Conductivity Parameters Research Articles

Generalized thermoelastic damping in micro/nano-ring resonators undergoing out-of-plane vibration

Micro/nano-ring or ring-based resonators are popular core components of sensors and actuators. Accurately predicting the quality factor (Q) based on thermoelastic damping (TED) is intensively crucial for designing high-performance micro/nano-ring resonators. In this work, adopting the modified-couple-stress (MCS) and nonlocal-dual-phase-lagging (NDPL) models, analytical TED expressions are developed for circular cross-section micro/nano-rings undergoing out-of-plane vibration for the first time. Multiple effects are considered in the modeling procedure, which are size-dependence effects in the mechanical and thermal fields, the non-Fourier effect of heat conduction, and three-dimensional temperature gradients in the circumferential, radial, and tangential directions. Therefore, the proposed TED models are more comprehensive compared to existing TED models. The coefficients (CC and CM) associated with the out-of-plane vibration mode are examined from an energy-ratio perspective. Moreover, the investigation is focused on the impacts of the MCS and NDPL non-Fourier effects on the fluctuation temperature and TED spectra. The results indicate as CC and CM approach one, the bending energy emerges as the predominant component of the stored energy. Notably, the NDPL non-Fourier effect significantly affects the fluctuation temperature within the ring operated in high-order modes. In special, the distributions of fluctuation temperature in the circumferential direction exhibit periodic patterns that are closely correlated with the modal order. Furthermore, TED can be suppressed by the MCS size-dependence effect. Meanwhile, the behavior of TED at high frequencies is simultaneously determined by the dimension of heat conduction, phase-lagging times, and nonlocal thermal-length parameter.

Entropy optimized radiative flow conveying hybrid nanomaterials [formula omitted] with melting heat characteristics and Cattaneo-Christov theory: OHAM analysis

Here flow for radiative hybrid-nanomaterial (MgO+MoS2) satisfying Darcy-Forchheimer relation is addressed. Ethylene glycol C2H6O2 is utilized as a base fluid. Magnesium oxide (MgO) and Molybdenum disulfide (MoS2) are considered as distinct nanoparticles. Thermal expression is examined through heat generation and viscous dissipation. Analysis for Cattaneo-Christov theory is carried out. Condition for melting heat is deliberated. Entropy generation is examined. Variable thermal conductivity of hybrid nanomaterial is taken. Suitable transformations are implemented to obtain nonlinear dimensionless systems. Optimal homotopy analysis method (OHAM) is implemented for computations. Temperature, velocity and entropy generation are scrutinized physically. Nusselt number and skin friction are discussed. Conclusion synthesis salient points. Present work is relevant in metallurgical engineering and polymer processing. The findings conclude that Forchheimer number correspond to decline in velocity. Entropy rate and thermal field have similar trend for heat generation variable. A decrease in velocity against melting variable is noted. Temperature increases for variable thermal conductivity and thermal relaxation parameters. Entropy optimization improved for Brinkman number. Skin friction decays for porosity parameter and Forchheimer number. Skin friction improves for melting variable and Forchheimer number. Entropy augments against higher thermal relaxation time. Higher melting variable lead to an enhancement for Nusselt number. There is an improvement for radiation through Nusselt number and temperature.

Analysis the Effect of Flux and Water Characteristics on Polyethersulfone Ultrafiltration Membrane Performance as Pre-Treatment of SWRO

