The electromagnetic energy and momentum of finite charged bodies moving at constant velocity

1975 ◽  
Vol 13 (2) ◽  
pp. 103-111
Author(s):  
Roger Stettner
Keyword(s):  
Constant Velocity ◽  
Electromagnetic Energy ◽  
Energy And Momentum

scholarly journals Northern preference for terrestrial electromagnetic energy input from space weather

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
I. P. Pakhotin ◽  
I. R. Mann ◽  
K. Xie ◽  
J. K. Burchill ◽  
D. J. Knudsen
Keyword(s):  
Space Weather ◽  
Energy Input ◽  
Rotation Axis ◽  
Electromagnetic Energy ◽  
Magnetic Pole ◽  
Poynting Flux ◽  
Auroral Emissions ◽  
Energy And Momentum ◽  
Swarm Satellite ◽  
Northern And Southern Hemispheres

AbstractTerrestrial space weather involves the transfer of energy and momentum from the solar wind into geospace. Despite recently discovered seasonal asymmetries between auroral forms and the intensity of emissions between northern and southern hemispheres, seasonally averaged energy input into the ionosphere is still generally considered to be symmetric. Here we show, using Swarm satellite data, a preference for electromagnetic energy input at 450 km altitude into the northern hemisphere, on both the dayside and the nightside, when averaged over season. We propose that this is explained by the offset of the magnetic dipole away from Earth’s center. This introduces a larger separation between the magnetic pole and rotation axis in the south, creating different relative solar illumination of northern and southern auroral zones, resulting in changes to the strength of reflection of incident Alfvén waves from the ionosphere. Our study reveals an important asymmetry in seasonally averaged electromagnetic energy input to the atmosphere. Based on observed lower Poynting flux on the nightside this asymmetry may also exist for auroral emissions. Similar offsets may drive asymmetric energy input, and potentially aurora, on other planets.

Propagation of electromagnetic energy and momentum through an absorbing dielectric

1997 ◽  
Vol 55 (1) ◽  
pp. 1071-1085 ◽  
Author(s):  
R. Loudon ◽  
L. Allen ◽  
D. F. Nelson
Keyword(s):  
Electromagnetic Energy ◽  
Energy And Momentum

Electromagnetic energy and momentum conservation in pendulum experiments

2003 ◽  
Vol 39 (4) ◽  
pp. 2024-2029 ◽  
Author(s):  
P.G. Moyssides ◽  
C. Patrinos ◽  
P. Hatzikonstantinou
Keyword(s):  
Momentum Conservation ◽  
Electromagnetic Energy ◽  
Energy And Momentum

Analysis of Hydrodynamic Penetration and Material Backflow

2007 ◽  
Author(s):  
David Lambert
Keyword(s):  
Constant Velocity ◽  
Momentum Flux ◽  
Interface Velocity ◽  
Dimensional Theory ◽  
One Dimensional ◽  
First Order ◽  
Design Considerations ◽  
Rule Approach ◽  
Energy And Momentum ◽  
D Model

One-dimensional theory of hydrodynamic penetration for incompressible, inviscid conditions is re-visited to derive insightful relationships and provide a basis for discussing experimental observations. The 1-D Bernoulli equation produces simplified analytical relationships for such terms as the penetration depth, penetrator erosion rate, interface velocity, and other fundamental terms. Previous efforts [1,2] expanded this via a differential chain rule approach to establish relationships of energy and momentum flux and deposition rates of constant velocity and linear velocity gradient rod penetration events. A concise overview of the 1-D model is given followed by a selective grouping into relationships that might provide first-order criteria for making design considerations.

Record Wear Studies by Scanning Electron Microscopy

1968 ◽  
Vol 26 ◽  
pp. 364-365
Author(s):  
M.D. Coutts ◽  
E.R. Levin ◽  
J.G. Woodward
Keyword(s):  
Electron Microscopy ◽  
Constant Velocity ◽  
Peak Velocity ◽  
Great Depth ◽  
Depth Of Focus ◽  
Sweep Frequency ◽  
Transmission Electron ◽  
Test Record ◽  
Lateral Mode ◽  
Scanning Electron

While record grooves have been studied by transmission electron microscopy with replica techniques, and by optical microscopy, the former are cumbersome and restricted and the latter limited by lack of depth of focus and resolution at higher magnification. With its great depth of focus and ease in specimen manipulation, the scanning electron microscope is admirably suited for record wear studies.A special RCA sweep frequency test record was used with both lateral and vertical modulation bands. The signal is a repetitive, constant-velocity sweep from 2 to 20 kHz having a duration and repetitive rate of approximately 0.1 sec. and a peak velocity of 5.5 cm/s.A series of different pickups and numbers of plays were used on vinyl records. One centimeter discs were then cut out, mounted and coated with 200 Å of gold to prevent charging during examination. Wear studies were made by taking micrographs of record grooves having 1, 10 and 50 plays with each stylus and comparing with typical “no-play” grooves. Fig. 1 shows unplayed grooves in a vinyl pressing with sweep-frequency modulation in the lateral mode.

Plasmon-assisted interaction of Si with light, for cancer hyperthermia and electromagnetic energy harvest

2020 ◽  
Vol 92 (2) ◽  
pp. 20101
Author(s):  
Behnam Kheyraddini Mousavi ◽  
Morteza Rezaei Talarposhti ◽  
Farshid Karbassian ◽  
Arash Kheyraddini Mousavi
Keyword(s):  
Silicon Nanowires ◽  
Metallic Nanoparticles ◽  
Near Infrared ◽  
Optical Transition ◽  
Electromagnetic Energy ◽  
Energy Harvest ◽  
Absorption Enhancement ◽  
Ir Absorption ◽  
Absorption Mechanism ◽  
Near Ir

Metal-assisted chemical etching (MACE) is applied for fabrication of silicon nanowires (SiNWs). We have shown the effect of amorphous sheath of SiNWs by treating the nanowires with SF6 and the resulting reduction of absorption bandwidth, i.e. making SiNWs semi-transparent in near-infrared (IR). For the first time, by treating the fabricated SiNWs with copper containing HF∕H2O2∕H2O solution, we have generated crystalline nanowires with broader light absorption spectrum, up to λ = 1 μm. Both the absorption and photo-luminescence (PL) of the SiNWs are observed from visible to IR wavelengths. It is found that the SiNWs have PL at visible and near Infrared wavelengths, which may infer presence of mechanisms such as forbidden gap transitions other can involvement of plasmonic resonances. Non-radiative recombination of excitons is one of the reasons behind absorption of SiNWs. Also, on the dielectric metal interface, the absorption mechanism can be due to plasmonic dissipation or plasmon-assisted generation of excitons in the indirect band-gap material. Comparison between nanowires with and without metallic nanoparticles has revealed the effect of nanoparticles on absorption enhancement. The broader near IR absorption, paves the way for applications like hyperthermia of cancer while the optical transition in near IR also facilitates harvesting electromagnetic energy at a broad spectrum from visible to IR.

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