transform algorithm is used to decompose the two images at multiple scales, in which the low-frequency coefficient is fused by the improved logic filter algorithm based on the adaptive threshold, the high-frequency coefficient is selected based on the absolute value maximum method for fusion, and finally, the fused image is obtained by wavelet reconstruction. Numerical simulations and experiments verify the feasibility of the proposed method, and the results show that the relative error is reduced by up to 17% and the correlation coefficient is increased by up to 10%. [ABSTRACT FROM AUTHOR]

Abdominal hemorrhage is an important clinical disease that can be life-threatening in severe cases. Therefore, timely detection and treatment of abdominal hemorrhage is crucial for the health and safety of patients. Magnetic induction tomography is a non-invasive, nonradioactive, and non-contact electromagnetic imaging technology with potential application value for disease screening and continuous monitoring. In this paper, a simulation model of electrical impedance distribution close to the real human abdominal tissue was constructed, and based on this model, the magnetic induction tomography simulation method of internal bleeding was studied by the finite element numerical method, and the comparison was verified by phantom experiments. The eddy current density distribution inside the abdominal tissue and the magnetic induction phase data at the tissue boundary are solved, and sensitivity analysis of phase differences caused by changes in the radius and position of bleeding volume was conducted, and three sensitivity indicators were proposed. Both the simulation and phantom experiment show that when there are six types of tissues with different conductivity in the abdomen, the radius of bleeding increases from 10 to 30 mm, and the radius phase difference sensitivity index Ar increases approximately linearly monotonically. Its radius transformation sensitivity Kr is 3.0961 × 10−5°/cm. When the position of the bleeding volume changes, the sensitivity index Ax of the x-axis displacement phase difference shows a quasilinear monotonic decrease, and the x-axis displacement sensitivity Kx is −6.3744 × 10−6°/cm. The y-axis displacement phase difference sensitivity Ay index shows a quasilinear relationship and monotonically increases, with a y-axis displacement sensitivity Ky of 5.2870 × 10−4°/cm. The results indicate that the phase difference sensitivity before and after the occurrence of bleeding can be used as a quantitative monitoring indicator to monitor the occurrence and trend of intra-abdominal hemorrhage, laying the foundation for the preliminary screening and continuous monitoring of abdominal hemorrhage diseases using magnetic induction imaging. [ABSTRACT FROM AUTHOR]

Ferroelectric (FE) materials and their advancements have piqued the scientific community's interest greatly since they provide numerous fascinating processes in addition to being used in devices. Among them, we have studied Mn and Sn co-doped PZT and Pb (Zr0.52Ti0.48) O3 as PZT, an extremely intriguing FE. The structure and phase purity of all the samples are determined by x-ray diffraction techniques. All the samples show a very good microstructures and the average grain size is found to be decreased with ion incorporation. The UV-Vis spectra show how doping reduces optical band gaps. Parallel resistance (R)-capacitance (C) circuits have been used to analyze the relationship between microstructure and electrical characteristics. The microscopic processes in various PZT samples with dilute magnetic cations at A-sites, B-sites, and/or both sites at the morphotopic phase boundary are established from the detail impedance, modulus, and ac conductivity of the samples as a function of temperature (300 –500 °C) and over a range of frequency (100 Hz to 1 MHz). Additionally, the framework of the Jump relaxation model and the Jonscher power law are used to study the ac-conductivity data. [ABSTRACT FROM AUTHOR]

Background: The primary objective of this research is to propose an intra-operative tumor detection probe calibrated on human models of gastrointestinal (G.I.) cancers, enabling real-time scanning of dissected masses. Methods: Electrical Gastrointestinal Cancer Detection (EGCD) measures impedimetric characteristics of G.I. masses using a handpiece probe and a needle-based head probe. Impedance Phase Slope (IPS) and impedance magnitude (Z1kHz) are extracted as the classification parameters. EGCD was tested on palpable G.I. masses and compared to histopathology results. Results: Calibration was carried out on 120 GI mass samples. Considering pathological results as the gold standard, most cancer masses showed Z1kHz between 100 Ω and 2500 Ω while their IPS was between −15 and −1. The EGCD total sensitivity and specificity of this categorization in G.I. cancer patients with palpable tumors were 86.4% and 74.4%, respectively (p-value < 0.01). Conclusion: EGCD scoring can be used for 3D scanning of palpable tumors in G.I. tumors during surgery, which can help clarify the tumors' pathological response to neoadjuvant chemotherapy or the nature of intra-operative newly found G.I. tumors for the surgeon to manage their surgical procedure better. [ABSTRACT FROM AUTHOR]