Increasing human population resulted in higher demand for potable freshwater, while freshwater sources were limited. As an alternative solution, seawater was necessarily to be employed as a main source of water supply and necessarily treated with Seawater Reverse Osmosis (SWRO). However, membrane fouling of SWRO was occurred. Therefore, implementation of ultrafiltration membranes as pre-treatment were necessary. In this study, identification of removal efficiency seawater characteristics of TDS, COD, conductivity, and UV-Vis parameters at different flux and investigation of the fouling rate at variations filtration performance of the 50 kDa MWCO pore size PES ultrafiltration membrane was performed. Filtration of laboratory scale experiment with constant flux of 120 L/m²⋅h and 180 L/m²⋅h at dead-end operation was performed. Filtration of 50 kDa PES ultrafiltration membrane was able to remove effectively turbidity, TDS, UV-Vis, conductivity, and COD with 63±6%; 37±19%; 7±4%; 33±33%; dan 97.86%, respectively. Furthermore, related to membrane performance, filtration at 120 L/m²·h flux operation was found as the common fouling mechanisms, while flux operation at 180 L/m²·h resulted different behavior resulted for severe membrane performance. The suitable operation of fluxes 120 L/m²·h was recommended to increase the performance and membrane lifespan as well as to decrease the load of SWRO unit.

Mixed convective viscous dissipative flow of Casson hybrid nanofluid with variable thermal conductivity at the stagnation zone of a rotating sphere

AbstractMixed convection flows across the revolving bodies have eminent applications in science and technology, such as fibre coating, polymer deposition, centrifugal blood pumps, rotatory machinery, and so forth. In the current work, magnetohydrodynamic (MHD) flow and heat transfer characteristics of Casson hybrid nanofluid (Ag/MgO as nanoparticles) over the rotating sphere at the stagnation zone are being studied. Moreover, an analysis of heat transmission is conducted by considering the influence of thermal radiation, temperature‐dependent thermal conductivity, magnetic field, and viscous dissipation. The relevant partial differential equations are reformed into ordinary differential equations by appropriate transformations, which are solved using the successive linearization method (SLM). The thermal field, velocity components in x and z directions, heat transfer rate, and skin friction coefficient are computed for various physical quantities like rotation parameter mixed convection parameter, radiation parameter, Eckert number, Casson parameter, magnetic parameter, variable thermal conductivity parameter, and so forth. The current findings align well with the literature in a limiting sense. Thermal enhancement in hybrid nanofluid is observed for the viscous dissipation parameter (Ec), thermal conductivity parameter (), and radiation parameter (Rd). The degree of heat transfer rises from 12.8% to 20% when the Casson parameter's value () increases. Also, a decrease of approximately 33% is depicted between the peak values of the velocity magnitude with an increase in rotation parameter.

Dynamic simulation of unsteady Casson–Carreau fluid flow considering temperature-dependent variable-properties and thermo-solutal mixed convection over flat and slendering sheets

The present investigation delves into the intricate interplay between surface effects and fluid dynamics, focusing on the flow characteristics of Casson and Carreau fluids endowed with temperature-dependent thermophysical properties. Specifically, the study explores the ramifications of radiative, mixed convection, and magnetized processes on heat and mass transfer phenomena. A comprehensive mathematical model is developed to analyze the behavior of Casson–Carreau fluids in conjunction with microscopic particles and gyrotactic microorganisms over both flat and slender surfaces. Leveraging similarity transformations, the governing equations are transformed into dimensionless form, facilitating numerical solutions using the bvp5c solver in MATLAB. The ensuing numerical and graphical analyses elucidate key physical quantities, including local skin friction coefficients, gyrotactic microorganism density, Nusselt number, and Sherwood number, across a spectrum of physical parameters. Notably, the investigation underscores the profound influence of flat surfaces on flow patterns and highlights the heightened consumption of fluid particles with increasing variable diffusivity and thermal conductivity. Moreover, enhanced values of parameters such as variable motile microorganism diffusion coefficient, Brownian motion parameter, and temperature-dependent thermal conductivity parameter are found to augment the Nusselt number, indicative of intensified heat transfer rates. This research underscores the imperative of comprehending the intricate dynamics of fluid flow and heat transfer, offering actionable insights for enhancing engineering designs and addressing multifaceted challenges across domains encompassing chemical engineering, environmental science, and biomedical applications.

Electrophysiological Assessment of Paresthesia in Patients Following Radial Angiography: AProspective Study.

