Double Diffusion Research Articles

Resistance profiles of carbapenemase-producing Enterobacterales in a large centre in England: are we already losing cefiderocol?

Abstract Background Carbapenemase-producing Enterobacterales (CPE) pose difficult therapeutic challenges. We aimed to characterize antimicrobial resistance profiles of CPE in our centre. Methods All non-duplicate CPE isolates between 1 August 2020 and 31 August 2023 in a large teaching trust in England were retrospectively studied. Cefiderocol antimicrobial susceptibility testing (AST) was performed using disc diffusion, ceftazidime/avibactam using disc diffusion and gradient diffusion, and ceftazidime/avibactam aztreonam synergy using the double disc diffusion method. EUCAST version 14.0 breakpoints were used. Results A total of 158 CPE from 136 patients were isolated. Most patients were colonized with CPE, but only 16.9% had active infections. Thirty-day all-cause mortality was 10.3%, increasing to 13% for patients with infections and to 18.2% for bacteraemias. OXA-48 was the most prevalent carbapenemase (48.1%), followed by NDM (38%). All isolates exhibited MDR profiles, with high levels of resistance to meropenem (41.1%). Resistance to cefiderocol was found in 69.7% of NDM-producing isolates, with a further 18.2% in the area of technical uncertainty. Ceftazidime/avibactam and aztreonam synergy was seen in 87.5% of isolates, whereas colistin and fosfomycin susceptibility remained high (98.1% and 97.2%, respectively). All OXA-48-producing isolates were susceptible to ceftazidime/avibactam, and 15.3% were resistant to cefiderocol. No patients had been exposed to cefiderocol beforehand, whereas three had been exposed to ceftazidime/avibactam. The most common risk factor for CPE isolation was travel and receiving healthcare abroad, especially in Asia. Conclusions We found high rates of resistance to cefiderocol in CPE isolates without prior cefiderocol exposure. Our results prohibit empirical use of cefiderocol for the treatment of CPE infections in our setting.

Investigation of heat generation and radiation effects on boundary layer flow of Prandtl liquid with Cattaneo–Christov double diffusion models

In this analysis, a bidirectional stretched sheet is used to produce a 3D\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal{D}$$\\end{document} flow of Prandtl liquid with improve mass diffusion and heat conduction models. This study advances knowledge of magnetohydrodynamics, radiation impacts, and heat production in fluid dynamics and transport processes. The Prandtl fluid model is critical for modeling non-Newtonian fluids, capturing its viscoelastic features, and allowing for precise simulation in industrial applications. It gives a mathematical foundation for analyzing complex fluid behaviors, which is necessary for optimizing operations utilizing such fluids. It uses the boundary layer method to simplify the fundamental equations and Cattaneo–Christov double diffusion models. The optimal homotopy analysis method is used to solve nonlinear ODEs caused by non-dimensional similarity variables. This investigation undertakes the calculation of drag coefficient for surfaces mass transfer rates and heat transfer rates proximate to the solid boundary. Furthermore, it conducts a comprehensive analysis of the influences exerted by various parameters on concentration and temperature profiles employing graphical representations for a rigorous examination. The Prandtl fluid model describes the viscoelastic characteristics of non-Newtonian fluids through constitutive equations, dimensional evaluation, and numerical simulations, which are frequently validated by experiments. The results show that changes in thermal and concentration relaxation parameters are accompanied by a decline in temperature. Temperature field rises as the thermal radiation parameter and heat generation increases. The work's novelty consists in its advanced modeling of Prandtl non-Newtonian fluids via Cattaneo–Christov double diffusion models, which incorporate magnetohydrodynamics and radiation effects and use optimal homotopy analysis for accurate parametric analyses of heat and mass transfer.