By coating the electrodes of a cochlear implant (CI) electrode array with a powdered form of molecularly imprinted polymer (MIP), a straightforward process to functionalize existing electrodes to selectively detect histamine is demonstrated. Detection is based on non‐Faradaic impedance spectroscopy, omitting the need for a reference electrode or redox mediators, and fitting to a 5‐element equivalent electronic circuit. Proof‐of‐concept measurements on three functionalized cochlear implants in three human cadaveric cochleae indicate a level of detection of 200 nM of histamine in albumin‐based artificial perilymph following a sigmoid dose‐response trend up to 10 mM. This sensitivity enables quantized and localized analysis of histamine‐mediated inflammation immediately following the CI operation. The selectivity and adaptability of MIPs opens possibilities to detect a wide spectrum of inflammation markers inside the human cochlea and could be used for fast mid‐ or postoperative intervention to improve the medical implant's outcome. [ABSTRACT FROM AUTHOR]

Spaceflight results in marked muscle atrophy and a corresponding loss in muscle strength. Methods to evaluate spaceflight-induced changes to muscle size and strength are difficult to achieve within the tight confines of spacecrafts. Therefore, convenient methods to non-invasively monitor muscle that are predictive of actual muscle function are critical for future missions to ensure the health and safety of crew members. Evaluate the ability of non-invasive in vivo electrical impedance myography (EIM) combined with statistical models to predict muscle size and strength in rodent models of micro- and partial gravity. Male and female Fisher rats (N = 120), half gonadectomized, were divided into three different weightbearing (WB) conditions of 40 animals each, including 0%WB (0 % of weight-bearing, simulated microgravity), 40%WB (40 % of weight-bearing, simulated Martian gravity), and 100%WB (100 % of weight-bearing, full weight-bearing controls). Rats remained in designated interventions for 28 days. Afterward, rats underwent a series of musculoskeletal strength assessments and measurement of EIM. Rats were then euthanized and gastrocnemius tissues collected. Machine-learning (ML) algorithms were applied to full spectrum EIM data to predict various muscle parameters. 40%WB and 0%WB rats had lower grip strength and plantar flexion compared to 100%WB. Correspondingly, 40%WB and 0%WB also had reduced gastrocnemius mass compared to 100%WB. EIM resistance values demonstrated a dose-dependency response, with greater resistance values associated with reduced gravitational load. ML-enhanced EIM yielded strong predictions of muscle plantar flexion force and muscle mass, with root mean squared errors of 18.4 % of 22.0 %, and R2 values of 0.87 an 0.88, respectively. ML-enhanced EIM may be a helpful tool to non-invasively monitor muscle changes predictive of muscle force production and mass during exposure to reduced gravity. • Electrical impedance myography (EIM) data can be used to predict muscle mass in rats exposed to reduced loading. • EIM data can be used to predict muscle force in rats exposed to reduced loading. • These data support that EIM may find use as a predictor of muscle function in human spaceflight. [ABSTRACT FROM AUTHOR]

This study describes the nondestructive testing and evaluation of different clay–lime composites by real-time impedance spectroscopy (IS) monitoring of lime hydration and cementation mechanisms. The experimental investigations were carried out on two different clays, white clay (with predominantly kaolinite mineralogy) and brown clay (with predominantly montmorillonite mineralogy), to determine the influence of clay mineralogy on the fate of lime stabilization processes in different soils. Additionally, the effects of key influencing parameters such as lime content, curing period, and curing temperature were assessed. The time-dependent electrical impedance behavior of different clay–lime systems was determined in terms of bulk resistance and interfacial capacitance, obtained by equivalent circuit modeling of the impedance spectra. The variations in the electrical impedance properties showed a strong correlation with unconfined compressive strength (UCS) of different clay–lime composites. Further, the microstructural improvement of various clay–lime composites was determined with the aid of scanning electron microscopy, mercury intrusion porosimetry, and thermogravimetric analysis to get an auxiliary interpretation of the electrical impedance spectroscopy (EIS) results. The time-dependent variations of the soil impedance evidently manifested the continuous chemical and morphological evolution of the different clay–lime systems during the curing process at different thermal conditions by the formation and deposition of cementitious calcium-silicate-hydrates (C-S-H) and calcium-aluminate-silicate-hydrates (C-A-S-H) compounds. Overall, the nondestructive impedance spectroscopy technique has been proven effective in describing the microstructural changes and related mechanical improvement of lime-treated soils. Although the use of this technique seems to be inefficient for a field quality control assessment, the analysis of the electrical parameters calculated from the impedance spectra measured gives a comprehensive idea of the evolution in the chemically stabilized soil material. [ABSTRACT FROM AUTHOR]

