Effects Of Heat Transport Research Articles

Transported Entropy of Ions and Peltier Coefficients in 8YSZ and 10Sc1CeSZ Electrolytes for Solid Oxide Cells.

In this study, the transported entropy of ions for 8YSZ and 10Sc1CeSZ electrolytes was experimentally determined to enable precise modeling of heat transport in solid oxide cells (SOCs). The Peltier coefficient, crucial for thermal management, was directly calculated, highlighting reversible heat transport effects in the cell. While data for 8YSZ are available in the literature, providing a basis for comparison, the results for 10Sc1CeSZ show slightly smaller Seebeck coefficients but higher transported ion entropies. Specifically, at 700°C and an oxygen partial pressure of pO2=0.21 bar, values of SO2-*=52±10 J/K·F for 10Sc1CeSZ and SO2-*=48±9 J/K·F for 8YSZ were obtained. The transported entropy was also validated through theoretical calculations and showed minimal deviations when comparing different cell operation modes (O2||O2-||O2 and H2, H2O||O2-||O2). The influence of the transported entropy of the ions on the total heat generation and the partial heat generation at the electrodes is shown. The temperature has the greatest influence on heat generation, whereby the ion entropy also plays a role. Finally, the Peltier coefficients of 8YSZ for all homogeneous phases agree with the literature values.

How advection affects the surface energy balance and its closure at an irrigated alfalfa field

Orbiting around the non-closure problem in eddy covariance, a new generation of high-resolution thermal imagery has revealed that advection may be more common than previously expected. To investigate this, we conducted an extensive study over an irrigated alfalfa field that experienced heat and moisture advection. Over the course of five analysis periods (37 days total), multiple tower arrays and profile measurements were deployed to measure the horizontal advection and vertical heat flux divergence. Latent heat flux (λE) measured at the anchor tower showed an enhancement (i.e., increase) due to both local and non-local processes. Locally, as a result of the upwind λE, advection humidified the atmosphere and increased stomatal opening, enhancing the downwind λE. Simultaneously, with lowered atmospheric demand, λE was suppressed downwind. Our results suggest that stomatal regulation played a dominant role in the enhancement, but not by itself. Spectral analysis revealed that low frequency (i.e., large) eddies contributed high heat and moisture via advection. In combination with thermal remote sensing observations from ECOSTRESS and Landsat 8/9, we found that these large eddies were generated over the upwind surface, and they were independent of the local boundary layer conditions. Consequently, spatiotemporal heterogeneity in land-surface conditions induced large eddies, further enhancing λE through non-local transport of heat and moisture. Lastly, by conditionally including the advective fluxes, the energy balance closure improved from 89 % to 97 % (r2 = 0.97, p < 0.001) over the five analysis periods. Results from this improved energy balance closure suggest an alternative approach for developing validation datasets for remote sensing evapotranspiration (ET) models rather than forcing closure with Bowen-ratio. Furthermore, our findings provide insights for algorithms that may improve remote sensing ET products that treat pixels as isolated columns rather than also considering the lateral effects of heat and moisture transport.

Implementing the predictor-corrector approach to examine the thermo-solutal convection for buongiorno eyring-powell nanofluid model with squeezed microcantilivier surface

The Buongiorno nanofluid model serves as a foundational model for theoretical and experimental research in the field of nanofluids, and this model can be applied to various engineering problems, including heat exchangers, biomedical applications, solar collectors, nuclear reactors, and different cooling systems in the automotive and electronics industries. The use of nanofluids in the Eyring-Powell fluid over a squeezed sensing surfaces is a vital area of research for the design and improvement of microfluidic devices and sensors, which find widespread usage in industrial and medical applications. The main purpose of this work is to note the augmentation in thermal conductivity by using the Buongiorno nanofluid model along with the natural convective flow of non-Newtonian Eyring-Powell fluid that is moving on the squeezed sensory surface along with slip velocity. The viscosity of a fluid is assumed to be dependent on temperature. The Cattaneo-Christov heat and mass flux and chemical reaction are assumed to determine the combined effect of heat and mass transport. The governing model of equations is in the form of dimensional partial differential equations, and we have to convert these equations into ordinary differential equations; therefore, a set of similarity transformations is adopted for making the equations into dimensionless form. The numerical results were obtained by adopting the predictor and corrector multistep method, namely the ‘Adams-Bashforth’ technique, in Matlab software. The use of natural convective flow enhances the velocity region. The velocity slip parameter increases the velocity of the fluid, whereas the viscosity parameter drops the velocity profile. The thermophoresis and Brownian motion parameters are the sources of the increment in the temperature region. The thermal relaxation and solutal relaxation parameters are the sources of decline in the temperature region. The squeezing parameter is the source of reduction in the skin friction, whereas the result indicates that the fluid parameter, Grashof number, and viscosity coefficients increase the skin friction.