Design and experimental verification of a novel high-reliability variation of lateral doping (VLD) termination

Abstract A novel two-dimensional mesh-like variation of lateral doping (VLD) termination (M-VLD) is proposed, which modifies the conventional ring-shaped track VLD termination (R-VLD) mask into an interconnected mesh-like structure. The comparative simulations and experiments show that M-VLD can achieve better blocking capability and reliability than R-VLD. Vertical double diffusion MOSFET (VDMOS) with M-VLD achieves a maximum breakdown voltage ( B V max ) of 1588 V, which is 62 V higher than that of VDMOS with R-VLD. Furthermore, the devices with M-VLD exhibit lower leakage currents in 150 °C reverse-biased I − V test and successfully pass 1000 h-125 °C-1200 V high-temperature reverse bias (HTRB) test, while the devices with R-VLD fail to pass both tests.

Enhancing retention of biological fluid transport of magnetized thermal radiative pseudoplastic nanofluid with double diffusion convection, viscous dissipation and boundary slips

This study investigates how thermal radiation, viscous dissipation, double-diffusive convection, and slip boundaries collectively affect the peristaltic movement of a magneto-pseudoplastic nanofluid within a uniform channel. The inclusion of slip boundary conditions at the channel walls helps to accurately represent the flow behavior of the nanofluid near these boundaries. The magneto-pseudoplastic nanofluid exhibits peculiar rheological features to flow dynamics due to pseudoplastic characteristics of nanoparticles in its composition and exposure to magnetic force. The mathematical formulation of motion equations is done through appropriate technique combining the properties of heat radiation, magnetic flux, double diffusion convection, and rheological features. The equation is further simplified by suitable method. The current study aims to evaluate the peristaltic movement under influence of slip boundaries characteristics, sort of concentration, heat radioactivity, flux properties, and temperature profile. Moreover, it will assess the flow dynamics with ratio of mass and heat exchange under the effect of critical parameters which include Prandtl number, Grashof number, slip limitations, and Hartmann number. So, the research will widen the theoretical underpinning of complex fluid transportation of magneto-pseudoplastic nanofluids under peristaltic flux and explicate the practical outcomes in terms of slip boundary settings in such systems. The results and conclusions are imperative for restructuring and devising biomedicine engineering, microfluidic equipment and gadgets, manufacturing techniques for complex fluid with peristaltic flow under the influence of slip limitations and magnetic force.

Association between the presence of CRISPR-Cas system genes and antibiotic resistance in Klebsiella pneumoniae isolated from patients admitted in Ahvaz teaching hospitals

BackgroundThis study aims to investigate the frequency of cas1 and cas3 and CRISPR1,2,3 genes in Klebsiella pneumoniae isolates, as well as their connection with antibiotic resistance.Materials and methods106 K. pneumoniae isolates were identified by biochemical assays and PCR. The susceptibility to antibiotics was determined by Kirby–Bauer disk diffusion method. Screening of ESBLs was undertaken by using double disk diffusion and standard disk diffusion methods. The E-test and mCIM techniques was used to confirm the disc diffusion-based carbapenem resistance profiles. CRISPR-Cas system genes were identified using PCR.ResultsESBL production was found in 19% of isolates. Carbapenemase production was found in 46% of the isolates. Furthermore, the bacteria were classified as multidrug (76%), extensively drug-resistant (4%), or pan-drug-resistant (2%). When CRISPR/Cas systems were present, antibiotic resistance was lower; conversely, when they were absent, resistance was higher.ConclusionsIf the CRISPR/Cas modules aren’t present, the bacteria can still acquire foreign DNA, including antibiotic resistance genes. K. pneumoniae isolates with a CRISPR-Cas system were less likely to carry antibiotic-resistance genes than those lacking this defense system.

A revised double diffusion Cattaneo–Christov bioconvective model for unsteady Williamson nanofluid due to Riga surface with additional nonlinear thermal sources

AbstractCurrent analysis presents the unsteady two‐dimensional flow of Williamson nanofluid with suspension of microorganisms due to stretched Riga surface with porous medium. The applications of external heat source/sink with non‐uniform relations are suggested. Furthermore, activation energy and nonlinear radiative effects are encountered. The extension in energy equation is subject to the implications of famous Cattaneo–Christov model. The problem is simplified with help of dimensionless quantities. The analytical simulations of formulated problem have been performed with help of built‐in bvp4c numerical scheme. The physical aspects of problem are presented for various flow parameters. It is claimed that velocity profile boosted due to modified Hartmann parameter while declining change in velocity profile is noted for Williamson fluid constant. The temperature field enhances for non‐uniform heat source constants. Current results convey applications in heat transfer enhancement, solar energy, extrusion processes, automobile industries, fertilizers, and so forth.