Insects are a major part of the planet's ecosystem and their vital role as pollinators for agriculture is undisputed. Alongside factors as climate change or loss of habitats, rising use of pesticides emerges as a key threat to insect populations. For fighting this man‐made problem, development of an easy, fast, sensitive, and non‐invasive biosensor for determining pesticide toxicity may help to ban harmful substances and formulations. Here, a biosensor based on Sf21 (Spodoptera frugiperda) insect cells as sensors and electric cell‐substrate impedance sensing (ECIS) as physical transducer is described. Sf21 cell suspensions and well‐defined pesticide solutions were mixed immediately before seeding on planar gold‐film electrodes. The capacitance at 20 kHz was recorded as a function of time as a measurand for cell adhesion providing dose–response profiles of pesticide impact. For future in‐field applications, decoupling of the cell culture routines from the actual cytotoxicity assay is mandatory. Thus, suspensions of Sf21 cells were cryopreserved at –80°C in the wells of multielectrode arrays and thawed anytime for conducting the assays. Five pesticides were tested for their concentration‐dependent cytotoxicity expressed as EC50 values by ECIS and validated using the well‐established WST‐1 cell viability assay. Results were found to be in good agreement. Our studies revealed cytotoxic effects of some pesticides sold for home usage far below the recommended concentration and were found to be more toxic than formulations sold for agricultural industry only. [ABSTRACT FROM AUTHOR]

The noninvasive and label‐free electrical characterization of single cells is increasingly gaining interest over the last years. Besides cancer cells, oocytes are in the focus of those investigations. The study of oocytes is relevant for two areas: on the one hand, the quality of mammalian oocytes is important in artificial reproduction technology for a high fertilization yield. On the other hand, amphibian oocytes are well established to be used as host cells for the characterization of ion‐channel kinetics for drug screening. For both areas, easy‐to‐perform and reliable characterization techniques are needed. This mini‐review summarizes important developments of characterizing oocytes with microfluidic systems in combination with observer‐independent noninvasive electrical sensing. Such miniaturized microfluidic systems can be improved to facilitate multiple oocyte characterizations simultaneously for higher throughput screening. [ABSTRACT FROM AUTHOR]

By using broadband dielectric spectroscopy over a wide frequency and temperature range, the effect of the chain extender and cross‐linkers on molecular dynamics of polyurethanes based on piperazine as a heterocyclic compound was assessed. Three relaxations attributed to local motions of polar side groups and small segments of the polyurethane chain (β, γ‐mode) and glass transition (α‐mode) were detected with the increase in temperature from −120 to 100 °C, along with the conductivity process at high temperatures and low frequencies. Experimental data were examined using the impedance and electric modulus for the conductivity study. Due to the presence of dipole polarization of functional groups in the hard segments, cross‐linked polyurethanes are characterized by higher dielectric constant value (≈11 at 1 kHz and 25 °C) compared to the linear ones (≈6–7 at 1 kHz and 25 °C). High conductivity was achieved for the Tween 20‐cross‐linked polyurethanes. The activation energy for the secondary γ relaxation was in the range of 34–37 kJ mol−1 for all polyurethanes, regardless of the chain extender or cross‐linker used. Piperazine‐based polyurethanes had lower activation energies for α relaxation and high conductivity compared to cyclohexane‐based polyurethanes. This indicates that α relaxation is more vulnerable to structural alterations. [ABSTRACT FROM AUTHOR]

Prostate cancer (PCa) remains a significant health threat, with chemoresistance and recurrence posing major challenges despite advances in treatment. The epithelial to mesenchymal transition (EMT), a biochemical process where cells lose epithelial features and gain mesenchymal traits, is linked to chemoresistance and metastasis. Electrical impedance spectroscopy (EIS), a novel label-free electrokinetic technique, offers promise in detecting cell phenotype changes. In this study, we employed EIS to detect EMT in prostate cancer cells (PCCs). PC3, DU145, and LNCaP cells were treated with EMT induction media for five days. EIS characterization revealed unique impedance spectra correlating with metastatic potential, distinguishing DU145 EMT+ and EMT− cells, and LNCaP EMT+ and EMT− cells (in combination with dielectrophoresis), with comparisons made to epithelial and mesenchymal controls. These changes were supported by shifts in electrical signatures, morphologies, and protein expression, including the downregulation of E-cadherin and upregulation of vimentin. No phenotype change was observed in PC3 cells, which maintained a mesenchymal phenotype. EMT+ cells were also distinguishable from mixtures of EMT+ and EMT− cells. This study demonstrates key advancements: the application of EIS and dielectrophoresis for label-free EMT detection in PCCs, characterization of cell electrical signatures after EMT, and EIS sensitivity to EMT transitions. Detecting EMT in PCa is important to the development of more effective treatments and overcoming the challenges of chemoresistance. [ABSTRACT FROM AUTHOR]