Significance of Rosseland’s radiative heat transfer and dissipative heat on MHD viscous flow over a slandering sheet in the presence of Darcy-Forchheimer and Lorentz forces

The main emphasis of this research is to investigate computationally an innovative viscous, time-independent, and Darcy-Forchheimer flow of an electrically based incompressible nanofluid on a slandering stretched surface. The thermal conductivity and viscosity of this flow will be discussed. Incorporating an outer heat source into the thermal transfer process enhances the effect of dissipative heat and thermal radiation. When chemical processes are included, the effects of heat and solvent transport are influenced by the use of convective constraints at boundary. The flow characteristics are governed by the mathematical form which is further transferred to ordinary differential equations (ODEs) via appropriate assumptions regarding similarity variables and stream functions. The analytical technique for such highly nonlinear equations sometimes doesn't work effectively due to the strong nonlinearity. As a result, these transformed ODEs are solved numerically by means of bvp4c approach. Graphs depict the impacts of different substantial factors on velocity, temperature, and solutal concentration distributions. Numerical computations of physical quantities including magnetic parameters, inertial coefficient, permeable coefficient, thickness factor, heat transfer Biot number, Radiation parameter, Prandtl number, Eckert number, mass transfer Biot number, Schmidt number, heat source factor, and chemical reaction are evaluated and tabulated. The current findings are compared to previously known results, and they are in great agreement. The main outcomes of the study are thoroughly explained in the results and discussion section. Heat transfer Biot number raises the energy distribution and mass transfer Biot number strengthened the concentration profile while wall thickness quantity reduces the temperature and concentration of fluid as well. The enhanced variable viscosity is augmented by the longitudinal velocity profile and the rate of shear stress.

Robust Polar Amplification in Ice-Free Climates Relies on Ocean Heat Transport and Cloud Radiative Effects

Abstract A fundamental divide exists between previous studies that conclude that polar amplification does not occur without sea ice and studies that find that polar amplification is an inherent feature of the atmosphere independent of sea ice. We hypothesize that a representation of climatological ocean heat transport is key for simulating polar amplification in ice-free climates. To investigate this, we run a suite of targeted experiments in the slab ocean aquaplanet configuration of CESM2-CAM6 with different profiles of prescribed ocean heat transport, which are invariant under CO2 quadrupling. In simulations without climatological ocean heat transport, polar amplification does not occur. In contrast, in simulations with climatological ocean heat transport, robust polar amplification occurs in all seasons. What is causing this dependence of polar amplification on ocean heat transport? Energy-balance model theory is incapable of explaining our results and in fact would predict that introducing ocean heat transport leads to less polar amplification. We instead demonstrate that shortwave cloud radiative feedbacks can explain the divergent polar climate responses simulated by CESM2-CAM6. Targeted cloud locking experiments in the zero ocean heat transport simulations are able to reproduce the polar amplification of the climatological ocean heat transport simulations, solely by prescribing high-latitude cloud radiative feedbacks. We conclude that polar amplification in ice-free climates is underpinned by ocean–atmosphere coupling, through a less negative high latitude shortwave cloud radiative feedback that facilitates enhanced polar warming. In addition to reconciling previous disparities, these results have important implications for interpreting past equable climates and climate projections under high-emissions scenarios. Significance Statement Polar amplification is a robust feature of climate change in the modern-day climate. However, previous climate modeling studies fundamentally do not agree on whether polar amplification occurs in ice-free climates. In this study, we find in a state-of-the-art climate model that, if ocean heat transport is neglected, the response to an increase in CO2 is not polar amplified, whereas robust polar amplification occurs if ocean heat transport is included. Using targeted model experiments, we diagnose cloud radiative effects as the driver of this divergent behavior. We conclude that polar amplification is a robust feature of the atmosphere–ocean system. Our results have important implications for interpreting past warm climates and future projections under high-emissions scenarios.

