This study investigate the morphology of oil-in-water at high density ratio controlled by electric field. We incorporated the electric field into the Lattice Boltzmann method (LBM). The focus is on ...the modified lattice Boltzmann color gradient model simulate the evolution of the oil-in-water and analyze the relation between morphologies and electric field parameters. The results show that the stretching, merging and even breaking can be regulated by electric field strength, conductivity, dielectric constant, oil-water density ratio and droplet radius. Simulation results showed that the larger dielectric constant resulted in the smaller deformation, and the larger conductivity related to the greater deformation. Meanwhile, the larger radius droplet is easier to deform and break, and the higher density droplet is less likely to break. And this paper also gives the morphology of the stretching and destabilization of the droplets at each stage. These results are in good agreement with the relevant theoretical and experimental results.
With the development of smart grids, the demand for monitoring the condition of transmission is becoming high. Harvesting magnetic energy of transmission lines is a feasible approach to provide a ...sustainable power source for condition monitoring sensors. However, energy harvesting methods for transmission lines are constrained by size and service life. We report an antifatigue triboelectric nanogenerator based on a swinging structure (S-TENG) for magnetic energy harvesting. The S-TENG is composed of several magnets attached to a flexible substrate, which is laminated with a sponge layer, a copper film, and a polytetrafluoroethylene film. The laminated layer acts both as a tribo-layer and as a beam. The distinct structure without a stiff termination also avoids vibration fatigue and ensures the efficient contact of triboelectric layers with each other. The S-TENG presents a maximum peak power of 0.78 mW under 30 MΩ loading resistance. This work reveals the potential for harvesting alternating magnetic energy of transmission lines as an energy source for low-power electronic appliances.
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•The nanogenerator was operated using magnetic energy of transmission lines.•Contact-separation mode was applied to the nanogenerator based on swinging structure.•The nanogenerator was convenient to fabricate and could be positioned on the pylon without tedious steps.•The tribo-layer was driven by magnetic force.•The S-TENG has readily charged capacitors to drive low-power electronic appliances such as sensors and a self-powered alarm system.
In this paper, the two-dimensional Kelvin–Helmholtz (KH) instability occurring in the shear flow of polymer fluids is modeled by the dissipative particle dynamics (DPD) method at the coarse-grained ...molecular level. A revised FENE model is proposed to properly describe the polymer chains. In this revised model, the elastic repulsion and tension are both considered between the adjacent beads, the bond length of which is set as one segment’s equilibrium length. The entanglements between polymer chains are described with a bead repulsive potential. The characteristics of such a KH instability in polymer fluid shear flow can be successfully captured in the simulations by the use of the modified FENE model. The numerical results show that the waves and vortexes grow more slowly in the shear flow of the polymer fluids than in the Newtonian fluid case, these vortexes become flat, and the polymer impedes the mixing of fluids and inhibits the generation of turbulence. The effects of the polymer concentration, chain length, and extensibility are also investigated regarding the evolution of KH instability. It is shown that the mixing of two polymer fluids reduces, and the KH instability becomes more suppressed as the polymer concentration increases. The vortexes become much longer with the evolution of the elongated interface as the chain length turns longer. As the extensibility increases, the vortexes become more flattened. Moreover, the roll-up process is significantly suppressed if the polymer has sufficiently high extensibility. These observations show that the polymer and its properties significantly influence the formation and evolution of the coherent structures such as the waves and vortexes in the KH instability progress.
Purpose
Poor structure, nutrient deficiency, and acidification are core factors restricting the reclamation of rare earth mining wasteland soil (REMWS). Sewage sludge, bagasse, and molybdenum ...tailings, all of which need proper disposal, have great potentials in REMWS reclamation. The goal of this study was to explore the remediation effect on rare earth mining wasteland soil with the combined application of sewage sludge compost (SSC), bagasse, and modified molybdenum tailings (MMT).
Materials and methods
SSC (T1), SSC + bagasse (T2), and SSC + bagasse + MMT (T3) were applied in REMWS as amendments in a 4-month pot experiment, and their effects on REMWS properties and heavy metals (HMs) toxicity were tested with
Eucalyptus urophylla
, which grows fast, resists environment stress, and is a promising plant in REMWS reclamation.
Results
The application of SSC (T1) improved REMWS fertility, but increased Cu, Zn, Cd, and Ni contents in soil and
E. urophylla
seedlings, and inhibited
E. urophylla
growth
.
Bagasse application (T2) alleviated growth inhibition and further addition of bagasse + MMT (T3) significantly improved
E. urophylla
growth. Moreover, T3 improved soil physical properties, organic carbon content, pH, and reduced soil HMs bioavailability and plant HMs content as compared to T1 and T2. Structural equation modeling results revealed that plant nutrient accumulation increased plant HMs accumulation, the latter inhibited plant nutrient accumulation in turn, and soil pH played a key role in retarding HMs uptake and improving
E. urophylla
growth and nutrients uptake.
Conclusion
These results suggested that the combined application of SSC, bagasse, and MMT is an effective approach for REMWS amelioration and land disposal of solid waste resources.
This paper proposes a model predictive control of open irrigation canals with constraints. The Saint-Venant equations are widely used in hydraulics to model an open canal. As a set of hyperbolic ...partial differential equations, they are not solved explicitly and difficult to design optimal control algorithms. In this work, a prediction model of an open canal is developed by discretizing the Saint-Venant equations in both space and time. Based on the prediction model, a constrained model predictive control was firstly investigated for the case of one single-pool canal and then generalized to the case of a cascaded canal with multipools. The hydraulic software SICC was used to simulate the canal and test the algorithms with application to a real-world irrigation canal of Yehe irrigation area located in Hebei province.
Based on the principle of proportion sharing and Kirchhoff's theorem, this paper proposed a efficient power flow tracking analytical algorithm. According to the calculation results, this method can ...generate the down-flow and counter-flow matrix, and obtain single source or single flow coefficient through the Gaussian elimination method. The proposed method can avoid the inverse matrix in the past analytical algorithm, greatly reduce calculation burden, and provide the power flow tracing parallel algorithm, which provide a basis for the application of power flow tracing in large scale power grid. This paper test the correctness of the proposed method in 2 machine 4 node test system, and prove the efficiency in several real power grids.
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