Radial angiography, preferred for its safety and comfort in percutaneous coronary interventions, occasionally leads to paresthesia-a tingling or numbing sensation in the hand. This study aimed to investigate the presence of nerve damage in patients experiencing paresthesia post-radial angiography through electrophysiological examination. This prospective study involved 77 patients who developed hand paresthesia following radial angiography. Excluded were those with malignancy, pregnancy, pace-makers, or recent angiography. Nerve conduction studies were performed using the Neuropack MEB 9102K EMG device, assessing sensory and motor amplitudes, latencies, and velocities of median, ulnar, and radial nerves. The study included 77 patients (23 females, 54 males; average age 58.39 ± 10.44 years). In 11 diabetic patients, polyneuropathy was detected. For the remaining 66 patients, electrophysiological evaluations showed no significant pathological findings. Comparative analysis of both upper extremities revealed no significant differences in nerve conduction parameters between the side where angiography was performed and the other side. Despite paresthesia complaints, no electrophysiological evidence of nerve damage was found, suggesting that symptoms might be due to local irritation rather than direct nerve injury. This aligns with the safety profile of radial angiography and underscores the importance of distinguishing between transient paresthesia and serious nerve complications. Paresthesia post-radial angiography, while clinically notable, is not typically associated with nerve damage. This study is significant as it is the first in the literature to demonstrate that radial angiography does not cause nerve damage.

Optical and Dielectric Features of PVA/CMC/PVP/ZnMn2O4/CuCo2O4/x wt% MWCNTs Blended Polymers for Optoelectronic Applications

This study is devoted to optimizing the optical and dielectric parameters of polyvinyl alcohol (PVA)/ carboxymethyl cellulose (CMC)/ polyvinylpyrrolidone (PVP) blended polymer by adding ZnMn2O4/CuCo2O4 nanocomposite and controlling the amounts of multi-walled carbon nanotubes (MWCNTs) to engage them in flexible optoelectronics and storage energy capacitors. Herein, 0.9ZnMn2O4/0.1CuCo2O4 was synthesized by co-precipitation and hydrothermal methods and loaded with different ratios of MWCNTs into PVA/CMC/PVP blend to produce films by solution casting procedure. The crystallite size of 0.9ZnMn2O4/0.1CuCo2O4 was determined using transmission electron microscopy. The structures of the filler and doped blends were explored via the X-ray diffraction technique. The optical features of undoped and doped blends were explored by diffused reflectance and fluorescence spectrophotometers. The addition of ZnMn2O4/CuCo2O4 to PVA/CMC/PVP caused a decline of direct and indirect optical band gaps from 5.33 and 5.03 eV to 5.19 and 4.66 eV, respectively. By adding different amounts of MWCNTs, the direct/indirect optical band gap reduced irregularly, and they attained their minimum values (5.07, 4.46) eV as it doped with 0.6 Wt% MWCNTs. The highest values of refractive index, extinction coefficient, optical conductivity and nonlinear optical parameters were achieved in the blend containing ZnMn2O4/CuCo2O4/0.6 Wt% MWCNTs. It is also found that the dielectric constant and ac conductivity rose with the insertion of ZnMn2O4/CuCo2O4/0.6 Wt% MWCNTs. The highest energy density value was found in the polymer blend of PVA/CMC/PVP/ZnMn2O4/CuCo2O4/0.8 Wt% MWCNTs blended polymer. Electrical modulus and Nyquist plots for different blends were also examined. The results recommend the doped blends as a good candidate for optoelectronics and energy storage capacitor applications.