Empirical test of the Kelvin relation in thermoelectric nanostructures

Thermoelectric (TE) nanostructures with dimensions of ∼100 nm can show substantially better TE properties compared to the same material in the bulk form due to charge and heat transport effects specific to the nanometer scale. However, TE physics in nanostructures is still described using the Kelvin relation (KR) Π = αT, where Π is the Peltier coefficient, α the thermopower, and T the absolute temperature, even though derivation of the KR uses a local equilibrium assumption (LEA) applicable to macroscopic systems. It is unclear whether nanostructures with nanostructures with dimensions on the order of an inelastic mean free path satisfy a LEA under any nonzero temperature gradient. Here, we present an experimental test of the KR on a TE system consisting of doped silicon-based nanostructures with dimensions comparable to the phonon–phonon and electron–phonon mean-free-paths. Such nanostructures are small enough that true local thermodynamic equilibrium may not exist when a thermal gradient is applied. The KR is tested by measuring the ratio Π/α under various applied temperature differences and comparing it to the average T. Results show relative deviations from the KR of |(Π/α)/T − 1| ≤ 2.2%, within measurement uncertainty. This suggests that a complete local equilibrium among all degrees of freedom may be unnecessary for the KR to be valid but could be replaced by a weaker condition of local equilibrium among only charge carriers.

Entropy generation in a partially heated hybrid nanofluid saturated wavy porous cavity

PurposeA porous cavity flow field generates entropy owing to energy and momentum exchange within the fluid and at solid barriers. The heat transport and viscosity effects on fluid and solid walls irreversibly generate entropy. This numerical study aims to investigate convective heat transfer together with entropy generation in a partially heated wavy porous cavity filled with a hybrid nanofluid.Design/methodology/approachThe governing equations are nondimensionalized and the domain is transformed into a unit square. A second-order finite difference method is used to have numerical solutions to nondimensional unknowns such as stream function and temperature. This numerical computation is conducted to explore a wide range of regulating parameters, e.g. hybrid nano-particle volume fraction (σ = 0.1%, 0.33%, 0.75%, 1%, 2%), Rayleigh–Darcy number (Ra = 10, 102, 103), dimensionless length of the heat source (ϵ = 0.25, 0.50,1.0) and amplitude of the wave (a = 0.05, 0.10, 0.15) for a number of undulations (N = 1, 3) per unit length.FindingsA thorough analysis is conducted to analyze the effect of multiple factors such as thermal convective forces, heat source, surface corrugation factors, nanofluid volume fraction and other parameters on entropy generation. The flow and temperature fields are studied through streamlines and isotherms. The average Bejan number suggested that entropy generation is entirely dominated by irreversibility due to heat transport at Ra = 10, and the irreversibility due to the viscosity effect is severe at Ra = 103, but the increment in s augments irreversibility due to the viscosity effect over the heat transport at Ra = 102.Originality/valueTo the best of the authors’ knowledge, this numerical study, for the first time, analyzes the influence of surface corrugation on the entropy generation related to the cooling of a partial heat source by the convection of a hybrid nanofluid.

A meridional dipole mode in the Indian Ocean subsurface ocean heat content and its multidecadal variability

The dominant mode of the Indian Ocean variability can be impacted by changes in the background state (multidecadal timescale) of the subsurface heat content. The multidecadal variability of subsurface ocean heat content (sub-OHC) in the Indian Ocean is examined using four reanalysis products from 1958 to 2017. The analysis reveals a meridional basin-wide dipole mode in the subsurface OHC until the late 1980s, followed by the mode embedded in the uniform basin-wide patterns. These patterns are also observed in the trends of thermocline and sea surface height. The observed patterns in the Indian Ocean are explained by two distinct mechanisms. Firstly, the multidecadal variability of dipole patterns over the Indian Ocean is influenced by local wind forcing. Wind stress trends and Ekman pumping velocity trends favor downwelling (upwelling) in the off-equatorial southern Indian Ocean region, leading to thermocline depth deepening (shallowing) during 1958–1975 and 1976–1987, respectively. Secondly, the combined effect of heat transport from the western Pacific through Indonesian Through Flow and local wind forcing accounts for the basin-wide cooling and warming trends observed during 1988–2000, and 2001–2014, respectively.

