Results 111 to 120 of about 218,744 (163)

Energy density and energy flux in the focus of an optical vortex: reverse flux of light energy

Optics Letters, 2018
Using the Richards-Wolf formulas for an arbitrary circularly polarized optical vortex with an integer topological charge m, we obtain explicit expressions for all components of the electric and magnetic field strength vectors near the focus, as well as expressions for the intensity (energy density) and for the energy flux (components of the Poynting ...
Victor V. Kotlyar, Alexey A. Kovalev, Anton G. Nalimov   +2 more
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Energy fluxes and their relations within energy plants

Energy Conversion and Management, 2007
Analysing how energy is delivered from its primary sources to final users, it may be seen that the evolution of technology, driven by economic considerations, has mainly rewarded those systems that have intense energy fluxes through their main sections.
GRAZZINI, GIUSEPPE, MILAZZO, ADRIANO
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Neutron Flux and Energy Measurements

Physics in Medicine & Biology, 1966
The problem of neutron energy measurement is considered in the energy ranges, thermal ( 15 MeV), together with the general problem of neutron flux measurement. Sensitivities and resolutions obtainable are given for a variety of methods. It is concluded that for thermal and intermediate energy measurements in radiological applications it is best to use
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ELECTROMAGNETIC ENERGY DENSITY AND FLUX

Canadian Journal of Physics, 1952
Although Poynting's theorem receives general acceptance in the treatment of electromagnetic energy, an alternative theorem, Macdonald's, has equal claim to validity at the present state of our knowledge. In a comparison of many results derived from the two, Macdonald's theorem exhibits sufficient superiority to warrant its consideration more generally
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Intuitive and Counterintuitive Energy Flux

Archive for Rational Mechanics and Analysis, 2004
The author considers the estimation of flux and absolute flux of energy across hypersurfaces for regular solutions to heat, wave and Schrödinger equations in \(\mathbb{R}_t \times \mathbb{R}^{d}_x\), \(d \geq 1\). The main result is that the absolute flux of energy across hypersurfaces is as large as one wants compared to the total energy.
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ENERGY AND HEAT FLUX

International Journal of Modern Physics D, 1995
The total energy in a sphere containing an isotropic shear-free conducting heat fluid is studied in the frame of a spherically symmetric metric. Firstly, we examine the role played by the heat flux. Secondly, we point out the contribution to the energy by the Weyl tensor.
J. GARIEL, N.O. SANTOS, G. LE DENMAT
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Energy-Flux Operator for a Lattice

Physical Review, 1963
A systematic derivation of the energy-flux operator for a three-dimensional lattice is given. The treatment is based on the general expressions for the energy flux which are valid for all phases of matter; a short derivation of these expressions, making no restrictions to two-body forces, is presented.
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Constraints on negative-energy fluxes

Physical Review D, 1991
Locally negative energy due to quantum coherence effects in quantum field theory is discussed. In a previous work, it was argued that a beam carrying negative energy must satisfy an uncertainty-principle-type inequality of the form \ensuremath{\Vert}\ensuremath{\Delta}E\ensuremath{\Vert}\ensuremath{\Delta}t\ensuremath{\le}1, where \ensuremath{\Vert ...
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Energy Requirements and Energy Flux

1997
The energy yield and nutritive value of food is a function of its composition and digestibility. The chemical energy content, or gross energy, of food (Table 7.1) is equivalent to the heat produced on combustion of its total organic matter. It is expressed in joules; 4.184 joules (1 calorie) is the amount of heat required to raise the temperature of lg
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