Bi-Stability Analysis Of Double Diffusive Convection In A Tilted Square Porous Cavity Filled With A Non-Newtonian Power-Law Fluids

Bi-Stability Analysis Of Double Diffusive Convection In A Tilted Square Porous Cavity Filled With A Non-Newtonian Power-Law Fluids

Magnetohydrodynamic double diffusion natural convection of power-law Non-Newtonian Nano-Encapsulated phase change materials in a trapezoidal enclosure

PurposeThe present numerical investigation examines the magnetohydrodynamic (MHD) double diffusion natural convection of power-law non-Newtonian nano-encapsulated phase change materials (NEPCMs) in a trapezoidal cavity.Design/methodology/approachThe governing Navier-Stokes, energy and concentration equations based on the Cartesian curvilinear coordinates are solved using the collocated grid arrangement’s finite volume method. The in-house FORTRAN code is validated with the different benchmark problems. The NEPCM nanoparticles consist of a core-shell structure with Phase Change Material (PCM) at the core. The enclosure, shaped as a trapezoidal hollow, features a warmed (Th) left wall and a cold (Tc) right wall. Various parameters are considered, including the power law index (0.6 ≤ n ≤ 1.4), Hartmann number (0 ≤ Ha ≤ 30), Rayleigh number (104 ≤ Ra ≤ 105) and fixed variables such as buoyancy ratio (Br = 0.8), Prandtl number (Pr = 6.2), Lewis number (Le = 5), fusion temperature (Θf = 0.5) and volume fraction (ϕ = 0.04).FindingsThe findings indicate a decrease in local Nusselt (Nu) and Sherwood (Sh) numbers with increasing Hartmann numbers (Ha). Additionally, for a shear-thinning fluid (n = 0.6) results in the maximum local Nu and Sh values. As the Rayleigh number (Ra) increases from 104 to 105, the structured vortex in the streamline pattern is disturbed. Furthermore, for different Ra values, an increase in n from 0.6 to 1.4 leads to a 67.43% to 76.88% decrease in average Nu and a 70% to 77% decrease in average Sh.Research limitations/implicationsThis research is for two-dimensioal laminar flow only.Practical implicationsPCMs represent a class of practical substances that behave as a function of temperature and have the innate ability to absorb, release and store heated energy in the form of hidden fusion enthalpy, or heat. They are valuable in these systems as they can store significant energy at a relatively constant temperature through their latent heat phase change.Originality/valueAs per the literature review and the authors’ understanding, an examination has never been conducted on MHD double diffusion natural convection of power-law non-Newtonian NEPCMs within a trapezoidal enclosure. The current work is innovative since it combines NEPCMs with the effect of magnetic field Double diffusion Natural Convection of power-law non-Newtonian NEPCMs in a Trapezoidal enclosure. This outcome can be used to improve thermal management in energy storage systems, increasing safety and effectiveness.

Scaling behavior of cation exchange membrane induced by Ca2+ during the electrodialysis for enriching lithium-containing solutions