The electrical and dielectric features of Al/YbFeO3/p-Si/Al and Al/YbFe0.90Co0.10O3/p-Si/Al structures with interfacial perovskite-oxide layer depending on bias voltage and frequency

In this investigation, thin films of YbFeO3, both in its pure form and doped with 10% Co, were fabricated on a p-Si substrate at 500 °C through the radio-frequency magnetron sputtering method. Examination via Scanning Electron Microscopy demonstrated a porous texture for the pure sample, contrasting with a smooth and crack-free surface post-Co doping. Analysis via X-ray photoelectron spectroscopy unveiled Yb’s 3 + oxidation state, alongside the presence of lattice oxygen, oxygen vacancies, and adsorbed oxygen evident in Gaussian fitting curves. Photoluminescence spectroscopy revealed an augmented emission intensity, likely attributed to increased defect initiation in the Co-doped specimen. Moreover, Raman spectroscopy was employed to identify vibration modes in the examined samples, demonstrating shifts in Raman peaks indicative of Co substitution and subsequent distortion in the crystal structure of YbFeO3. Electrical assessments were conducted at room temperature (300 K) under ambient conditions, employing voltage and frequency as variables. Capacitance–voltage measurements illustrated the emergence of an accumulation, with depletion and inversion regions manifesting at different frequencies based on the applied voltage, attributed to the YbFeO3 interfacial layer at the Al and p-Si interface. The conductance-voltage characteristics indicated that the structure exhibited maximum conductance in the accumulation region. Series resistance for these configurations was deduced from capacitance-conductance-voltage measurements, indicating a dependence on both bias voltage and frequency. The doping process led to a reduction in capacitance and series resistance, accompanied by an increase in conductance values. After obtaining corrected capacitance and conductance parameters, it became evident that series resistance significantly influences both parameters. Interface state density (Nss), determined through the Hill-Coleman relation demonstrated a decreasing trend with increasing frequency. The pure sample exhibited higher interface state density compared to the Co-doped sample at each frequency, highlighting that the 10% Co-doped YbFeO3 thin film enhances the quality of the metal–semiconductor interface properties compared to the pure contact.

Dynamic synchronization optimization of beef atmosphere packaging system

Modified atmosphere packaging (MAP) of beef is a key tool to ensure its post-production shelf life. However, it is still a technical challenge to realize intelligent, dynamic, modified-atmosphere packaging of beef products on the production line to improve production and packaging efficiency. In this paper, we propose a dynamic and synchronized modified atmosphere packaging optimization strategy for beef based on admittance control. The purpose of synchronized, accurate, and efficient modified-atmosphere packaging of beef is achieved. Firstly, particle swarm optimization was designed to optimize the conductance parameters, which did not achieve good optimization results, so a whale optimization algorithm based on inertia weights as well as teaching strategy improvement was designed for optimization, and simulation analysis was carried out. The most important parts of the packaging process were also tested, such as the effect of synchronous following motion, the stability and ability to block interference, the accuracy of the Cartesian Coordinate Robot's repeated positioning, and the system's overall operation performance. The results show that the synchronous following error of the system is ±1%, and after the optimization of the improved whale optimization algorithm, the conduction model is reduced in both overshooting amount and regulation time, which improves the performance of the closed-loop following motion model. And the beef dynamic modified atmosphere packaging system, with the application of the algorithm, can complete the modified atmosphere packaging work stably, accurately, continuously, and efficiently.

Heat transfer investigation of nano – Encapsulated phase change materials (NEPCMs) in a thermal energy storage device

Phase change natural convection heat transport and flow features of a variety and new types of hybrid nanoliquids, suspension of Nano – encapsulated phase change materials (NEPCMs), within a square cavity is inspected theoretically in this analysis. The capsules are arranged with a shell and a PCM as a core. The shell of this NEPCM prevents the phase change material from the direct interaction of hot fluid and from the leakage. The heat capacity of the suspension contains latent heat generated at the time of phase change. The modeled equations are numerically scrutinized with Finite element method. Variable thermal conductivity parameter 1≤Nc≤5, variable viscosity parameter 1≤Nv≤5, radiation number 0.5≥R≥0.1, Rayleigh parameter 102≤Ra≤103, volume fraction of NEPCMs1%≤ϕ≤5% and fusion temperature (0.2≤θf≤1.0) impact on the patterns of heat capacity ratio, isotherms and velocity lines are examined in detail. The results indicates that, as the volume fraction values of NEPCMs amplifies from 1% to 5% the rates of heat transfer of the nanoliquid magnifies 42% compared to the host fluid. Non – dimensional rates of heat transport magnifies with growing (Ste) values.