This study investigates the critical electric field thresholds required for phase transitions in the blue phases of liquid crystals (BPs) confined within vertical field switching cells. BPs are attractive for electro-optical applications due to their polarization-independent response and fast switching times; however; challenges remain regarding their limited temperature stability and previously reported high operational voltages. We employ a combined approach of polarized optical microscopy and electrical impedance analysis to identify the electric field thresholds triggering BP transitions to focal conic domains in cells with and without planar polyimide alignment layers. We show that surface alignment layers stabilize the blue phases and allow for higher applied electric fields before transitioning into the focal conic state. This suggests the possibility of a wider operational voltage range in thinner cells with alignment layers. These findings significantly improve our understanding of BPs, addressing key challenges and paving the way for their integration into advanced photonic devices, based on the CMOS technology. [ABSTRACT FROM AUTHOR]

Patients with compromised respiratory function frequently require mechanical ventilation to survive. Unfortunately, non-uniform ventilation of injured lungs generates complex mechanical forces that lead to ventilator induced lung injury (VILI). Although investigators have developed lung-on-a-chip systems to simulate normal respiration, modeling the complex mechanics of VILI as well as the subsequent recovery phase is a challenge. Here we present a novel humanized in vitro ventilator-on-a-chip (VOC) model of the lung microenvironment that simulates the different types of injurious forces generated in the lung during mechanical ventilation. We used transepithelial/endothelial electrical impedance measurements to investigate how individual and simultaneous application of mechanical forces alters real-time changes in barrier integrity during and after injury. We find that compressive stress (i.e. barotrauma) does not significantly alter barrier integrity while over-distention (20% cyclic radial strain, volutrauma) results in decreased barrier integrity that quickly recovers upon removal of mechanical stress. Conversely, surface tension forces generated during airway reopening (atelectrauma), result in a rapid loss of barrier integrity with a delayed recovery relative to volutrauma. Simultaneous application of cyclic stretching (volutrauma) and airway reopening (atelectrauma), indicates that the surface tension forces associated with reopening fluid-occluded lung regions are the primary driver of barrier disruption. Thus, our novel VOC system can monitor the effects of different types of injurious forces on barrier disruption and recovery in real-time and can be used to interogate the biomechanical mechanisms of VILI. [ABSTRACT FROM AUTHOR]

In the rapidly evolving field of human-machine interfaces (HMIs), high-resolution wearable electronic skin (e-skin) is essential for user interaction. However, traditional array-structured tactile interfaces require increased number of interconnects, while soft material-based computational methods have limited functionalities. Here, we introduce a thin and soft e-skin for tactile interfaces, offering high mapping capabilities through electrical impedance tomography (EIT). We employed an organic/inorganic hybrid structure with simple, cost-effective fabrication processes, ensuring flexibility and stability. The conductive and stretchable sensing domain includes a micropatterned multiwall carbon nanotube and elastomer composite. The skin-like tactile interface effectively detects pressure-induced conductivity changes, offering superior spatiotemporal resolution with fewer interconnects (pixel/interconnects >57). This EIT-based tactile interface discerns external pressures to a submillimeter degree and vertical deformations of a few hundred micrometers. It sustains stable functions under external damage or environmental changes, confirming its suitability for persistent wearable use. We demonstrate practical applications in real-time HMIs: handwriting recognition and drone control. [ABSTRACT FROM AUTHOR]

TTFields is a novel FDA-approved technology utilized for treating glioblastoma multiforme (GBM) within the brain. Presently, the effectiveness of therapy is evaluated through MRI imaging at random two-month intervals. Electrical impedance is an important and effective parameter for reflecting changes in tissue properties. In TTFields treatment for brain tumors, electrodes attached to the scalp deliver electric field energy to the tumor region. We hypothesize that these electrodes can also serve as sensors to detect impedance changes caused by tumor alterations in real time, thus continuously assessing the effectiveness of the treatment. In this work, we propose and scrutinize this hypothesis by conducting an in silico study to confirm the potential feasibility of the proposed concept. Our results indicate that the impedance amplitude change measured between opposing TTFields electrode arrays utilizing voltage and frequency of 50 V and 200 kHz (typical TTFields treatment parameters), has enough resolution (> 1mm) and Signal-to-Noise Ratio (> 40 dB) to evaluate tumor size change in the head. The impedance detection technique may be a significant augmentation to TTFields cancer treatment, enabling the continuous evaluation of safety and efficacy throughout the procedure. [ABSTRACT FROM AUTHOR]

We perform dielectric and impedance spectrums on the compressively-strained ceramics of multiferroic bismuth ferrite. The subsurface-nanolayer quasipolarons manifest the step-like characteristic of pressure-dependent transient frequency and, furthermore, pressure-dependency fails in the transformation between complex permittivity and electrical impedance, which is well-known in classic dielectric physics, as well as the bulk dipole chain at the end of the dissipation peak. [ABSTRACT FROM AUTHOR]

