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A dendrite-free and ultra-stable potassium metal composite anode has realized by infusing metallic potassium into a 3D potassiophilic α-MoC modified carbon cloth. Both the density ...functional theory (DFT) calculations and COMSOL Multiphysics demonstrate that the potassiophilic 3D host not only can facilitate fast molten potassium wetting and reduce nucleation overpotential but also homogenize the distribution of current density and inhibit potassium dendrite growth.
•Dendrite-free K metal anode has realized by potassiophilic α-MoC modified host.•3D potassiophilic host reduces nucleation overpotential and inhibits dendrite.•3D potassiophilic host homogenizes the distribution of current density.•DFT and COMSOL demonstrate the effectiveness of 3D potassiophilic host.
Potassium metal anodes are desirable for the advantages of low price, high abundance, and similar standard redox potential with metallic lithium. However, dendritic growth and large volume changes impede its practical application. Herein, a dendrite-free and stable potassium metal composite anode has realized by infusing metallic potassium into an α-MoC modified carbon cloth (α-MoC@CC). The prepared α-MoC@CC as a 3D host exhibits an intrinsic potassiophilicity based on experimental investigations and density functional theory (DFT) calculations, which not only facilitates fast molten potassium wetting but also reduces nucleation overpotential. In addition, the current density distribution of the composite anode carried out by COMSOL Multiphysics reveals that the 3D host can effectively reduce current density and inhibit dendrite growth. Consequently, the K@α-MoC@CC composite anode displays stable plating/stripping profiles for more than 2000 h with low polarization in symmetric batteries. As a practical device application, the K@α-MoC@CC composite anode demonstrates superior suitability when paired with Prussian blue cathode in a full battery. Significantly, this work represents an effective pathway to regulate potassium metal anode towards practical applications.
Numerical simulations of the deformation, aggregation, and migration processes of emulsified oil droplets under the influence of a multiphase field were conducted using COMSOL software. Combined with ...laboratory experiments, an existing process was improved and optimized by introducing the concept of "precise aeration." The results indicate that aeration can enhance the efficiency of electrochemical demulsification, with the gas field accelerating the deformation, aggregation, and migration processes of the oil droplets. Leveraging the numerical simulation results, laboratory experiments were conducted to optimize the aeration intensity and duration, which were reduced to 1.5 L/min and 60 min. At this point, the oil content and chemical oxygen demand (COD) of the emulsified oil wastewater were only 4.98 mg/L and 101 mg/L, respectively. The demulsification mechanism was analyzed, revealing that under the combined action of the electric field and gas field, oil droplets underwent a polarization reaction and were aggregated into larger droplets. Aeration expedited the weakening of the mechanical strength at the oil-water interface of the droplets, which significantly improved the demulsification, coalescence, and flotation removal of the emulsified oil droplets. This study holds significant importance for the process improvement and mechanistic analysis of electrochemical demulsification for oil removal.
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•Combination of Simulation and Experimental methods on Demulsification of Emulsified Oil.•The concept of "precise aeration" in three-dimensional electrochemistry was first proposed.•Aeration can improve the electrochemical demulsification efficiency.•The optimization of aeration time plays an important role in reducing energy consumption.•The conversion of O2 to H2O2 under the action of the gas field accelerates the rate of demulsification.
This paper proposes a phase field model for fracture in poroelastic media. The porous medium is modeled based on the classical Biot poroelasticity theory and the fracture behavior is controlled by ...the phase field model. Moreover, the fracture propagation is driven by the elastic energy where the phase field is used as an interpolation function to transit fluid property from the intact medium to the fully broken one. We use a segregated (staggered) scheme and implement our approach in Comsol Multiphysics. The proposed model is verified by a single-phase solid subjected to tension and a 2D specimen subjected to an increasing internal pressure. We also compare our results with analytical solutions. Finally, we show 2D and 3D examples of internal fluid injection to illustrate the capability of the proposed approach.
•A phase-field modeling approach of fracture propagation in poroelastic media is proposed.•The fracture propagation is driven by the elastic energy and no stress threshold is set.•2D and 3D examples are presented.