Impact of electro-osmotic, activation energy and chemical reaction on Sisko fluid over Darcy–Forchheimer porous stretching cylinder

This study provides numerical solution for two-dimensional electro-osmotically motivated electro-magneto-hydrodynamic Sisko fluid through an elongating porous cylinder. The electro-osmotic, activation energy with chemical reaction are also interpreted for this flow model. The numerical equations that govern this flow problem are renewed into dimensionless form by applying appropriate transformations exploiting Runge–Kutta–Fehlberg fifth order through shooting technique method. The after-effects are illustrated as graphs for the concerned physical parameters and their impact on convection and conduction is also studied. The velocity rises for electro-osmotic parameter whereas drops for magnetic and porous parameter. The temperature shows an increasing profile for the curvature, electric and thermal conductivity parameter while decreases for Prandtl number. The concentration of nanoparticles in the fluid boosts for activation energy but deflates for curvature parameter. The present findings appear to be in good accord when compared to earlier published studies. Numerous opportunities and applications are presented by applying electro-osmotic forces to non-Newtonian fluid flow, especially in the fields of nanotechnology, electro-kinetics and micro-fluids. The current study can be applied to design effective electro-magnetic devices, particularly in certain thermal transport characteristic regime. The main findings demonstrate the great utility of electro-osmosis in micro-fluidic devices, chemical analysis, soil analysis and cement slurries for managing flow and heat transmission.

Improving the optical and dielectric characteristics of PVA/PVP/PEG/ZnWO4/CdS blends

This work aims to create novel nanocomposite blended polymers by incorporating (1−x)ZnWO4-xCdS into poly (vinyl alcohol) (PVA)/polyvinyl pyrrolidone (PVP)/polyethylene glycol (PEG) blend to employ these nanocomposites in various optoelectronic applications. This study focused on investigating the structural, optical and electrical features of PVA/PVP/PEG/(1−x)ZnMn2O4-xCdS blends. The x-ray diffraction and scanning electron microscope techniques were used to explore the structure and morphology of the formed samples. The structure and percentages of ZnWO4 and CdS in different fillers were performed using Rietveld method. The doped blends exhibited significant absorption of UVA and UVB types. The greatest amounts of absorption were observed when the filler contained 25 % CdS. The direct and indirect optical band gaps of the doped blend became 5.02 and (1.88, 2.37) eV as the amount of CdS became 25 % in the filler sample. The refractive index, optical dielectric constant, optical conductivity, and nonlinear optical parameters are affected by the amount of CdS in the fillers. The fluorescence spectra for the blends affected by the excitation wavelength and amount of CdS in the filler. The maximum energy density of the doped blend was reached when the amount of CdS in the filler reached 25 %. The purities of emitted color in the undoped blend are 83 % and 74 % under excitation wavelengths of 317 nm and 380 nm. The purity of the blend experienced a slight change when loaded with filler samples. As the ZnWO4 doping of the PVA/PVP/PEG blended polymer rose, its electrical dielectric constant and ac conductivity first enhanced and then irregularly declined as the filler's CdS content rose. Incorporating (1−x)ZnWO4-xCdS into the nanocomposite enhanced their optical and electrical properties, making them a potential material for flexible optoelectronic and energy storage uses.