Flexible electronic skin (e-skin) can enable robots to have sensory forms similar to human skin, enhancing their ability to obtain more information from touch. The non-invasive nature of electrical impedance tomography (EIT) technology allows electrodes to be arranged only at the edges of the skin, ensuring the stretchability and elasticity of the skin's interior. However, the image quality reconstructed by EIT technology has deteriorated in multi-touch identification, where it is challenging to clearly reflect the number of touchpoints and accurately size the touch areas. This paper proposed an EIT-based flexible tactile sensor that employs self-made hydrogel material as the primary sensing medium. The sensor's structure, fabrication process, and tactile imaging principle were elaborated. To improve the quality of image reconstruction, the fast iterative shrinkage-thresholding algorithm (FISTA) was embedded into the EIDORS toolkit. The performances of the e-skin in aspects of assessing the touching area, quantitative force sensing and multi-touch identification were examined. Results showed that the mean intersection over union (MIoU) of the reconstructed images was improved up to 0.84, and the tactile position can be accurately imaged in the case of the number of the touchpoints up to seven (larger than two to four touchpoints in existing studies), proving that the combination of the proposed sensor and imaging algorithm has high sensitivity and accuracy in multi-touch tactile sensing. The presented e-skin shows potential promise for the application in complex human–robot interaction (HRI) environments, such as prosthetics and wearable devices. [ABSTRACT FROM AUTHOR]

With the rapid development of broadband transducers, there is an increasing demand for enhanced electromechanical properties in lead-free piezoelectric ceramics. In this study, the strategies to enhance the electrical properties of ceramics were explored by doping BaZrO 3 into 0.96(K 0.48 Na 0.52)Nb 0.96 Sb 0.04 O 3 -0.04(Bi 0.5 Ag 0.5)ZrO 3 ceramics, inducing lattice distortion (c / a) and regulating the phase structure. The ceramics doped with 1.5 mol% BaZrO 3 demonstrate excellent electrical performance, with a piezoelectric coefficient (d 33) of 545 pC/N, a relative dielectric constant (ε r) of 4126, and an electromechanical coupling factor (k p) of 54.1 %. The reduced c / a ratio and rhombohedral-orthorhombic-tetragonal phase structure reduce the polarization energy barrier and promote the ordered arrangement of ferroelectric dipoles, thereby enhancing the comprehensive performance of the ceramics. Lastly, the electrical impedance of ceramics is studied in detail and reveals the main conduction mechanism in the microscopic region. This research provides new insights into optimizing the electrical properties of ceramics through microstructural manipulation and demonstrates the potential application of KNN-based ceramics in high performance piezoelectric transducers. [ABSTRACT FROM AUTHOR]

Amyotrophic lateral sclerosis (ALS), a devastating neurodegenerative disease, is characterized by progressive motor neuron degeneration, leading to widespread weakness and respiratory failure. While a variety of mechanisms have been proposed as causes of this disease, a full understanding remains elusive. Electrophysiological alterations, including increased motor axon excitability, likely play an important role in disease progression. There remains a critical need for non-animal disease models that can integrate electrophysiological tools to better understand underlying mechanisms, track disease progression, and evaluate potential therapeutic interventions. This review explores the integration of electrophysiological technologies with ALS disease models. It covers cellular and clinical electrophysiological tools and their applications in ALS research. Additionally, we examine conventional animal models and highlight advancements in humanized models and 3D organoid technologies. By bridging the gap between these models, we aim to enhance our understanding of ALS pathogenesis and facilitate the development of new therapeutic strategies. [ABSTRACT FROM AUTHOR]

Compared to animal cells, phenotypic characterization of single plant cells on microfluidic platforms is still rare. In this work, we collated population statistics on the morphological, biochemical, physical and electrical properties of Arabidopsis protoplasts under different external and internal conditions, using progressively improved microfluidic platforms. First, we analyzed the different effects of three phytohormones (auxin, cytokinin and gibberellin) on the primary cell wall (PCW) regeneration process using a microfluidic flow cytometry platform equipped with a single-channel fluorescence sensor. Second, we correlated the intracellular reactive oxygen species (ROS) level induced by heavy metal stress with the concurrent PCW regeneration process by using a dual-channel fluorescence sensor. Third, by integrating contraction channels, we were able to effectively discriminate variations in cell size while monitoring the intensity of intracellular ROS signaling. Fourth, by combining an electrical impedance electrode with the contraction channel, we analyzed the differences in electrical and mechanical properties of wild-type and mutant plant cells before and after primary cell wall regeneration. Overall, our work demonstrates the feasibility and sensitivity of microfluidic flow cytometry in high-throughput phenotyping of plant cells and provides a reference for assessing metabolic and physiological indicators of individual plant cells in multiple dimensions. [ABSTRACT FROM AUTHOR]