Membrane fouling, particularly Ca2+-induced scaling on cation exchange membranes (CEM), hinders the application of electrodialysis in lithium extraction. This study investigated the fouling mechanisms of Ca2+ coexisting with Cl− and SO42− on sulfonated CEM, using CaCl2 and CaSO4 solution as the targeted foulants. The conductivity, pH, turbidity, particle size distribution, chemical composition and morphology of the membrane surface were monitored to verify the evolution of the bulk solution and the membrane during the Ca2+-induced fouling. Online detection of conductivity and pH revealed distinct trends in fouling solutions containing Ca2+-Cl- and Ca2+-SO42-. Noticeable changes in turbidity and particle distribution were observed in the concentrated chamber of the highly saturated Ca2+-SO42- solution, whereas the concentrated chamber of the Ca2+-Cl- solution showed turbidity and particle size distribution similar to the initial values. SEM showed that there are different morphologies of scaling crystals in the two types of solution. These fundamental differences are the root cause of the distinct fouling mechanisms between the Ca2+-Cl- solution and Ca2+-SO42- solution. To further investigate the fouling mechanisms, the electrochemical impedance spectroscopy (EIS) was employed to differentiate the impedance of the electric double layer and diffusion layer, providing insights into the characteristics of the CEM-solution interfaces fouled by different lithium-containing solutions. Additionally, adsorption experiments, quartz crystal microbalance with dissipation (QCM-D) and computational simulations (COMSOL, DFT) were conducted to provide detailed insights into the effects of fouling solutions on the properties of the desalted solution, the probability of crystal precipitation, and particularly the interaction between Ca2+ and the functional sites on the CEM. Finally, the Ca2+-induced scaling mechanism of CEM for enriching the lithium-containing solutions with and without SO42− was proposed, elucidating the synergistic effects of Ca2+-induced crystallization in the bulk solution and Ca2+ adsorption on the CEM surface. The research results could offer theoretical guidance for developing pollution control strategies.

Casson hybrid nanofluid flow over a Riga plate for drug delivery applications with double diffusion

Abstract Casson fluid-mediated hybrid nanofluids are more effective at transferring heat than traditional heat transfer fluids in terms of thermal conductivity. Heat exchangers, cooling systems and other thermal management systems are ideal for use with Casson fluids. Precise control of the flow and release of medication is necessary when using Casson fluids in drug delivery systems because of their unique rheological properties. Nanotechnology involves the creation of nanoparticles that are loaded with drugs and distributed in Casson fluid-based carriers for targeted delivery. In this study, to create a hybrid nanofluid, both single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) are dispersed in a Casson fluid with Fourier’s and Fick’s laws assumptions. The Casson fluid is suitable for various engineering and medical applications due to the enhancement of heat transfer and thermal conductivity by the carbon nanotubes. Our objective is to understand how SWCNTs and MWCNTs impact the flow field by studying the flow behavior of the Casson hybrid nanofluid when it is stretched against a Riga plate. The Darcy–Forchheimer model is also used to account for the impact of the porous medium near the stretching plate. Both linear and quadratic drag terms are taken into account in this model to accurately predict the flow behavior of the nanofluid. In addition, the homotopy analysis method is utilized to address the model problem. The outcomes are discussed and deliberated based on drug delivery applications. These findings shed valuable light on the flow characteristics of a Casson hybrid nanofluid comprising SWCNTs and MWCNTs. It is observed that the incorporation of carbon nanotubes makes the nanofluid a promising candidate for medical applications due to its improved heat transfer properties.

Chebyshev spectral Newton iterative analysis on unsteady oblique stagnation flow of Maxwell fluids over an oscillating-rotating disk with Cattaneo–Christov double diffusion

Oblique stagnation flow on a rotating disk is commonly observed in processes such as spinning coating and thin film deposition techniques. The investigation of the unsteady oblique stagnation point flow for Maxwell fluid over an oscillating-rotating disk embedded in a porous medium is meticulously conducted by employing the Darcy–Maxwell framework in conjunction with Cattaneo–Christov double diffusion model. A transformation of similarity is applied to reframe the governing equations into a system of non-dimensional coupled partial differential equations, whose numerical solutions are secured by the Chebyshev Spectral Newton Iterative Scheme. The outcomes underscore that an escalation in the Darcy parameter escalates the resistance within the porous medium, consequently leading to a reduction in velocity. Both the first-order slip and the second-order slip mitigate the fluid's interaction with the disk wall, leading to a retardation in flow velocity. Additionally, the presence of augmented thermal radiation parameters is observed to enhance heat transfer efficiency, resulting in a more homogenized temperature distribution. The two-dimensional and three-dimensional streamlines provide a precise depiction of the flow characteristics at the oblique stagnation point on the oscillating-rotating disk. These findings offer a theoretical foundation that can be instrumental for forthcoming research in analogous fields.