Development and validation of the Atri-Risk Conduction Index risk score to predict risk of atrial fibrillation after typical atrial flutter ablation

BackgroundIdentification of patients at risk for atrial fibrillation (AF) after typical atrial flutter (tAFL) ablation is important to guide monitoring and treatment. ObjectiveThe purpose of this study was to create and validate a risk score to predict AF after tAFL ablation MethodsWe identified patients who underwent tAFL ablation with no AF history between 2017 and 2022 and randomly allocated to derivation and validation cohorts. We collected clinical variables and measured conduction parameters in sinus rhythm on an electrophysiology recording system (CardioLab, GE Healthcare). Univariate and multivariate logistic regressions (LogR) were used to evaluate association with AF development. ResultsA total of 242 consecutive patients (81% male; mean age 66 ± 11 years) were divided into derivation (n =142) and validation (n = 100) cohorts. Forty-two percent developed AF over median follow-up of 330 days. In multivariate LogR (derivation cohort), proximal to distal coronary sinus time (pCS-dCS) ≥70 ms (odds ratio [OR] 16.7; 95% confidence interval [CI] 5.6–49), pCS time ≥36 ms (OR 4.5; 95% CI 1.5–13), and CHADS2-VASc score ≥3 (OR 4.3; 95% CI 1.6–11.8) were independently associated with new AF during follow-up. The Atri-Risk Conduction Index (ARCI) score was created with 0 as minimal and 4 as high-risk using pCS-dCS ≥70 ms = 2 points; pCS ≥36 ms = 1 point; and CHADS2-VASc score ≥3 = 1 point. In the validation cohort, 0% of patients with ARCI score = 0 developed AF, whereas 89% of patients with ARCI score = 4 developed AF. ConclusionWe developed and validated a risk score using atrial conduction parameters and clinical risk factors to predict AF after tAFL ablation. It stratifies low-, moderate-, and high-risk patients and may be helpful in individualizing approaches to AF monitoring and anticoagulation.

Can hydraulic-energy-indices be effectively used to describe the saturated hydraulic conductivity?

The saturated hydraulic conductivity (Ks) and water retention curve (SWRC) parameters are important properties for simulating soil hydrological processes and characterizing soil conservation around the world. Therefore, Ks and SWRC are related with the soil physical quality (SPQ) and several SPQ indices can be derived from SWRC, such as the pore size distribution, relative field capacity, plant available water, drainable porosity, and soil hydraulic-energy indices (SHEI). It is well known that the soil structure can be assessed by using SHEI, but a possible physical relationship between Ks and SHEI was not examined yet. Therefore, the objective of this study was to investigate the behavior of Ks as function of SHEI for several soil textural classes. If this relationship be proved, then SHEI might be applied to improve the Ks prediction by PTF models. In this work, a data set of 395 measured SWRC's were fitted to the vG equation to obtain the SHEI to verify whether they are statistically correlated and physically dependent on Ks. The resulting parametric and non-parametric correlation results were split up according to six textural classes. The significant influence of Ks on at least one of the absolute SHEI (Aa or WRa) was verified on the numerical scale when all textures were grouped and on numerical and pF scales for clayey and silty textures. Ks showed significant impact on Aa and WRa indices in four textural classes. Furthermore, Ks had influence on the sum Aa + WRa denoted in pF scale for five of the six textural classes, with a significant linear correlation in the clayey texture when log (Aa + WRa) was applied. The significant and high correlation of Ks on the ratios WRa/AWC and Aa/φD was also observed in four of the six classes, and therefore the use of these indices is recommended for the development of PTFs for Ks prediction.

Exploring the impact of solvent additives on dielectric properties in polymer photovoltaics: A deconvolution and in-depth study of electrical modulus, complex conductivity, and impedance responses