MHD nanofluid flow with energy transfer over a porous stretching surface by using a second-grade fluid model

The main attention of this research is to examine the nature of the flow behavior of nanofluids and energy transfers past an expanding sheet with second-grade fluid model. The system is also situated in an absorbent area, which affects the effects of heat and mass transport and chemical reaction. The numerical calculations and visualization for various flow parameters are performed using a finite difference code that is developed in the built-in bvp4c solver scheme of MATLAB. This involves adopting a set of new variables to change the character of the governing equations of this study. To the best of the authors’ knowledge, many authors have contributed to this field, but they do not take into account the above fluid model associated with the energy transfers with the influences of Brownian motion, thermophoresis effect, and chemical reaction parameters, etc., in their study. Major findings of this study is to achieve a higher amount of thermal transference using the physical parameters, such as magnetic, visco-elastic, thermophoresis, and Brownian motion parameters, etc. Also, using smaller values of the magnetic parameter can be an effective way to minimize the impact of drag force of the fluid at the surface. The considering fluid model has multifarious industrial applications, such as food and cosmetic industry and pharmaceutical and biomedical industry, etc., due to its versatile rheological characteristics.

Understanding of Co-boiling between Organic Contaminants and Water during Thermal Remediation: Effects of Nonequilibrium Heat and Mass Transport.

In situ thermal desorption (ISTD) provides an efficient solution to remediation of soil and groundwater contaminated with nonaqueous phase liquids (NAPLs). Establishing a relationship between the subsurface temperature rise and NAPL removal is significant to reduce energy consumption of ISTD. However, the co-boiling phenomenon between NAPL and water poses a great challenge in developing this relationship due to the nonequilibrium heat and mass transport effects. We performed a systematic experimental investigation into the local temperature rise patterns at different distances from a NAPL pool and under different degrees of superheat by selecting four representative NAPLs (i.e., trichloroethylene, tetrachlorethylene, n-hexane, and n-octane) according to their density and boiling point relative to water. The patterns of temperature rise indicated that the underground temperature field can be divided into three zones: the zone of local thermal equilibrium, the nonequilibrium zone affected by co-boiling, and the zone unaffected by co-boiling. We developed a pattern-recognition-based approach, which considers the effects of local heat and mass transport to establish a qualitative correlation between the temperature rise and NAPL removal. Our results give deeper insights into the understanding of subsurface temperatures in ISTD practice, which can serve as the guideline for more accurate and sustainable remediation.

Exploring the dynamics of active swimmers microorganisms with electromagnetically conducting stretching through endothermic heat generation/assimilation flow: Observational and computational study

Enhancements brought about by motile gyrotactic microorganisms encompass improved mixing, efficient oxygen and nutrient transfer, environmental sensing, and reactions, as well as potential applications in bioremediation, contributing to the advancement of knowledge in fluid dynamics and biological locomotion. These microorganisms find utility in various fields such as biotechnology, environmental engineering, and fluid dynamics research, among others, playing a pivotal role in numerous ecological processes. The present study places its focus on the investigation of the effects associated with mass and heat transport in a fluid flow scenario featuring the presence of a heat source or sink. Specifically, the study aims to examine the impact of nanoparticles on Powell-Eyring fluid flow in the presence of a magnetic field (MHD) across a stretched sheet, taking into account factors such as activation energy, heat sources, and thermal radiation. Furthermore, the study explores the influence of motile gyrotactic microorganisms on various parameters. Recognizing the dearth of research in the realm of polymer extrusion processes, this study strives to bridge this research gap. Its primary objective is to develop a mathematical formulation employing a boundary layer approach, which encompasses the consideration of the interrelated effects of mass and heat transport in Eyring-Powell fluid flow across a stretched sheet in the presence of thermal radiation and chemical reactions from figure it shows that temperature profile rises as result of radiation parameter's increasing values (0.1<Rd<0.4). The impact of Lb is also showed with the help of graph. Greater diffusive mixing is implied by higher Lb for (0.1<Lb<0.4), which tends to distribute the microbes more equally throughout the fluid. This research study serves as an inspiration for the innovation of endogenous heat generation/consumption within the flow of motile organisms exhibiting gyro-taxis in the presence of magnetic flux density on a stretching sheet. To address the complexity of the problem, the renowned BVP4C package, a computational software tool in MATLAB, is utilized for solving a set of highly intricate and nonlinear coupled differential equations. The nonlinear nature of these equations poses significant challenges, necessitating the application of specialized numerical methods to ensure accurate and efficient solutions.

