2,381,146 research outputs found
Time Resolved Two Dimensional X-Ray Densitometry of a Two Phase Flow Downstream of a Ventilated Cavity
Full text linkTo measure the void fraction distribution in gas-liquid flows, a two-dimensional x-ray densitometry system was developed. This system is capable of acquiring a two-dimensional projection with a 225 cm2 area of measurement through 21 cm of water. The images can be acquired at rates on the order of 1 kHz. Common sources of error in x-ray imaging, such as x-ray scatter, image distortion, veiling glare, and beam hardening were considered, and mitigated. The measured average void fraction was compared success fully to that of a phantom target and found to be within 1%. To evaluate the performance of the new system, the flow in and downstream of a ventilated nominally two-dimensional partial cavity was investigated and compared to measurements from dual tip fiber optical probes and high speed video. The measurements were found to have satisfactory agreement for void fractions above 5% of the selected void fraction measurement range.Office of Naval Research under grant N00014-10-1-097
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Ray A. Robinson Vietnam War collection [DIGITAL CONTENT]
No full textThis collection contains an oral history interview with Ray A. Robinson from May 9, 2016, as well as documents and photographs related to his life and to his military service
Bullfrog Rapids. (Lee Malin telling Ray Bramble to sit down.)
No full textPhoto of SOCOTWA boaters at Bullfrog Rapids on the Colorado River, during a river trip through Glen Canyon in July of 1954. Taken by participant Ray Bramble
[Letters from Ray A. Gano and Douglas G. Gray - 1976]
No full textLetter from Ray A. Gano to Douglas G. Gray regarding Arizona LULAC financial information. The letter also includes a note from Ray A. Gano to Douglas G. Gray on December 1, 1976, requesting copies of cancelled LULAC National checks signed by Joseph R. Benites in 1974
[Envelope from Ray A. Gano to John J. Herrera - June 7, 1979]
No full textEnvelope postmarked June 7, 1979, addressed to John J. Herrera on printed stationary of the League of United Latin American Citizens letterhead from Ray A. Gano, LULAC National Vice President
Experimental Measurements and Computer Simulation of Fission Product Gamma-Ray Spectra
Full text linkAirborne gamma ray spectrometry using high volume scintillation detectors, optionally in conjunction with Ge detectors, has potential for making rapid environmental measurements in response to nuclear accidents. An experimental investigation and computer simulation have been used to characterise the response of such detectors to short lived fission products. Small samples of 235U were irradiated in a research reactor for short periods, to generate fission product sources. Gamma ray spectra were recorded over a period of one year using both high volume scintillation detectors and semiconductor detectors. The main gamma emitting nuclides have been identified, and their associated signals in each detector defined. Simulation work has been used to calculate the corresponding spectra which would have been observed at airborne survey heights, or from fission product sources irradiated for a prolonged period. While Ge detectors can record a fuller range of isotopes, of interest in characterising release terms, the NaI spectra also have potential for providing data on a range of radiologically important isotopes at all stages
Ray at St Albans
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/247948171231
Item: [1981.0081.00343] "Ray at St Albans
Ray at Dorking
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/247950171233
Item: [1981.0081.00345] "Ray at Dorking
Ray at Richmond Park
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/247954171237
Item: [1981.0081.00349] "Ray at Richmond Park
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