Results 251 to 260 of about 84,293 (284)

Bonding of grouted eccentric strands in duct at elevated temperatures

Proceedings of the 11th International Conference on Structures in Fire (SiF2020), 2020
Prestressing strands are often located eccentrically within ducts in post-tensioned structures due to curvature of profile. To investigate the bond performance of grouted tendons, pull-out tests are conducted on mono- and multi-strand tendons located eccentrically in grouted ducts in concrete at temperatures of 20°C to 600°C.
Wu, Xiqiang, Au, Francis Tat Kwong, Huang, Xinyan   +2 more
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Elevated duct propagation in the tradewinds

IRE Transactions on Antennas and Propagation, 1961
All of the maximum propagation (220 Mc) ranges observed in an elevated duct regime varied from 500 to 1200 miles compared to less than 400 miles observed with the same equipment elsewhere. The measurements were made at the optimum season (November) in a tradewind regime between Brazil and Ascension Island ( 8\deg S. latitude). The field strengths above
D. Ringwalt, F. Macdonald
openaire   +1 more source

Attenuation of Sound in Wide Ducts with Flow at Elevated Pressure and Temperature

19th AIAA/CEAS Aeroacoustics Conference, 2013
Abstract At ambient conditions the acoustic losses within the fluid are two orders of magnitude smaller than those occurring at a duct wall, so that they are commonly neglected in duct acoustics. Recent measurements revealed an increasing sound attenuation at elevated pressure and temperature, which cannot be justified by the viscothermal losses at ...
Lahiri, Claus, Knobloch, Karsten, Bake, Friedrich, Enghardt, Lars   +3 more
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Propagation through an elevated duct: Tradewinds III

IEEE Transactions on Antennas and Propagation, 1964
In July and August of 1960, a joint Naval Research Laboratory-Naval Electronics Laboratory radio-meteorological program (Project Tradewinds III) was carried out between San Diego, Calif., and Opana, Hawaii. The purpose of this project was to evaluate the propagation characteristics of the duct formed by the tradewinds inversion which is generally found
N. Guinard, J. Ransone, D. Randall, C. Purves, P. Watkins   +4 more
openaire   +1 more source

On the short-term time evolution of elevated ducting layers

2012 Loughborough Antennas & Propagation Conference (LAPC), 2012
Vertical profiles of atmospheric refractivity are obtained from the tower measurement of temperature and humidity profiles with a vertical resolution less than eight meters and a time resolution one minute. Profiles are described using a modified Webster model with model parameters fitted by nonlinear regression.
Martin Grabner, Vaclav Kvicera, Pavel Pechac, Otakar Jicha   +3 more
openaire   +1 more source

Elevated Gastrin Levels After Pancreatic Duct Ligation

Archives of Surgery, 1973
To the Editor .—I am writing to discuss the article in theArchivesentitled "Elevated Gastrin Levels After Pancreatic Duct Ligation" by Basso et al (105:611, 1972). The authors conclude in the summary and also on page 614 that, "Inhibition of acid secretion by fat was relatively as efficient following as before pancreatic duct ligation." This ...
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Radar detection of missile plumes embedded in elevated atmospheric ducts

1996 IEEE Aerospace Applications Conference. Proceedings, 2002
An elevated atmospheric duct results when the refractive index profile of the atmosphere increases then decreases with altitude. Propagation of electromagnetic waves close to the horizontal is similar to propagation in a parallel plate waveguide, effectively increasing detection range.
J.J. Acree, M.W. Maier
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Ducted Fan Effect on the Elevation of a Concept Helicopter When the Ducted Faintail Is Located in a Ground Effect Region

Journal of Aerospace Engineering, 2016
AbstractIn this study, the effect of the ducted fan, which is located inside the ground effect region, is investigated experimentally according to the helicopter hovering concept. For this investigation, the thrust of the ducted fan is measured using two different experimental methods. In the first method, the static pressure measurement system is used
M. H. Doğru, İ. H. Güzelbey, İbrahim Göv   +2 more
openaire   +1 more source

The mechanism of elevated alkaline phosphatase activity after bile duct ligation in the rat

Hepatology, 1986
Alkaline phosphatase activity in the liver and intestine increases after bile duct ligation, reportedly by increased enzyme synthesis. To ascertain the mechanism of this increased synthesis in the absence of a cDNA clone encoding the enzyme, we have estimated the concentration of liver and intestinal alkaline phosphatase mRNA ...
S, Seetharam, N L, Sussman, T, Komoda, D H, Alpers   +3 more
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Investigations into the occurrence of elevated ducts in lower atmosphere near Arabian Sea

2015 International Conference on Space Science and Communication (IconSpace), 2015
Radio signals can dramatically change their propagation behavior while passing through the atmosphere. Radio signals can get trapped in ducting layers and can travel long distances without much loss. This can be both advantageous and adverse; former in a sense that signal can travel beyond horizon, and latter in sense that it can interfere with a ...
Asad Ullah, Saeed Ur Rehman, Naveed Mufti   +2 more
openaire   +1 more source