Institution
Defence Research Agency
About: Defence Research Agency is a based out in . It is known for research contribution in the topics: Synthetic aperture radar & Radar. The organization has 1211 authors who have published 1109 publications receiving 31542 citations.
Topics: Synthetic aperture radar, Radar, Silicon, Radar imaging, Alloy
Papers published on a yearly basis
Papers
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TL;DR: The differential temporal and intensity characteristics of the thermal emission signal from the heated surface coating, resulting from the differential heat deposition profile for on- and off-resonance excitation, are shown to be useful for the purposes of identifying different surface contaminants.
Abstract: We experimentally and theoretically studied the phenomenon of thermal emission from nonvolatile liquid surface coatings following heating with a pulsed CO2 laser. The effects of thermal diffusion across the liquid–air and liquid–substrate interfaces as well as the full absorption spectrum of the liquid are addressed theoretically. The differential temporal and intensity characteristics of the thermal emission signal from the heated surface coating, resulting from the differential heat deposition profile for on- and off-resonance excitation, are shown to be useful for the purposes of identifying different surface contaminants. The application of this technique to standoff thermal imaging of contaminated surfaces is discussed.
7 citations
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TL;DR: In this paper, the network structures formed when the diglycidyl ether of bisphenol A is cured with two stoichiometries of diaminodiphenyl sulfone have been studied by solid-state 13 C n.m.
7 citations
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01 Aug 1995TL;DR: In this paper, the authors present results from the Shuttle Activation Monitor flown in the Space Shuttle middeck area on two missions during August 1989 and September 1991, where the effects of shielding by the spacecraft structure were investigated.
Abstract: Accurate knowledge of the sources of detector background is essential in /spl gamma/-ray astronomy for correct data interpretation, and for optimising detector design and operation. In the low-to medium-energy range, a major source of background arises from radioactivity that is induced in the detector medium itself by nuclear spallation and neutron capture. Results are presented from the Shuttle Activation Monitor flown in the Space Shuttle middeck area on two missions during August 1989 and September 1991. This experiment has been valuable in the study of induced radioactivity in BGO scintillators resulting from bombardment by cosmic-rays, trapped protons, and their secondaries created by interactions in a heavy spacecraft. Data from mono-energetic proton irradiation experiments have allowed investigation of activation effects in BGO for less complicated irradiation conditions, and the results from these experiments are also presented. Detailed simulations have been performed to determine BGO detector activation and response, and these take into consideration the effects of shielding by the spacecraft structure. The results compare very well to the experimental data, allowing features in the measured spectra to be identified. They also highlight the importance of shielding both in reducing activation by trapped protons, and enhancing cosmic-ray induced activation due to secondaries. >
7 citations
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TL;DR: The nature of the fragmentation event is found to significantly affect the additional collision risk to the constellation above the ‘background’ level and thus govern the possible occurrence of a catastrophic breakup chain reaction.
7 citations
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TL;DR: In this article, the authors used light emitting diodes (LEDs) to study the recombination dynamics of minority electrons in p type InAs and derived an upper limit of∼2.1×10 −28 cm 6 s −1 for the total Auger recombination rate constant in 2×10 cm −3 p type material.
Abstract: In this paper, light emitting diodes (LEDs) are used to study the recombination dynamics of minority electrons in p type InAs. The LEDs operate through injecting electrons into p type material with a free surface. When surface recombination is dominant, the output of the LEDs is shown to depend only on the strength of the radiative recombination and not on its efficiency. When surface recombination is not dominant, the dependence of the LED efficiency on the thickness of the active layer is analysed to give the minority carrier diffusion lengths and recombination efficiencies. the electron diffusion lenSgth is shown to be 3±0.5 μm in 5×10 −18 cm −3 p type InAs and 6±1 pm in 2×10 cm −3 p type material. An upper limit of∼2.1×10 −28 cm 6 s −1 is deduced for the total Auger recombination rate constant in p type material.
7 citations
Authors
Showing all 1211 results
Name | H-index | Papers | Citations |
---|---|---|---|
Stephen M. Smith | 128 | 501 | 140104 |
Jonathan Knight | 88 | 625 | 37720 |
M. S. Skolnick | 73 | 728 | 22112 |
Alan Tennant | 70 | 433 | 16870 |
Richard J. Needs | 69 | 352 | 19528 |
Dan S. Henningson | 66 | 369 | 19038 |
John Rarity | 65 | 434 | 15562 |
Michael J. Uren | 44 | 294 | 8408 |
Leigh T. Canham | 42 | 160 | 18268 |
A. G. Cullis | 40 | 161 | 11320 |
Richard A. Pethrick | 38 | 410 | 6918 |
David S. Lee | 38 | 113 | 8580 |
Neil Gordon | 37 | 181 | 37011 |
Pierfrancesco Lombardo | 36 | 301 | 5018 |
Peter John Roberts | 31 | 86 | 6679 |