Solid Microneedles
Despite the significance of microneedles for drug delivery, high‐cost, limited‐geometries, and complex fabrication are still hampering their expansion. Xenon difluoride (XeF2) dry ...etching precisely manufactures thousands of microneedles with tunable dimensions and geometries on a single patch. Confirming their penetration with skin models and numerical analyses, these microneedles hold significant potential for noninvasive, pain‐free, and effective drug delivery studies. More details can be found in article number 2206510 by Fatih Inci and co‐workers.
The metal casting process is one of the industry's most significant production processes and is also one of the eco-friendly techniques for making usable parts. Metal smelts are the main melting ...process that takes several stages. However, concerning increased energy consumption, longer casting periods, and major failures, the conventional casting process does have significant problems. New methods are being developed to address these deficiencies of classic casting procedures. The technique of microwave casting is one of the innovative methods that satisfy current needs in the business. The process involves complexity of understanding the heating rate, material interaction phenomenon etc. A 3-D model of the in situ casting process was generated through COMSOL multiphysics software tool. A complete simulation based studies were carried out to predict the thermal history of the metal melting. The simulation results obtained by considering various power levels (1500 W to 3500 W) to predict melting time, average heating rate, desired energy to melt the materials. It was observed that the role of electric field distribution inside the microwave applicator and distribution of the temperature in the charge play a important role at hot spot condition and also to increase in temperature in the charge. It is noted that energy decreases are 15.37% at 3500 W, 9.8% at 2000 W, 16.67% at 2500 W, and 13.6% at 3000 W. Finally, the simulation data showed that the heating of the bulk metal is rapid and consistent at specific location of the mold assembly.
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•Ultrasound scattering theory was used to study agar phantoms doped with the Pickering droplets.•The theoretical ultrasound heating efficiency was affected by the physical properties ...of Pickering droplets.•The adjustment of the core radius and shell thickness of the droplets gave improvement to the modeled ultrasound heating.
Nanoparticles find widespread application in various medical contexts, including targeted nanomedicine and enhancing therapeutic efficacy. Moreover, they are employed to stabilize emulsions, giving rise to stabilized droplets known as Pickering droplets. Among the various methods to improve anti-cancer treatment, ultrasound hyperthermia stands out as an efficient approach. This research proposes Pickering droplets as promising sonosensitizer candidates, to enhance the attenuation of ultrasound with simultaneous potential to act as drug carriers. The enhanced ultrasound energy dissipation could be, therefore, optimized by changing the parameters of Pickering droplets.
The ultrasound scattering theory, based on the core–shell model, was employed to calculate theoretical ultrasound properties such as attenuation and velocity. Additionally, computer simulations, based on a bioheat transfer model, were utilized to compute heat generation in agar-based phantoms of tissues under different ultrasound wave frequencies. Two types of phantoms were simulated: a pure agar phantom and an agar phantom incorporating spherical inclusions. The spherical inclusions, with a diameter of 10 mm, were doped with various sizes of Pickering droplets, considering their core radius and shell thickness.
Computer simulation of these spherical inclusions incorporated within agar phantom resulted in different enhancement of achieved temperature elevation, which depending on the core radius, shell thickness, and the material properties of the system. Notably, spherical inclusions doped with Pickering droplets stabilized by magnetite nanoparticles exhibited a higher temperature rise compared to droplets stabilized by silica nanoparticles. Moreover, nanodroplets with a core radius below 400 nm demonstrated better heating performance compared to microdroplets. Furthermore, Pickering droplets incorporated into agar phantom could allow obtaining a similar effect of local heating as sophisticated focused ultrasound devices.
CFD model for tubular SOFC directly fed by biomass Somano, Valentina; Ferrero, Domenico; Santarelli, Massimo ...