Lithium Aluminosilicate glass-ceramics with striae (LAS-WS) and without striae (LAS-WoS) were processed using melt casting technique. LAS-WS and LAS-WoS samples were characterized and found stress birefringence >10 nm/cm and <10 nm/cm, respectively. LAS-WS and LAS-WoS samples were subjected to structural, microstructural, high temperature dielectric and electrical characterization. The presence of striation did not significantly affected the formation of β-spondumene structure during crystallization heat treatment. TEM image confirms the formation of nanocrystals in the glass matrix of lithium aluminosilicate glass-ceramics. The homogeneous distribution of LAS nanocrystals of average size of 3–6 nm is evident from TEM results. Stress birefringence distribution in lithium aluminosilicate glass-ceramic clearly shows the striae formation. Shadowgraphy images confirmed the striae free and striae containing regions in the glass-ceramic. The effect of striae on dielectric properties and AC conductivity was analysed using impedance spectroscopy and it was found that the value of the relative permittivity decreased from 415 (1.2 Hz) to 9.76 (1.2 MHz) for LAS-WoS and from 401 (1.2 Hz) to 10.3 (1.2 MHz) for LAS-WS, respectively. It was found that striae in LAS glass-ceramics influence the electrical impedance and AC conductivity relaxation process rather than relative permittivity. The effect of striae on crystallization and morphology are presented. Both the samples have shown crystallinity of more than 75 %. The electrical conductivity of σ = 2.0 × 10−3 S/cm for LAS-WoS and 2.7 × 10−3 S/cm for LAS-WS at 300 °C as well as σ = 4.6 × 10−3 S/cm for LAS-WoS and 6.9 × 10−3 S/cm for LAS-WS at 700 °C are found to be in good agreement due to increase in the electrical conductivity with temperature. The ionic conductivity of the material due to Li-ion mobility with respect to temperature and electric field and possible mechanism of AC conductivity are discussed. The results presented indicates the potential application of this material that demands high temperature operation of lithium aluminosilicate glass-ceramics. [ABSTRACT FROM AUTHOR]

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The article examines the relevance of piezoceramic spherical shell actuators, which provide a high level of accuracy and stability in the generation of vibrational oscillations over a wide range of amplitude-frequency characteristics. The spherical shape of these actuators is chosen because it allows for uniform distribution of mechanical stresses across the actuator's surface, thereby enhancing its durability and efficiency compared to traditional flat or cylindrical designs. The study presents analytically derived mathematical models and formulas for determining the electrical impedance of piezoelectric elements and analyzes the dependence of the amplitude of electrical impedance on frequency and the charge ratio on the polarized surfaces of the spherical piezoceramic element. The proposed model enables the determination of electrical impedance as a function of cyclic frequency and various parameters (geometric, physical and mechanical, electrical) of the actuators. The study establishes that spherical shell actuators exhibit a higher quality factor (2-2.5 times greater than disk actuators and 1.4-1.8 times greater than cylindrical actuators) and a significant reduction in impedance (2.5-7 times lower) at electromechanical resonance frequencies around 2.4 kHz. Furthermore, spherical actuators demonstrate 20-30 % better resistance to deformation and 15-25 % lower susceptibility to local resonances compared to other actuator shapes, which enhances operational stability and vibration generation accuracy. [ABSTRACT FROM AUTHOR]

Computed tomography (CT), magnetic resonance imaging (MRI), and radiography expose patients to electromagnetic fields (EMFs) and ionizing radiation. As an alternative, Electrical Impedance Tomography (EIT) offers a less EMF-influenced method for imaging by measuring superficial skin currents to provide a map of the body's conductivity. EIT allows for functional monitoring of anatomical regions using low electromagnetic fields and minimal exposure times. This paper investigates the application of EIT for the morphological and functional assessment of tissues. Using the Finite Element Method (FEM) (Comsol 5.2), both two-dimensional and three-dimensional models and simulations of physiological and pathological tissues were developed to replicate EIT operations. The primary objective is to detect carcinoma by analysing the electrical impedance response to externally applied excitations. An eight-electrode tomograph was utilised for this purpose, specifically targeting epithelial tissue. The study allowed the characterisation of tomographs of any size and, therefore, the possibility to verify both their geometric profile and the ideal value of the excitation current to be delivered per second of the type of tissue to be analysed. Simulations were conducted to observe electrical impedance variations within a homogeneously modelled tissue and a carcinoma characterized by regular geometry. The outcomes demonstrated the potential of EIT as a viable technique for carcinoma detection, emphasizing its utility in medical diagnostics with reduced EMF exposure. [ABSTRACT FROM AUTHOR]

