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Commercial supercapacitor parameter estimation from step voltage excitation
Supercapacitors are crucial elements in advanced industrial electronic systems particularly when supplied from renewable energy sources. Here, we derive expressions for the current, power, and stored energy in a supercapacitor excited with a step voltage signal. Although, it is not common practice to charge supercapacitors using a step voltage, these devices are sometimes used in switching-type applications where they are subject to this type of signal. We validate the derived mathematical expression of the current via experiments on four different commercial devices. By fitting the measured
J-V characteristics of plasmonic photovoltaics with embedded conical and cylindrical metallic nanoparticles
Plasmonic photovoltaics (PVs) are promising structures that improve thin-film photovoltaics performance, where optical absorption is improved via embedding metallic nanoparticles in the PV's active layer to trap the incident optical wave into the photovoltaic cell. The presented work investigates the design of PV with both structures of conical and cylindrical metallic nanoparticles through studying their extinction cross-sections and electric field distributions. Also, the impact of these nanoparticles in silicon PVs on the optical absorption enhancement is investigated. The figure of merit
Analytical solution for fractional derivative gas-flow equation in porous media
In this paper, we introduce an analytical solution of the fractional derivative gas transport equation using the power-series technique. We present a new universal transform, namely, generalized Boltzmann change of variable which depends on the fractional order, time and space. This universal transform is employed to transfer the partial differential equation into an ordinary differential equation. Moreover, the convergence of the solution has been investigated and found that solutions are unconditionally converged. Results are introduced and discussed for the universal variable and other
Fractional-Order Model (FOM) for high-strength substrate biodegradation in conventional UASB reactor
This paper introduces a Fractional-Order Model (FOM) of Up-flow Anaerobic Sludge Blanket (UASB) reactor for wastewater treatment regarding high-strength substrate biodegradation. The model can investigate the biogas production rate as well as the specific growth rate of bacteria with extra degree of freedom. Also, the hereditary effect of resident biomass on substrate degradation is studied on periodically long terms. Moreover, biomass concentration is examined in reactor under the influence of various fractional orders. Several numerical simulation results are introduced based on Grünwald
Modified kinetic-hydraulic UASB reactor model for treatment of wastewater containing biodegradable organic substrates
This paper addresses a modified kinetic-hydraulic model for up-flow anaerobic sludge blanket (UASB) reactor aimed to treat wastewater of biodegradable organic substrates as acetic acid based on Van der Meer model incorporated with biological granules inclusion. This dynamic model illustrates the biomass kinetic reaction rate for both direct and indirect growth of microorganisms coupled with the amount of biogas produced by methanogenic bacteria in bed and blanket zones of reactor. Moreover, the pH value required for substrate degradation at the peak specific growth rate of bacteria is
Novel 3D memory-centric NoC architecture for transaction-based SoC applications
Large and complex system-on-chip devices consisting of many processor cores, accelerators, DSP functions and many other processing and memory elements are becoming common in the semiconductor industry nowadays. To communicate, these processing and memory elements need to have a network-on-chip (NoC) that is scalable enough to support large number of elements and large bandwidth among other requirements. This paper evaluates the performance of the 2D memory-centric NoC architecture from throughput and latency perspective versus the Mesh topology. We also propose a memory-centric architecture
Frequency-dependent effective capacitance of supercapacitors using electrospun cobalt-carbon composite nanofibers
Mixing carbon-based materials with pseudocapacitive material is a widely used strategy to prepare high-energy, high-power supercapacitors. However, phase separation is inevitable after extended charging/discharging which leads to the degradation of performance metrics of the device. Here, we prepare in a single step cobalt-incorporated carbon nanofibers (CNF) by electrospinning homogeneous solutions of polyacrylonitrile (PAN) with cobalt acetate at different nominal proportions (1:0 to 1:1), and investigate their stability and capacitive behavior in symmetric supercapacitors. The
Highlighting a Common Confusion in the Computation of Capacitance of Electrochemical Energy Storage Devices
[No abstract available]
Two-dimensional front-tracking model for film evaporation
To understand the physical process involved in film evaporation, a new numerical model is created using coupled quadratic finite element formulation of the conservation equations. The heat transport equation is solved in the three different phases (solid, liquid and vapor) while the Navier-Stokes equation are solved in the two fluids. The gradient discontinuity at the liquid vapor interface provides local value of the evaporative flux density that is directly linked to the interface velocity jump through mass conservation principle and used as boundary condition for two fluid flow computations
Interfacial modification of perovskite solar cell using zno electron injection layer with pdms as antireflective coating
Recently, perovskite solar cells (PSCs) exhibits tremendous power conversion efficiency and has shown enhanced figures of merit being secured regarding cell stability. In this paper, perovskite solar cell with Zno electron injection layer is presented. The humidity degradation of the perovskite active layer and the efficiency of the cell is observed under several conditions. Using ZnO as a planner electron injection layer (EIL) instead of TiO2, the efficiency of the device significantly improved, showing low-resistance shunting pathways. Also, polydimethylsiloxane (PDMS) has been used as a
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