Impedance and dielectric spectroscopy is a well-known technique for characterizing interfaces, especially donor/receiver interfaces in bulk heterojunction (BHJ) solar cells. This technique was employed to investigate the interface of poly (4,8-bis-alkyloxybenzo(1,2-b:4,5-b0) dithio-phene-2,6-diyl-alt- (alkyl thieno (3,4-b) thiophene-2-carboxylate)-2,6-diyl) (PBDTTT-C): PC70BM in bulk heterojunction with DIO as additive. For this reason, a simulation was carried out to generate the complex impedance, modulus, and complex conductivity data based on the electrical parameters extracted from the equivalent circuit. Therefore, a new approach based on the coupling of complex functions such as impedance, modulus, and conductivity has been proposed. In addition, an extrapolation and deconvolution approaches are used to highlight the relaxation processes, the BHJ layer process, the two electrical contacts of the interfaces between PEDOT: PSS/PBDTTT-C: PC70BM and PBDTTT-C: PC70BM/Ca process, and the electrode polarization process. In the next step, the remove the low-frequency process enhances the visibility of other processes, particularly observable in the evolution of the electrical modulus and the conduction parameters associated with each process. In the complex functions, there was a good correlation between all parameters derived from both processes. The characteristics of the conduction processes, such as conductivity values at low and high frequencies and ionic strength were then extracted. All these parameters were evaluated and discussed as a function of the thickness of the active layer. Finally, we demonstrate that the electrical modulus and complex conductivity can be perfect tools to characterize the donor/acceptor interfaces.

Characterization and the physical properties of nano-sized Bi2O3/polymer for energy and high-refractive index applications

The present work focuses on developing nanocomposites for optoelectronics and energy storage devices leveraging the unique physicochemical features of bismuth (III) oxide (Bi2O3) using a polyvinyl pyrrolidone/polyvinyl alcohol matrix (PV(A/P)). Bi2O3 nanofillers (NF) and Bi2O3/PV(A/P) nanocomposite (NC) films were prepared by facile chemical solution approaches. The X-ray (XRD) data and a transmission electron image revealed that the NF exhibits a monoclinic phase, resembling slightly deformed agglomerated spheres. In the FTIR spectrum, different stretching vibrations of Bi-O-Bi bonds were found, along with their complexation and interaction with the reactive groups in the matrix. The SEM revealed a uniform distribution of Bi2O3 NF loading up to 1.5 wt% on the sample’s surface. Thermal analyses (TGA and DSC thermograms) were used to study the thermal stability, melting, and decomposition temperatures of the NC films. The dielectric features were studied under frequencies between 2 × 103 and 8 × 106 Hz and heating from 293 to 393 K. The dielectric constant and energy density were increased with Bi2O3 NF content. This implies that we can utilize the prepared NC for the fabrication of energy storage devices. The influences of the Bi2O3 NF doping level on the transmittance, band gap, Urbach energy, refractive index, conductivity, and other physical parameters were discussed. The modifications induced in the dielectric/optical parameters make the prepared NC films the best candidates for applications requiring a high refractive index, such as optical coatings and integrated photonic devices.

Reflection of Waves in a Two-Temperature Magneto-fiber-Reinforced Solid with Memory-Dependent Derivative Using Different Theories

Abstract Purpose The problem is concerned with the analysis of the reflection of the waves through a fiber-reinforced thermoelastic medium under the effect of the magnetic field, gravity, and the initial stress. The problem is discussed in the context of the three-phase-lag model and Green-Naghdi theory of type II and III with the memory-dependent derivative and variable thermal conductivity. Methods The harmonic representation of waves is used to find the solution to the problem. Based on the solution, it is concluded that after reflection three quasi-waves propagate through the medium. Results Numerical computations were performed using MATLAB software. The reflection coefficient ratio variations with the angle of the incident are shown graphically. Conclusion Comparisons are made with the results predicted for different values of the thermal conductivity parameter, two-temperature parameter, initial stress, gravity field, and different values of the magnetic field.

