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F Gori - One of the best experts on this subject based on the ideXlab platform.

  • mass and energy capital Conservation Equations to study the price evolution of non renewable energy resources part i generalization of the hotelling rule
    Applied Thermal Engineering, 2006
    Co-Authors: F Gori
    Abstract:

    Abstract Mass Conservation Equation of non-renewable resources is employed to study the resources remaining in the reservoir according to the extraction policy. The energy Conservation Equation is transformed into an energy-capital Conservation Equation. The Hotelling rule is shown to be a special case of the general energy-capital Conservation Equation when the mass flow rate of extracted resources is equal to unity. Mass and energy-capital Conservation Equations are then coupled and solved together. It is investigated the price evolution of extracted resources. The conclusion of the Hotelling rule for non-extracted resources, i.e. an exponential increase of the price of non-renewable resources at the rate of current interest, is then generalized. A new parameter, called “Price Increase Factor”, PIF, is introduced as the difference between the current interest rate of capital and the mass flow rate of extraction of non-renewable resources. The price of extracted resources can increase exponentially only if PIF is greater than zero or if the mass flow rate of extraction is lower than the current interest rate of capital. The price is constant if PIF is zero or if the mass flow rate of extraction is equal to the current interest rate. The price is decreasing with time if PIF is smaller than zero or if the mass flow rate of extraction is higher than the current interest rate.

Irina Dymnikova - One of the best experts on this subject based on the ideXlab platform.

  • the algebraic structure of a cosmological term in spherically symmetric solutions
    Physics Letters B, 2000
    Co-Authors: Irina Dymnikova
    Abstract:

    Abstract We propose to describe the dynamics of a cosmological term in the spherically symmetric case by an r -dependent second rank symmetric tensor Λ μν invariant under boosts in the radial direction. This proposal is based on the Petrov classification scheme and Einstein field Equations in the spherically symmetric case. The inflationary Equation of state p =− ρ is satisfied by the radial pressure, p r Λ =− ρ Λ . The tangential pressure p ⊥ Λ is calculated from the Conservation Equation Λ μ ν ; μ =0.

  • the algebraic structure of a cosmological term in spherically symmetric solutions
    arXiv: General Relativity and Quantum Cosmology, 1999
    Co-Authors: Irina Dymnikova
    Abstract:

    We propose to describe the dynamics of a cosmological term in the spherically symmetric case by an r-dependent second rank symmetric tensor invariant under boosts in the radial direction. This proposal is based on the Petrov classification scheme and Einstein field Equations in the spherically symmetric case. The inflationary Equation of state p=-\rho is satisfied by the radial pressure. The tangential pressure is calculated from the Conservation Equation (the contracted Bianchi identity).

Sebastien Motsch - One of the best experts on this subject based on the ideXlab platform.

  • continuum limit of self driven particles with orientation interaction
    Mathematical Models and Methods in Applied Sciences, 2008
    Co-Authors: Pierre Degond, Sebastien Motsch
    Abstract:

    The discrete Couzin–Vicsek algorithm (CVA), which describes the interactions of individuals among animal societies such as fish schools is considered. In this paper, a kinetic (mean-field) version of the CVA model is proposed and its formal macroscopic limit is provided. The final macroscopic model involves a Conservation Equation for the density of the individuals and a non-conservative Equation for the director of the mean velocity and is proved to be hyperbolic. The derivation is based on the introduction of a non-conventional concept of a collisional invariant of a collision operator.

  • continuum limit of self driven particles with orientation interaction
    arXiv: Mathematical Physics, 2007
    Co-Authors: Pierre Degond, Sebastien Motsch
    Abstract:

    We consider the discrete Couzin-Vicsek algorithm (CVA), which describes the interactions of individuals among animal societies such as fish schools. In this article, we propose a kinetic (mean-field) version of the CVA model and provide its formal macroscopic limit. The final macroscopic model involves a Conservation Equation for the density of the individuals and a non conservative Equation for the director of the mean velocity and is proved to be hyperbolic. The derivation is based on the introduction of a non-conventional concept of a collisional invariant of a collision operator.

Qingshan Zhu - One of the best experts on this subject based on the ideXlab platform.

  • simulation of gas solid flow in 2d 3d bubbling fluidized beds by combining the two fluid model with structure based drag model
    Chemical Engineering Journal, 2014
    Co-Authors: Qingshan Zhu
    Abstract:

    Abstract In this work, a new method was developed to simulate bubbling fluidized beds with Geldart A particles by modifying the conventional drag correlations through considering the effect of the non-uniform flow structure. In this method, seven local structural parameters (ɛe, Uge, fb, Ub, Ugb, db, ab), which were used to describe the internal flow structure of bubbling fluidized beds, were obtained by solving seven independent Equations made up of momentum Conservation Equation, mass Conservation Equation, and empirical correlations. The structure-based drag correlation was incorporated into the two-fluid model to simulate the hydrodynamics of Geldart A particles in bubbling fluidized beds, where the simulated results showed good agreements with those experimental data for the axial and radial solid concentration profiles. The solid circulation pattern in the 2D bubbling fluidized bed was also captured.

Hongliang Yi - One of the best experts on this subject based on the ideXlab platform.

  • lattice boltzmann model for coulomb driven flows in dielectric liquids
    Physical Review E, 2016
    Co-Authors: Jian Wu, Hongliang Yi
    Abstract:

    : In this paper, we developed a unified lattice Boltzmann model (LBM) to simulate electroconvection in a dielectric liquid induced by unipolar charge injection. Instead of solving the complex set of coupled Navier-Stokes Equations, the charge Conservation Equation, and the Poisson Equation of electric potential, three consistent lattice Boltzmann Equations are formulated. Numerical results are presented for both strong and weak injection regimes, and different scenarios for the onset and evolution of instability, bifurcation, and chaos are tracked. All LBM results are found to be highly consistent with the analytical solutions and other numerical work.