Influence of filler topology on the thermal transport of composite materials based on similarity principle modeling: A cross-scale simulation study

The thermal conductivity parameter of the materials is a fundamental parameter for thermal design and study of heat transfer processes. In our study, we combined the homogenization theory based on the finite element with the thermal conductivity order-of-magnitude analysis and similarity principle, to construct structural models of fibers, spheres, ellipsoids, sheets, and interfaces, and establish the topology of intermingling and encapsulation of different structures. Combined thermal conductivity calculations of mesoscopic composites and microscopic interface models using finite element and molecular dynamics methods. The anisotropy model of thermal conductivity was established by coordinate transformation. Based on the numerical verification of the reliability of the method, the mechanisms of the influence on the thermal transport of composites were analyzed for parameters such as volume fraction of different structural fillers, structural shape, thermal conductivity ratio, thickness of highly thermally conductive coatings, and spatial orientation distribution. The results showed that the effective thermal conductivity (ETC) of the continuous structural reinforced composite was mainly influenced by the volume fraction of the filler; the modulation of ETC with ellipsoidal particle structure form and distribution mode was comparable to the effect of changing the volume fraction modulation; the mutual fusion between ellipsoids randomly distributed in the plane could effectively enhance the heat transport effect of the composite, and as the volume fraction increased to more than 3%, the heat transport gain from mutual fusion was more obvious; spraying high thermally conductive copper coating on ellipsoidal particles could significantly enhance the ETC of the composites. The present work could provide reference for composites in terms of structural improvement and thermal performance enhancement.

The ignition of fine iron particles in the Knudsen transition regime

A theoretical model is considered to predict the minimum ambient gas temperature at which fine iron particles can undergo thermal runaway–the ignition temperature. The model accounts for Knudsen transition transport effects, which become significant when the particle size is comparable to, or smaller than, the molecular mean free path of the surrounding gas. Two kinetic models for the high-temperature solid-phase oxidation of iron are analyzed. The first model (parabolic kinetics) considers the inhibiting effect of the iron oxide layers at the particle surface on the kinetic rate of oxidation, and a kinetic rate independent of the gaseous oxidizer concentration. The ignition temperature is solved as a function of particle size and initial oxide layer thickness with an unsteady analysis considering the growth of the oxide layers. In the free-molecular limit (small particles), the thermal insulating effect of transition heat transport can lead to a decrease of ignition temperature with decreasing particle size; however, the presence of the oxide layer slows the reaction kinetics, and its increasing proportion in the small-particle limit can lead to an increase of ignition temperature with decreasing particle size. This effect is observed for sufficiently large initial oxide layer thicknesses. The continuum transport model is shown to predict the ignition temperature of iron particles exceeding an initial diameter of 30 µm to a difference of 3% or less (30 K or less) when compared to the prediction of the transition transport model. The second kinetic model (first-order kinetics) considers a porous, non-hindering oxide layer, and a linear dependence of the kinetic rate of oxidation on the gaseous oxidizer concentration. The ignition temperature is resolved as a function of particle size with the transition and continuum transport models, and the differences between the ignition characteristics predicted by the two kinetic models are identified and discussed.

Biomedical and engineering aspects of nonlinear radiative peristaltic transport in chemically reactive blood flow of Ellis nanofluid in an asymmetric channel with activation energy