Data-driven wall modeling for LES involving non-equilibrium boundary layer effects

PurposeWall-modeled large eddy simulation (LES) is a practical tool for solving wall-bounded flows with less computational cost by avoiding the explicit resolution of the near-wall region. However, its use is limited in flows that have high non-equilibrium effects like separation or transition. This study aims to present a novel methodology of using high-fidelity data and machine learning (ML) techniques to capture these non-equilibrium effects.Design/methodology/approachA precursor to this methodology has already been tested in Radhakrishnan et al. (2021) for equilibrium flows using LES of channel flow data. In the current methodology, the high-fidelity data chosen for training includes direct numerical simulation of a double diffuser that has strong non-equilibrium flow regions, and LES of a channel flow. The ultimate purpose of the model is to distinguish between equilibrium and non-equilibrium regions, and to provide the appropriate wall shear stress. The ML system used for this study is gradient-boosted regression trees.FindingsThe authors show that the model can be trained to make accurate predictions for both equilibrium and non-equilibrium boundary layers. In example, the authors find that the model is very effective for corner flows and flows that involve relaminarization, while performing rather ineffectively at recirculation regions.Originality/valueData from relaminarization regions help the model to better understand such phenomenon and to provide an appropriate boundary condition based on that. This motivates the authors to continue the research in this direction by adding more non-equilibrium phenomena to the training data to capture recirculation as well.

Effects of double diffusion and soret effect on mhd braking of liquid metal packed between enclosed rotating cylindrical annulus

Effects of double diffusion and soret effect on mhd braking of liquid metal packed between enclosed rotating cylindrical annulus

Performance Improvement by Carbon-Dioxide Supercritical Fluid Treatment for 4H-SiC Vertical Double Diffusion MOSFETs

This study examines the impact of supercritical fluid treatment on 1200V 4H-SiC vertical double diffusion MOSFETs (VD-MOSFETs). When exposed to pure carbon dioxide or carbon dioxide mixed with nitrous oxide, there is a significant increase in the improvement ratio of drain current, which is contingent upon channel mobility but has no effect on threshold voltage. Conversely, the degradation of drain current caused by ammonia gas treatment is attributed to a reduction in channel mobility. Furthermore, the treatment with pure carbon dioxide or carbon dioxide mixed with nitrous oxide effectively passivates shallow defects, while the presence of hydrogen atoms in ammonia gas leads to an increase in shallow defects.

Impact of double diffusion on solid particle dispersion in rotated cylinders with nano-enhanced phase change materials

This study introduces an innovative approach that combines the Incompressible Smoothed Particle Hydrodynamics method with Artificial Neural Networks to examine the dispersion of solid particles within rotated circular cylinders filled with nano-enhanced phase change materials. This method addresses the limitations of traditional numerical techniques by improving accuracy in complex geometries and dynamic boundary conditions. The various parameters are examined, including the lengths of low sources in boundary walls Lb, dimensionless time τ, Hartmann number (Ha), Darcy number (Da), thermal radiation parameter (Rd), and Rayleigh number (Ra). The solid particles are initially situated at the center gate between the two circular cylinders, maintained at elevated temperature Th and concentration Ch. Due to the upward direction of convection flow, the solid particles are consistently dispersed into the top circular cylinder. The findings offer valuable insights into the system's behavior. The dispersion of solid particles within the NEPCM is influenced by both τ and Lb, showcasing minimal dispersion for τ≤0.1 and intensified dispersion for τ≥0.2, particularly augmented by larger Lb. The heat capacity ratio (Cr) exhibits a decrease with increasing Lb at multiple time points. A decrease in the Darcy number significantly slows down the dispersion of solid particles because of the substantial resistance posed by the porous medium. As the Rayleigh number increases, there is an enhanced dispersion of solid particles into the upper circular cylinder and heightened temperature distributions. Additionally, the average Nusselt number Nu¯ and Sherwood number Sh¯ decrease with the increase in Lb due to the expansion of low-temperature and concentration source. When the length Lb was increased from 0.25 to 1, Nu¯ and Sh¯ decreased by approximately 76% and 67%, respectively, underscoring the impact of geometric configuration on heat and mass transfer efficiency. The study highlights the effectiveness of the MLP model in predicting Nu¯ and Sh¯ values through graphical analysis, showing significant agreement with the target values. The results demonstrated notable improvements in managing particle dispersion and heat/mass transfer, emphasizing the potential of this integrated approach for applications in thermal management and energy optimization.

