Results 261 to 270 of about 2,275,236 (300)

Null cone computation of gravitational radiation

Journal of Mathematical Physics, 1983
The production of gravitational waves is explored, both analytically and numerically, using a null cone formulation of axially symmetric gravitational and matter fields. The coupled field equations are written in an integral form, on a single conformally compactified patch, which is well suited for numerical computation.
R. A. Isaacson, J. S. Welling, J. Winicour   +2 more
openaire   +1 more source

Slotted Waveguide Antenna With Two Radiation Nulls

IEEE Transactions on Antennas and Propagation, 2008
A design of a linear array antenna having two radiation nulls and otherwise omnidirectional radiation pattern is reported. A new configuration of a waveguide broad wall longitudinal slot doublet with positive and negative offsets with respect to the waveguide center line is used to design the array.
Priyanka Mondal, Ajay Chakrabarty
openaire   +1 more source

The Methods for Generating Radiation Null in Filtering Antennas

2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall), 2019
Filtering antennas have been achieved more attention for the advantages of reducing the requirement of the filter in wireless communication systems. The radiation nulls of filtering antenna can further improve the frequency selectivity and decrease the mutual coupling between the closely placed antennas operating at different frequencies so that the ...
Lei Wang, Kai Xu, Jin Shi
openaire   +1 more source

Null Search for Bursts of Gravitational Radiation

Physical Review Letters, 1973
A calibrated detector of kilohertz-band gravitational radiation has been built which has sufficiently improved sensitivity over Weber's apparatus to allow comparison with his two-detector coincidence results. No events were observed by us at 710 Hz during a recent three-month period of observation.
openaire   +1 more source

Comparison of radiating divertor behaviour in single-null and double-null plasmas in DIII-D

Nuclear Fusion, 2008
‘Puff-and-pump’ radiating divertor scenarios, applied to both upper single-null (SN) and double-null (DN) H-mode plasmas, result in a 30–60% increase in radiated power with little or no decrease in τE. Argon was injected into the private flux region of the upper divertor, and plasma flow into the upper divertor was enhanced by a combination of ...
T.W. Petrie, N.H. Brooks, M.E. Fenstermacher, M. Groth, A.W. Hyatt, R.C. Isler, C.J. Lasnier, A.W. Leonard, G.D. Porter, M.J. Schaffer, J.G. Watkins, M.R. Wade, W.P. West   +12 more
openaire   +1 more source

A Filtering Patch Antenna With Flexibly Controllable Radiation Nulls

2022
In this paper, a filtering patch antenna with flexibly controllable radiation nulls is presented. The patch antenna is fed by an F-shaped probe consisting of two arms along the Y-axis and a metal column along the Z-axis. A broadside radiation null on the lower band is generated by cross-coupling.
jingwei Ma, Yi Zhang, Dongfang zhou, Dalong Lv   +3 more
openaire   +1 more source

Null-plane quantum electrodynamics in an external radiation field

Canadian Journal of Physics, 1976
The formalism developed in this paper is designed to treat the interaction of an electron with a laser pulse. Precisely, it is a formulation on null hyperplanes of quantum electrodynamics in an external radiation field.The result is a quantum electrodynamic formulation in which one works in the Furry picture.
openaire   +2 more sources

Design of Filtering-Radiating Patch Antennas With Tunable Radiation Nulls for High Selectivity

IEEE Transactions on Antennas and Propagation, 2018
This communication demonstrates a method to design filtering antennas by using the filtering-radiating patch (FRP). The so-called FRP is a structure of a rectangular patch etched with slots. It inherits the radiation performance of conventional patch antennas, and more importantly, introduces filtering feature with a radiation null at either the upper ...
Jun Ye Jin, Shaowei Liao, Quan Xue
openaire   +1 more source

Gravitational radiation near spatial and null infinity

Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences, 1987
Abstract Taking Bondi’s approach to an extreme by adding a 1/u-expansion to the usual 1/r-expansion, one can study the effects of the presence of mass at space-like infinity. Assuming convergence of the formal expansion one finds: (1) the limit of the Bondi mass agrees with the ADM-mass of certain space-like hypersurfaces; (2 ...
openaire   +1 more source

A null detecting system for absolute measurement of infrared radiation

International Journal of Infrared and Millimeter Waves, 1983
A pyroelectric radiometer is so designed that the output of the detector is null for equivalent radiation and electric powers. The sensing element is comprised of two poled crystal plates joined together such that the polarity of domains reverses across the junction.
M. M. Pradhan, R. K. Garg
openaire   +1 more source