A multidimensional AI-trained correction to the 1D approximate model for Airborne TDEM sensing

The computational resources required to solve the full 3D inversion of time-domain electromagnetic data are immense. To overcome the time-consuming 3D simulations, we construct a surrogate model, more precisely, a data-driven statistical model to replace the 3D simulations. It is trained on 3D data and predicts the approximate output much faster. We construct a surrogate model that predicts the discrepancy between a 1D subsurface model and a deviation of the 1D assumption. The latter response is fastly computable with a semi-analytical 1D forward model. We exemplify the approach on a two-layered case. The results are encouraging even with few training samples. Given the computational cost related to the 3D simulations, there are limitations in the number of training samples that can be generated. In addition, certain applications require a wide range of parameters to be sampled, such as the electrical conductivity parameters in a saltwater intrusion case. The challenge of this work is achieving the best possible accuracy with only a few thousand samples. We propose to view the performance in terms of learning gain, representing the gain from the surrogate model whilst still acknowledging a residual discrepancy. Our works open new avenues for effectively simulating 3D TDEM data.

Multi-scale ground penetrating radar full waveform inversion with hybrid Tikhonov and total-variation regularization for different geometric structure

Abstract Full waveform inversion (FWI) is a high-resolution technique to estimate the parameters of dielectric permittivity (ϵ) and electrical conductivity (σ) and identify the structure of the subsurface for Ground Penetrating Radar (GPR) application. However, permittivity and conductivity parameters can be coupled in bi-parameter GPR inversion. This coupling effect leads to the crosstalk in the FWI result. To solve this problem, we propose a novel approach to use the multi-scale FWI with the hybrid regularization method, which combines Tikhonov and total-variation (TV) regularizers that simultaneously invert the ϵ and the σ parameters, which improve the inversion accuracy and reduce the crosstalk effect. The multi-scale strategy uses the Wiener filtering to process the GPR data in different frequency ranges. Then, the low frequencies signal updates the bottom part and subsequently increases the frequencies to invert for the shallow areas. The Tikhonov regularization stabilizes the reconstruction of the smoothly varying background part. In contrast, Total Variation (TV) regularization can recover the large contrasts associated with the LNAPL model. The new Tikhonov-TV (TT) regularization can mitigate the crosstalk caused by the parameter coupling effect. Numerical tests with typical GPR models demonstrate that the proposed multi-scale TT-FWI strategy can effectively eliminate the crosstalk and improve the reconstruction accuracy when the model parameters have a different structure.

Modeling and simulation for prediction of multiple sclerosis progression

In light of extensive work that has created a wide range of techniques for predicting the course of multiple sclerosis (MS) disease, this paper attempts to provide an overview of these approaches and put forth an alternative way to predict the disease progression. For this purpose, the existing methods for estimating and predicting the course of the disease have been categorized into clinical, radiological, biological, and computational or artificial intelligence-based markers. Weighing the weaknesses and strengths of these prognostic groups is a profound method that is yet in need and works directly at the level of diseased connectivity. Therefore, we propose using the computational models in combination with established connectomes as a predictive tool for MS disease trajectories. The fundamental conduction-based Hodgkin-Huxley model emerged as promising from examining these studies. The advantage of the Hodgkin-Huxley model is that certain properties of connectomes, such as neuronal connection weights, spatial distances, and adjustments of signal transmission rates, can be taken into account. It is precisely these properties that are particularly altered in MS and that have strong implications for processing, transmission, and interactions of neuronal signaling patterns.The Hodgkin-Huxley (HH) equations as a point-neuron model are used for signal propagation inside a small network. The objective is to change the conduction parameter of the neuron model, replicate the changes in myelin properties in MS and observe the dynamics of the signal propagation across the network. The model is initially validated for different lengths, conduction values, and connection weights through three nodal connections. Later, these individual factors are incorporated into a small network and simulated to mimic the condition of MS. The signal propagation pattern is observed after inducing changes in conduction parameters at certain nodes in the network and compared against a control model pattern obtained before the changes are applied to the network. The signal propagation pattern varies as expected by adapting to the input conditions. Similarly, when the model is applied to a connectome, the pattern changes could give an insight into disease progression. This approach has opened up a new path to explore the progression of the disease in MS. The work is in its preliminary state, but with a future vision to apply this method in a connectome, providing a better clinical tool.