Effect of Electrolyte Composition over CO2 Reduction

The rapid utilization of fossil fuels escorted by an excess of CO2 emissions has led to global energy and environmental crisis. Therefore, the necessity for a clean, renewable and sustainable source of energy is a growing concern for the present and future society. In this regard, economically viable CO2 reduction would be a critical turnover in research, as it has the potential to fulfil a substantial need for clean energy. However, even though many efforts have been done in this field, there is still room for improvements concerning efficiency, material stability, and catalytic enhancement in regard of kinetics and selectivity. Herein, we provide the experimental proof for enhancement of the CO2 reduction efficiency and selectivity from the SEI (semiconductor-electrolyte interface) side through the use of carbonates, borates, sulphates and alkali cations as the electrolyte as well as an overview of the latest developments on Cu2O based PEC CO2 reduction for solar fuel production. Cu2O is a low-cost semiconductor and one of the most promising candidates for PEC CO2RR. However, its stability and performance is still unsatisfactory, thus the CO2 reduction products vary from one investigated system to another, such as: CH3OH, CO, HCOOH, CH3COOH, and CH3CH2OH. Moreover, the instability of Cu2O causes it, to be rarely used for the routine CO2 reduction reaction. In this paper, we use a very facile electrodeposition method, which offers a high level of reproducibility and the possibility of using a new electrode in each experiment, in order to focus our efforts on following the phenomena occurring in the double layer during the photocatalytic run. In this way, we were able to correlate the final CO2RR performance with a reorganization of the cations and anions near the photocatalyst surface. It is shown in the literature that factors such as: carbonate concentration, local pH, the presence of alkali metal cations, the geometry of the anionic group, CO2 solubility, conductivity, as well as pH changes along with the number of H+ in the electrolyte, play a significant role in regulating the partial CO2RR current. In this paper, we would like to shed new light on the influence of the electrolyte composition, cation-anion interaction and local reaction environment around the catalyst on the performance of CO2RR. We found out that the specific interaction between the alkali cation and the anionic group of particular geometry contributes to the formation of a kind of a “rigid layer” within the double diffusion, close to the photocatalyst surface layer, which accounts more for an apparent CO2RR current than the decrease in the finite Warburg element, which is a central key parameter for the diffusion coefficient values. The effectiveness of the strength of the cation-anion interaction in the formation of the “rigid layer” around the photocatalyst surface is found to increase the PEC CO2RR performance. Elucidating this mechanism provides useful information for creating further experimental design and the new pathways for addressing highly efficient PEC CO2RR systems. The authors have noticed a significant knowledge gap in the existing literature, as no prior publications have delved into the concurrent and combined impact of both cations and anions on PEC CO2RR. In this pioneering publication, we present the inaugural investigation of this this intricate phenomenon.