International journal of hydrogen energy,
05/2021, Volume:
46, Issue:
33
Journal Article
Peer reviewed
The coupling between biomass gasification and Solid Oxide Fuel Cells can represent a sustainable and efficient system for electricity production. This work aims to develop a preliminary model for the ...operation of a tubular, electrolyte-supported fuel cell (SOFC) fed by a syngas mixture. The fuel required by the SOFC system is produced inside the energy generator box from an integrated biomass gasification system. This study stems from the European DB-SOFC project, that proposed the exploitation of the abundant biomasses deriving from agricultural residues for energetic purposes (as from olive oil and wine production). In this study, the main processes have been simulated to find a possible configuration to obtain a power value of 200 W. 25 cells were used in the model to produce the required power. The results showed that at 0.7 V it is possible to achieve 12.3 W, when the biomass gasification was integrated into the SOFC box, while it was possible to achieve 9.6 W when the system was fed by externally produced syngas.
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•A direct biomass to SOFC system is modelled.•25 single tubular cells are fed by Olive kernel biomass producing 200 We.•12.3 W from single tubular cells are produced with an integrated biomass system.
The safety concerns associated with lithium-ion batteries (LIBs) have led to the development of a novel framework combining advanced machine learning (ML) techniques with multiphysics modeling. ...Herein, we report an ML framework aiming to predict the occurrence of thermal runaway (TR) in the LIB module by employing a multiphysics model that incorporates thermal, electrochemical, and degradation sub-models. The focus of this research lies in understanding the degradation phenomenon associated with the breakdown of the solid electrolyte interface (SEI) on the negative electrode, which can trigger TR. The developed multiphysics model enables the investigation of electrochemical and degradation processes within batteries under various conditions, including constant charge/discharge and driving cycles. To capture the spatio-temporal temperature change, a graph neural network (GNN) for spatial change is coupled with a Long Short-Term Memory (LSTM) network for temporal evolution to form an integrated framework. The results demonstrate the high accuracy of the ML model in predicting battery temperatures in a module based on spatial and temporal temperature data obtained from temperature sensors attached to the batteries, hence, offering a means to detect TR before it occurs by identifying potential thermal hotspots.
•A multiphysics model of thermal runaway in a battery module is developed.•The decomposition of solid electrolyte interface is considered.•Machine learning was implemented to predict temperature during battery operation.•A modeling method was implemented to generate realistic data on EV driving behavior.
The objective of the research is to present an investigation on the operational performance of the integrated photovoltaic/thermal system (PV/T) and solar thermal collector (TC) with a heat pump ...system (PVT-TC) and its potential use for generating high thermal energy and electricity simultaneously. The numerical simulation model and testing rig of the PVT-TC heat pump system have been developed to analyze the electrical, thermal, and total efficiency of the system. An experimental test was carried out under real weather conditions. The experimental results revealed that the average electrical, thermal efficiency, and coefficient of performance (COP) of the PVT-TC heat pump system are 14.08%, 66.71%, and 6.11, respectively. According to comparative analysis with the similar systems, the PVT-TC heat pump system exhibits a higher electrical and thermal efficiency, thus showing a better application potential in residential buildings. The PVT-TC system occupies 3.3278 m2 and generates an average of 0.86 kWh/day of electricity and 6.35 kWh/day of thermal energy, as a result of 86.1% of primary energy saving efficiency being obtained. In addition, the PVT-TC heat pump system is simulated using COMSOL Multiphysics® to examine the temperature distribution of the solar TC and PV/T systems. The numerical model is also verified by the experimental data, with a root mean square deviation with less than 1.53%.
•A novel PVT-TC system coupled with a solar direct-expansion heat pump system.•An experimental study was conducted to analyze the performance of the novel system.•The average COP of the PVT-TC solar heat pump system was obtained to be 6.11•Average thermal efficiency of PVT-TC system was achieved to be 66.71%.
Thermal effect is inevitable during laser processing and is easy to induce cracks and damage on the hard and brittle materials, especially. The crack generation mechanism during laser ablation of ...single hole and groups of holes on alumina ceramic has been investigated. A heat conduction model of the nanosecond laser processing of a group of holes has been developed. The temperature field over a AL2O3 sample was modeled and simulated using COMSOL multi-physics. The temperature distribution on the AL2O3 sample was experimentally verified using an infrared thermometer. The present research provides guidance for the high-quality laser machining of group holes over large areas.
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