Understanding the thermal aging kinetics of animal oils is of vital importance in the storage and applications of animal oils. In this work, we use four different techniques, including UV-Vis spectrometry, viscometry, impedance spectroscopy, and acid–base titration, to study the thermal aging kinetics of tallow, chicken oil, lard, and sheep oil in the temperature range from 120 °C to 180 °C. The evolutions of the UV-Vis absorbance, dynamic viscosity, electric impedance, and acid titration are discussed with the defect kinetics. The evolutions of the color centers, defects for dynamic viscosity, and electric dipoles follow second-order, first-order, and zero-order kinetics, respectively. The temperature dependence of rate constants for the evolutions of the UV-Vis absorbance, dynamic viscosity, electric impedance, and acid titration satisfies the Arrhenius equation with the same activation energy for individual animal oils. The activation energies are ~43.1, ~23.8, ~39.1, and ~37.5 kJ/mol for tallow, chicken oil, lard, and sheep oil, respectively. The thermal aging kinetics of the animal oils are attributed to the oxidation of triglycerides. [ABSTRACT FROM AUTHOR]

Ferroelectric polymer-based separators, known for their flexibility, ease of synthesis, and modifiability through dopants, are currently under extensive study due its potential applications in electronic devices. PVDF nanocomposites, which combine the strengths of their constituents, currently lead in emerging technologies. This research employs Zinc oxide nanoparticles (ZnO NPs) as fillers in the PVDF matrix and investigates their structural, optical, thermal and electrical properties. ZnO NPs synthesized via the combustion method, are being incorporated with varying concentrations (2, 4, 6, 8, and 10 wt%), into PVDF nanocomposite (PNC) thin films through a solution casting process. The PNC thin films are characterized using XRD, FTIR, UV–Vis spectroscopy and thermogravimetric analysis (TGA). Dielectric properties are being explored across a frequency range from 20 to 2 MHz at room temperature, revealing enhanced dielectric constants at lower frequencies, decreasing with frequency due to Maxwell–Wagner interfacial polarization. With increasing frequency, AC conductivity and electric modulus exhibit enhancement. Complex impedance analysis via the Cole–Cole plot indicates a non-Debye type of dielectric relaxation with heightened conductivity. TGA demonstrates improved thermal stability in PNC thin films. These findings suggest the potential application of the prepared PNC thin films as separators in energy storage devices. [ABSTRACT FROM AUTHOR]

Parylene C is a common substrate and encapsulation material used in implantable microelectrodes. Its reliability and failure are of great significance in the research and application of microelectrodes. In this study, three different failure stages of Parylene C thin-film electrodes were modeled using equivalent circuits, and the electric impedance spectroscopy of the electrodes were rapidly analyzed 9 different machine learning algorithms to identify the failure stages. The results showed that the three equivalent circuit models (ECMs) can represent the dynamics of the three failure stages of the Parylene C thin-film electrodes. The support vector machine (SVM) algorithm achieves more than 93% accuracy in identifying the ECMs from electric impedance spectroscopy data with an average time of 0.0273 s. The SVM algorithm has great potential in fast analysis of electric impedance spectroscopy for the endurability study and application of implantable microelectrodes. [ABSTRACT FROM AUTHOR]

This study reports the preparation of ZnCo 2 O 4 oxide (ZCO) electrode materials with favorable microstructure and porosity arrangement via ultrasonic electrodeposition-calcination. The application of ultrasonic waves at a power of 200 W (using ZCO-2) led to the development of a smooth and flat microstructure, characterized by the presence of numerous micropores. The lattice constant of ZnCo 2 O 4 in the ZCO-2 oxide electrode material was determined to be 0.428 nm via TEM analysis. Furthermore, the XRD analysis of ZCOs demonstrated the effective synthesis of ZnCo 2 O 4 electrode materials. The main lattice diffraction planes of ZCOs were observed at (111), (220), (311), (400), (511), and (440), with corresponding diffraction angles of 29.8°, 36.4°, 42.9°, 45.2°, 62.3°, and 66.5°, respectively. The application of 200 W ultrasonic power during electrochemical experiments significantly improved the electrochemical performance of ZCO-2. The ZCO-2 oxide electrode demonstrated remarkable area capacitance and negligible electrical impedance. At a current density of 3 mA/cm2, the area capacitance was measured to be 1.803 F/cm2. The ZCO-2 oxide electrode showed remarkable capacitance retention of 67.3 % even under high current density conditions. Furthermore, the asymmetric supercapacitor composed of ZCO-2 and AC (ZCO-2/AC ASC) showed outstanding electrochemical performance. The ZCO-2/AC ASC showed a capacitance of 5.721 F/cm3 at a current density of 0.5 mA/cm2. Furthermore, it demonstrated an energy density of 68.2 Wh/kg at a power density of 250 W/kg. The capacitor showed consistent performance and retained 63.8 % of its initial capacitance even after undergoing 24,000 cycles. Furthermore, the findings of this research provide substantial implications for the combination of ultrasonic electrodeposition with capacitors, while also presenting an innovative concept for electrode materials in high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