• Here peristaltic transport phenomenon is examined via asymmetric channel. • Ellis fluid model is utilized for the flow behavior. • Streamlines is presented. • Nonlinear radiative heat flux is used in energy expression. In the recent couple of decades, a momentous curiosity has been established in reviewing a peristaltic transport due to its noteworthy utilizations in biomathematics, biomedical engineering and biosciences. Peristaltic phenomenon is a significant mechanism of peristaltic pumps and physiological phenomenon. With the development of clinical and medical sciences, it has been demonstrated that the physiological materials don't act like Newtonian materials. Thus, in order to comprehend the salient characteristics of physiological materials (fluids) during peristalsis, the choice of suitable fluid model is important. In the present research letter, effects of heat and mass transport is addressed in flow of Ellis fluid nanofluid via asymmetric channel. The nonlinear radiative effects are imposed to studying the heat transfer transport. Features of activation energy is considered in the modeling of concentration equation. The governing expressions of proposed model is followed under the assumptions of small Reynolds number hypothesis and long wavelength. To investigate the salient characteristics of flow features and heat and mass transport, analytical solutions have been obtained for the velocity, temperature, pressure gradient and concentration. The obtained outcomes is presented through graphically and discussed in details physically. Furthermore, streamlines is sketched for different parameters. The current theoretical attempt discloses various motivating performance that warrant further investigation on different Newtonian as well as non-Newtonian materials. It is observed from the current flow analysis that the impact of slip factor highlights reverse behavior on the channel wall whereas the impact of Prandtl and Schmidt number respectively on the temperature and concentration equations have a decreasing and increasing trend.

An axisymmetric bioheat transfer analysis through a unified model

AbstractA unified model is developed for the analysis of heat transfer (radiation and non‐Fourier conduction) in an axisymmetric participating medium. The proposed model includes three different variants of hyperbolic–parabolic heat conduction models, that is, the single phase lag model, dual phase lag model, and the Fourier (no phase lag) model. The radiating‐conducting medium is radiatively absorbing, emitting, and isotropically scattering. Significance of all the above mentioned models on the heat transfer characteristics is investigated in a two‐dimensional axisymmetric geometry. The equation of transfer and the coupled non‐Fourier conduction‐radiation equation are solved via finite volume method. A fully implicit scheme is used to resolve the transient terms in the energy equation. For spatial resolution of radiation information, the STEP scheme is applied. Tri‐diagonal‐matrix‐algorithm is used to solve the resulting set of linear discrete equations. Effects of two important influencing parameters: the scattering albedo and the radiation‐ conduction parameter are studied on the temporal evolution of temperature field in the radiatively participating medium. The non‐Fourier effect of heat transport captured well with the proposed unified model. A good agreement can be found between the proposed model predictions and those available in the literature. It is also found that when the phase lag of the temperature gradient and the heat flux are the same, it reduces to conventional Fourier conduction‐radiation and the wave behavior diminishes. However, the reduction to this Fourier model fails in the presence of constant blood perfusion and metabolic heat generation.

Numerical Study on the Effects of Water and Heat Transport on Two-Phase Flow in a Polymer Electrolyte Membrane Fuel Cell

A one-dimensional transient non-isothermal model was developed to study the two-phase flow phenomenon in a polymer electrolyte membrane fuel cell. The model focused on the phase change between vapor and liquid water, and the transport of oxygen, hydrogen, water, and heat. The cell was discretized into 39 control volumes, and the finite volume method and the iteration method were used to solve the transport equations. The variations in the state parameters of the model during fuel cell operations were analyzed. The results showed that, when the inlet gas humidity was high, the vapor tended to condense in gas diffusion layer regions close to the gas channel. As temperatures in these regions were low, the vapor was more likely to condense. Liquid water appeared latest in the middle of the anode gas diffusion layer, because the vapor concentration in this area is always lower than its saturated value. A higher operating temperature in a cell is beneficial to prevent flooding at the cathode.

Supratough and stretchable hydrogels with time-space controllability for athletic rehabilitation

There is a higher risk of injury for athletes when the intensive competition occurs. Minimally invasive surgery is still the first choice for athletes because of its small wound surface and fast recovery. In addition, knowing whether athletes recover in real time at the first time is beneficial for the athletes to return to the competition as soon as possible and maintain their peak performance. We developed a medical hydrogel to meet the dual needs of minimally invasive therapy and wearable testing. A novel ε-PL/PVP/MXene (εPM) hydrogel with spatio-temporal control and in situ enhancement was prepared by the concept of microchemical reaction cavity. MXene was introduced as the microchemical reaction center, and the dual effects of heat transport and microcatalysis were utilized to make the gel network uniform and moldability after injection in vivo, so as to realize the filling and treatment of irregular wounds. The hydrogel tissue is not only adhesive, self-healing and soft, but also super tough, keeping its shape stable under repeated stretches, intense hammering, continuous trampling, and even the extremely catastrophic impact of being run over 50 times by a car. At the same time, the hydrogel has excellent ionic conductivity (4.12 S/m) and sensing ability, which can record athletes' movement characteristics in real time and transmit them to doctors through wireless Bluetooth, so as to make accurate judgment on the recovery of health. This is the first exploration of the combination of hydrogel in the field of minimally invasive therapy and wearable devices, which opens up a new avenue for efficient minimally invasive therapy and accurate rehabilitation monitoring.

