Effective equation of motion for gas–solid interactions

1987 ◽  
Vol 86 (12) ◽  
pp. 7181-7188 ◽  
Author(s):  
Yehuda Zeiri
Keyword(s):  
Equation Of Motion ◽  
Effective Equation

scholarly journals A TOPOLOGICAL EXTENSION OF GENERAL RELATIVITY TO EXPLORE THE NATURE OF QUANTUM SPACETIME, DARK ENERGY AND INFLATION

2013 ◽  
Vol 22 (10) ◽  
pp. 1330022
Author(s):  
M. SPAANS
Keyword(s):  
General Relativity ◽  
Dark Energy ◽  
Discrete Time ◽  
Thought Experiment ◽  
Planck Scale ◽  
Equation Of Motion ◽  
Effective Equation ◽  
Dark Energy Density ◽  
Topological Quantum ◽  
Quantum Spacetime

General Relativity is extended into the quantum domain. A thought experiment is explored to derive a specific topological build-up for Planckian spacetime. The presented arguments are inspired by Feynman's path integral for superposition and Wheeler's quantum foam of Planck mass mini black holes (BHs)/wormholes. Paths are fundamental and prime three-manifolds like T3, S1 × S2 and S3 are used to construct quantum spacetime. A physical principle is formulated that causes observed paths to multiply: It takes one to know one. So topological fluctuations on the Planck scale take the form of multiple copies of any homeomorphically distinct path through quantum spacetime. The discrete time equation of motion for this topological quantum gravity is derived by counting distinct paths globally. The equation of motion is solved to derive some properties of dark energy and inflation. The dark energy density depends linearly on the number of macroscopic BHs in the universe and is time-dependent in a manner consistent with current astrophysical observations, having an effective equation of state w ≈ -1.1 for redshifts smaller than unity. Inflation driven by mini BHs proceeds over n ≈ 55 e-foldings, without strong inhomogeneity. A discrete time effect visible in the cosmic microwave background is suggested.

MOMENTS OF THE SPIN-DEPENDENT PROTON STRUCTURE FUNCTION

1990 ◽  
Vol 05 (14) ◽  
pp. 1125-1130
Author(s):  
D. INDUMATHI ◽  
M. V. N. MURTHY ◽  
V. RAVINDRAN
Keyword(s):  
Structure Function ◽  
Operator Product Expansion ◽  
Equation Of Motion ◽  
Proton Structure Function ◽  
Operator Product ◽  
Effective Equation ◽  
The Third ◽  
Proton Structure ◽  
First Moment ◽  
Third Moment

We discuss the moments of the recently measured spin-dependent structure function, [Formula: see text], of the proton. Using the operator product expansion and an effective equation of motion, we show that the third moment can be related to the first moment.

scholarly journals Application of the method of asymptotic homogenization to an acoustic metafluid

2011 ◽  
Vol 467 (2135) ◽  
pp. 3318-3331 ◽  
Author(s):  
John D. Smith
Keyword(s):  
Material Properties ◽  
Effective Properties ◽  
Low Frequency ◽  
Equation Of Motion ◽  
Effective Equation ◽  
Asymptotic Homogenization ◽  
Effective Wave ◽  
Dynamic Effective Properties ◽  
Anisotropic Stiffness ◽  
Natural Way

The method of asymptotic homogenization is used to find the dynamic effective properties of a metamaterial consisting of two alternating layers of fluid, repeating periodically. As well as the effective wave equation, the method gives the effective equation of motion and constitutive relation in a natural way. When the material properties are such that resonant effects can be present in one of the layers, it is found that the metamaterial changes dynamically from a metafluid with anisotropic density and isotropic stiffness at low frequency to one with anisotropic stiffness when the frequency is near to one of the local resonances. In this region of frequency, the resulting metamaterial is not a pentamode material and thus does not belong to the class of metafluids that can be transformed to an isotropic fluid by a coordinate transformation.

scholarly journals Perturbation analysis of the effective equation for two coupled periodically driven oscillators