The ceramic Sr(NiNb)0.5O3, incorporating silver doping in the A site, was synthesized using a sol–gel route and subjected to comprehensive analysis through various experimental techniques. X-ray diffraction data analysis indicates a rhombohedral crystal structure. Scanning electron microscopy (SEM) examination reveals densely packed grains with minimal surface porosity. A thorough investigation of electrical properties, encompassing dielectric constant, loss tangent, electrical impedance, modulus, conductivity, etc., was conducted across a wide frequency range (103–106 Hz) and temperature range (260–340 K). This analysis provided valuable insights into structure–property relationships and conduction mechanisms. The discussion highlights the significance of interface effects, space charge polarization, and Maxwell–Wagner dielectric relaxation in achieving the material's high dielectric constant at low frequencies and elevated temperatures. Examination of temperature dependence through Nyquist plots elucidates the contributions of grain behavior to the material's resistive and capacitive properties. The dielectric permittivity, dissipation of energy, and electrical characteristics like impedance, modulus and conductivity are notably influenced by the frequency of the applied electric field and temperature. Overall, the material exhibits promising potential for industrial applications such as energy storage, given its intriguing properties. [ABSTRACT FROM AUTHOR]

In this research, a new approach to safeguard against Loss of Field (LOF) in a synchronous generator, in the presence of a series compensation capacitor, is introduced. LOF can lead to detrimental effects on both the generator and the power network. Impedance-based negative and positive offset MHO relays are employed for the rapid recognition of LOE occurrences in the network. However, issues arise when a series compensation capacitor is integrated into the system, causing maloperation of the protection relays. The introduction of the series compensation capacitor alters the total impedance value, necessitating adjustments to the relay settings for precise functionality. The variation in the overall impedance of the system leads to the underreaching and overreaching of a relay. The study provides detailed explanations and comparisons of both types of MHO relays, along with their respective settings. A simulation is applied in DIGSILENT to assess the effect of series compensation capacitors on offset MHO (negative and positive) relay LOF protection. Ultimately, the article concludes by summarizing the pros and cons of both relay schemes. [ABSTRACT FROM AUTHOR]

Milk has a high nutritional value and is also one of the most versatile products in the food industry. Unfortunately, fraud involving the product is constant and needs to be combated. This work presents a measurement methodology to perform the electrical impedance analysis in food. The influence of temperature on the measurements has been evaluated through mathematical models specially developed for identifying the fraudulent activity of adding water to milk. The bioimpedance measurements have been performed in a sample container with a four-electrode measurement system and a digital oscilloscope. Samples of 150 mL were analysed, prepared using whole UHT milk adulterated with distilled water in different % by volume (V/V), at temperatures of 16, 28, and 37 °C. The proposed measurement methodology has been validated and showed sensitivity for analysis in milk, revealing the influence of temperature on the impedance values; from the results mathematical models were proposed for investigating adulteration in milk. This work deals with the design of a device capable of measuring bioimpedance in milk with a view to its application in physicochemical analyses. The influence of temperature on the impedance values was also evaluated to propose mathematical models to facilitate analysis with complex factors and matrices. [ABSTRACT FROM AUTHOR]

Overweight and obesity have increased significantly worldwide, placing major economic problems on health systems. This study aims to determine socio-economic characteristics, dietary practices, physical activity levels, nutrition status, predictors of overweight and obesity, and their relationships among adolescents. Methods: The study adopted a cross-sectional analytical study design. 401 adolescents were randomly selected from five secondary day schools using a proportionate-to-size sampling method. Results: Based on the findings, one third (36.3%) of the adolescents were between ages 17-18, with more girls (55.9%) than boys. The number of meals consumed per day among adolescents was 3.34±1.24. Individual dietary diversity score among adolescents was 4.21±1.61. Based on Body Mass Index (BMI), the prevalence of overweight and obesity among boys was 5.2% and 1.8%, respectively, and for girls, it was 7.3% and 3.6%, respectively. Using bioelectrical impedance analysis, the prevalence rates for males were 8.8% and 4.1%, respectively, while for females the rates were 10.1% and 5.1%. Regression analysis revealed that the most significant predictors were energy intake and physical activity, with P˂0.05 based on BMI and bioelectrical impedance analysis. Conclusion: There is a significant relationship between nutritional status and energy intake, the number of meals, dietary diversity score, and physical activity. Physical activity and dietary practices were the most important predictors of overweight and obesity among adolescents. The study recommends nutrition education and public health interventions in schools’ curricula.