A multiple applications study of motile microorganisms past a vertical surface with double‐diffusive binary base fluid

AbstractThis study investigates the various uses of density of motile microorganisms in the context of the flow of a binary base fluid with double diffusion past a vertical surface. The research aims to comprehend the interactions between motile microorganisms and the fluid dynamics, as well as the heat and mass transport mechanisms in this system. The analysis involves mathematically constructing the governing equations, transforming them into dimensionless nonlinear ordinary differential equations using similarity transformations, and numerically solving them using the MATLAB bvp4c solver. An analysis of the influence of several parameters on the profiles of velocity, temperature, concentration, nanoparticle concentration, and density of motile microorganisms is conducted using graphical representation. The findings demonstrate that boosting the thermophoresis parameter intensifies the temperature profile. In addition, an increase in the nanofluid Schmidt number results in a larger concentration of nanoparticles, whereas a higher bioconvection Lewis number reduces the density of the motile microorganism profile. These findings may find use in biomedical engineering as well as industrial processes that include enhancing the efficiency of mass transfer and bioconvection. Numeric simulation prophesies 99.9% for both shear stress and heat transfer rate intensification for Prandtl values are noticed.

Numerical evaluation for the peristaltic flow in the proximity of double-diffusive convection of non-Newtonian nanofluid under the MHD

This article mainly studies the 2-D propagation of a non-compressible Eyring-Powell nanofluid flow through a stretched wedge under the Magneto-hydrodynamic effect. Equations for temperature, concentration, double-diffusive convection and momentum are taken into consideration. Since solving the dimensionless equations associated with our study is an uphill task, we utilize the MATLAB bvp4c solver to illustrate the graphical performance of different parameters. This manuscript may be significant in the projects in the field of industry and medicine. The manuscript's noteworthy features include the magnetic field, heat source-sink parameter, double diffusivity, and solar radiation process. The main finding is that the local fluid parameter k1 and magnetic field parameter M decelerate the velocity of nanofluid. Because different nanoparticles have different effects on fluids, the fluid's temperature exhibits multiple behaviors, therefore by escalating the Prandtl number initially, it increases and then decelerates due to the presence of nanoparticles. The concentration of fluid declines as the Schmidt number rises. The double diffusivity of Eyring-Powell nanofluid improves with magnification in the fluid's Schmidt number Sc and Prandtl number Pr.

Image reconstruction from speckle patterns on double diffusers condition by deep learning

Reconstructing images from speckle patterns using deep learning methods is emerging as an effective alternative to traditional approaches. To overcome the potential multiple diffuser distortions occurring between the emission and the detection of the optical path, we establish a 4-f imaging system incorporating dual diffusers, one positioned in front of the image plane and the other after the object plane, to capture plenty of scattered object images. To effectively reconstruct from the experimentally acquired speckle patterns, we add the Triple Attention Module into the UNeXt convolutional network (TAM-UNeXt) and concurrently preprocess the autocorrelation spectrum of the patterns inspired by the angular memory effect theory. We compare the recovery results of the TAM-UNeXt under various conditions, including different grit sizes, numbers, and positions of the diffusers, as well as several optical lens setups, to verify its adaptability under diverse double diffuser conditions.

Double diffusion convection of Maxwell–Cattaneo fluids in a vertical slot

Abstract The convection stability of Maxwell–Cattaneo fluids in a vertical double-diffusive layer is investigated. Maxwell–Cattaneo fluids mean that the response of the heat flux with respect to the temperature gradient satisfies a relaxation time law rather than the classical Fourier one. The Chebyshev collocation method is used to resolve the linearized forms of perturbation equations, leading to the formulation of stability eigenvalue problem. By numerically solving the eigenvalue problem, the neutral stability curves in the a–Gr plane for the different values of solute Rayleigh number RaS are obtained. Results show that increasing the double diffusion effect and Louis number Le can suppress the convective instability. Furthermore, compared with Fourier fluid, the Maxwell–Cattaneo fluids in a vertical slot cause an oscillation on the neutral stability curve. The appearance of Maxwell–Cattaneo effect enhances the convection instability. Meanwhile, it is interesting to find that the Maxwell–Cattaneo effect for convective instability becomes stronger as the Prandtl number rises. That means Prandtl number (Pr) also has a significant effect on convective instability. Moreover, the occurrence of two minima on the neutral curve can be found when Pr reaches 12.