Mitigation of the ablative Rayleigh–Taylor instability by nonlocal electron heat transport

The effects of electron nonlocal heat transport (NLHT) on the two-dimensional single-mode ablative Rayleigh–Taylor instability (ARTI) up to the highly nonlinear phase are reported for the first time through numerical simulations with a multigroup diffusion model. It is found that as well as its role in the linear stabilization of ARTI growth, NLHT can also mitigate ARTI bubble nonlinear growth after the first saturation to the classical terminal velocity, compared with what is predicted by the local Spitzer–Härm model. The key factor affecting the reduction in the linear growth rate is the enhancement of the ablation velocity Va by preheating. It is found that NLHT mitigates nonlinear bubble growth through a mechanism involving reduction of vorticity generation. NLHT enhances ablation near the spike tip and slows down the spike, leading to weaker vortex generation as the pump of bubble reacceleration in the nonlinear stage. NLHT more effectively reduces the nonlinear growth of shorter-wavelength ARTI modes seeded by the laser imprinting phase in direct-drive laser fusion.

Koo and Kleinstreuer–Li correlation and modified Buongiorno model on unsteady radiative non-Newtonian fluid flow

This research paper investigates the heat and mass transport characteristics in an unsteady flow of Maxwell nanofluid (NF). While examining heat transfer properties, thermal radiation is taken into account. Further, copper oxide with water-based NF is considered. The mass transfer and effective thermal conductivity of nanofluid flow are scrutinized by Koo and Kleinstreuer–Li (KKL) NF model. Through apt transformations, relevant flow expressions are converted to ordinary differential equations (ODEs). The numerical approach Runge–Kutta–fourth–fifth Fehlberg’s order process (RKF-45) algorithm with shooting technique is utilized to solve the generated ODEs. Results reveal that, the rise in values of unsteadiness parameter has a positive impact on both concentration and thermal profiles. The Deborah number has constructive impact on heat transport and reverse influence on velocity field. The improved heat transport is seen for augmented values of radiation and heat source/sink parameters. The Brownian motion parameter has positive influence on heat transport and reverse effect on mass transport.

Effects of magma-generation and migration on the expansion and contraction history of the Moon

Geological and geodetic observations of the Moon from spacecraft revealed that it expanded by a few km for the first several hundred million years and then contracted later. The period when the planet expanded most coincides with that when the mare volcanism of the Moon was active. Given the high initial temperature of the deep mantle inferred from the giant impact and mantle overturn hypotheses of the Moon, the observed early expansion is difficult to account for by thermal expansion only. To understand the observed radial change of the Moon, we numerically calculated the thermal evolution of a one-dimensional spherically symmetric mantle caused by transport of heat, mass, and incompatible heat-producing elements (HPEs) by migration of magma that is generated by internal heating. The mantle is assumed to be enriched in HPEs at its base in the initial condition. The calculated mantle expands for the first several hundred million years by melting of the deep mantle and upward migration of the generated magma to the uppermost mantle; the top of the partially molten region rises to the depth level of around 300 km, which is shallow enough to generate mare basalts of the Moon. The migrating magma, however, extracts HPEs from the deep interior, and the planet then contracts gradually by cooling and solidification of the partially molten mantle. We obtained a thermal history model that is consistent with the observed history of radial change of the Moon when the initial mid-mantle temperature T_{{text{M}}} approx 1600 ,{text{K}} and the initial ratio of the concentration of HPEs in the crust to that of the mantle F_{{{text{crst}}}}^{*} le 12. This model suggests that melting of the deep mantle and upward migration of the generated magma strongly affect the thermal history of the Moon. The model we developed here is a good starting point for constructing more realistic models of the thermal history of the Moon where the effects of heat and mass transport by mantle convection are also considered.Graphical