2006 ◽  
Vol 2006 ◽  
pp. 1-10 ◽  
Author(s):  
Andrzej Okniński ◽  
Jan Kyzioł
Keyword(s):  
Dynamical System ◽  
Perturbation Analysis ◽  
Approximate Equation ◽  
Equation Of Motion ◽  
Internal Motion ◽  
Effective Equation ◽  
Periodically Driven

Dynamics of two coupled periodically driven oscillators is analyzed via approximate effective equation of motion. The internal motion is separated off exactly and then approximate equation of motion is derived. Perturbation analysis of the effective equation is used to study the dynamics of the initial dynamical system.

scholarly journals The Effective Equation of Motion on the Brane World Gravity

2006 ◽  
Vol 38 (1) ◽  
pp. 1-20
Author(s):  
F. P. Zen ◽  
Arianto ◽  
B. E. Gunara ◽  
H. Zainuddin
Keyword(s):  
Equation Of Motion ◽  
Brane World ◽  
Effective Equation

scholarly journals On causal structure of 4D-Einstein–Gauss–Bonnet black hole

2020 ◽  
Vol 80 (9) ◽  
Author(s):  
Naresh Dadhich
Keyword(s):  
Black Hole ◽  
Black Hole Solution ◽  
Causal Structure ◽  
Equation Of Motion ◽  
Cauchy Horizon ◽  
Coupling Constant ◽  
Schwarzschild Black Hole ◽  
Effective Equation ◽  
Central Singularity ◽  
Static Black Hole

AbstractThe recently proposed effective equation of motion for the 4D-Einstein–Gauss–Bonnet gravity admits a static black hole solution that has, like the Rissner–Nordström charged black hole, two horizons instead of one for the Schwarzschild black hole. This means that the central singularity is timelike instead of spacelike. It should though be noted that in $$D\ge 5$$ D ≥ 5 , the solution always admits only one horizon like the Schwarzshild solution. In the equation defining the horizon, the rescaled Gauss–Bonnet coupling constant appears as a new ‘gravitational charge’ with a repulsive effect to cause in addition to event horizon a Cauchy horizon. Thus it radically alters the causal structure of the black hole.

Particle motion with air resistance

2012 ◽  
Vol 8 (1) ◽  
pp. 1-15
Author(s):  
Gy. Sitkei
Keyword(s):  
Basic Equation ◽  
Initial Conditions ◽  
Equation Of Motion ◽  
Terminal Velocity ◽  
Dimensionless Form ◽  
Wood Industry ◽  
Acceptable Error ◽  
General Validity ◽  
Practical Applications ◽  
Air Resistance

Motion of particles with air resistance (e.g. horizontal and inclined throwing) plays an important role in many technological processes in agriculture, wood industry and several other fields. Although, the basic equation of motion of this problem is well known, however, the solutions for practical applications are not sufficient. In this article working diagrams were developed for quick estimation of the throwing distance and the terminal velocity. Approximate solution procedures are presented in closed form with acceptable error. The working diagrams provide with arbitrary initial conditions in dimensionless form of general validity.

Finite difference code for velocity and surface traction of a Fluid between Two Eccentric Spheres

2015 ◽  
Vol 11 (1) ◽  
pp. 2960-2971
Author(s):  
M.Abdel Wahab
Keyword(s):  
Velocity Field ◽  
Angular Velocity ◽  
Finite Difference ◽  
Numerical Study ◽  
Outer Sphere ◽  
Equation Of Motion ◽  
Annular Region ◽  
Surface Traction ◽  
Angular Velocities ◽  
Axis Passing

The Numerical study of the flow of a fluid in the annular region between two eccentric sphere susing PHP Code isinvestigated. This flow is created by considering the inner sphere to rotate with angular velocity 1  and the outer sphererotate with angular velocity 2  about the axis passing through their centers, the z-axis, using the three dimensionalBispherical coordinates (, ,) .The velocity field of fluid is determined by solving equation of motion using PHP Codeat different cases of angular velocities of inner and outer sphere. Also Finite difference code is used to calculate surfacetractions at outer sphere.

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