833 research outputs found
Thrust-induced effects on subsonic longitudinal aerodynamic characteristics of a vectored-engine-over-wing configuration
An investigation was conducted in the Langley 4 by 7 Meter Tunnel of the thrust induced effects on the longitudinal aerodynamic characteristics of a vectored-engine-over-wing fighter aircraft. The investigation was conducted at Mach numbers from 0.14 to 0.17 over an angle-of-attack range from -2 deg to 26 deg. The major model variables were the spanwise blowing nozzle sweep angle and main nozzle vector angle along with trailing edge, flap deflections. The overall thrust coefficient (main and spanwise nozzles) was varied from 0 (jet off) to 2.0. The results indicate that the thrust-induced effects from the main nozzle alone were small and mainly due to boundary-layer control affecting a small area behind the nozzle. When the spanwise blowing nozzles were included, the induced effects were larger than the main nozzle alone and were due to both boundary layer control and induced circulation lift. No leading edge vortex effects were evident
Renormalization Group Improvement and Dynamical Breaking of Symmetry in a Supersymmetric Chern-Simons-matter Model
In this work, we investigate the consequences of the Renormalization Group
Equation (RGE) in the determination of the effective superpotential and the
study of Dynamical Symmetry Breaking (DSB) in an N = 1 supersymmetric theory
including an Abelian Chern-Simons superfield coupled to N scalar superfields in
(2+1) dimensional spacetime. The classical Lagrangian presents scale
invariance, which is broken by radiative corrections to the effective
superpotential. We calculate the effective superpotential up to two-loops by
using the RGE and the beta functions and anomalous dimensions known in the
literature. We then show how the RGE can be used to improve this calculation,
by summing up properly defined series of leading logs (LL), next-to-leading
logs (NLL) contributions, and so on... We conclude that even if the RGE
improvement procedure can indeed be applied in a supersymmetric model, the
effects of the consideration of the RGE are not so dramatic as it happens in
the non-supersymmetric case.Comment: v4: 11 pages, 1 figure. Version accepted for publication in NP
Investigation of trailing-edge-flap, spanwise-blowing concepts on an advanced fighter configuration
The aerodynamic effects of spanwise blowing on the trailing edge flap of an advanced fighter aircraft configuration were determined in the 4 by 7 Meter Tunnel. A series of tests were conducted with variations in spanwise-blowing vector angle, nozzle exit area, nozzle location, thrust coefficient, and flap deflection in order to determine a superior configuration for both an underwing cascade concept and an overwing port concept. This screening phase of the testing was conducted at a nominal approach angle of attack from 12 deg to 16 deg; and then the superior configurations were tested over a more complete angle of attack range from 0 deg to 20 deg at tunnel free stream dynamic pressures from 20 to 40 lbf/sq ft at thrust coefficients from 0 to 2
Thrust-induced effects on low-speed aerodynamics of fighter aircraft
Results of NASA Langley has conducted wind-tunnel investigations of several fighter configurations conducted to determine the effects of both thrust vectoring and spanwise blowing are reviewed. A recent joint NASA/Grumman Aerospace Corporation/U.S. Air Force Wright Aeronautical Laboratory wind-tunnel investigation was conducted to examine the effects of spanwise blowing on the trailing-edge flap system. This application contrasts with the more familiar method of spanwise blowing near the wing leading edge. Another joint program among NASA/McDonnell Aircraft Company/U.S. Air Force Wright Aeronautical Laboratory investigated the effects of reverse thrust on the low-speed aerodynamics of an F-15 configuration. The F-15 model was fitted with a rotating van thrust reverser concept which could simulate both in-flight reversing for approach and landing or full reversing for ground roll reduction. The significant results of these two joint programs are reported
Non-perturbative fixed points and renormalization group improved effective potential
The stability conditions of a renormalization group improved effective
potential have been discussed in the case of scalar QED and QCD with a
colorless scalar. We calculate the same potential in these models assuming the
existence of non-perturbative fixed points associated to a conformal phase. In
the case of scalar QED the barrier of instability found previously is barely
displaced as we approach the fixed point, and in the case of QCD with a
colorless scalar not only the barrier is changed but the local minimum of the
potential is also changed.Comment: 6 pages, 8 figures, References added. Matching the journal versio
A disposable amperometric biosensor for rapid screening of anticholinesterase activity in soil extracts
A disposable amperometric biosensor for the determination
of anticholinesterase activity in soil extracts is described.
The sensitive membrane was obtained by co-crosslinking
acetylcholinesterase and choline oxidase with bovine serum
albumin using glutaraldehyde. The anticholinesterase activity
of the soil extract was measured using chronoamperometry
at 650 mV vs. Ag/AgCl to monitor the biocatalytically
produced H2O2 before and after the inhibition step. An
inhibition percentage of 38 ± 4% was recorded for soil
extracts spiked with 10 ppb of ethyl parathion. The device
has the potential to be used as a gross sensor for the
assessment of anticholinesterase activity in soil extracts
Assessment of the radiological impact of a decommissioning nuclear power plant in Italy
The assessment of the radiological impact of a decommissioning Nuclear Power
Plant is presented here through the results of an environmental monitoring
survey carried out in the area surrounding the Garigliano Power Plant. The
levels of radioactivity in soil, water, air and other environmental matrices
are shown, in which {\alpha}, {\beta} and {\gamma} activity and {\gamma}
equivalent dose rate are measured. Radioactivity levels of the samples from the
Garigliano area are analyzed and then compared to those from a control zone
situated more than 100 km away. Moreover, a comparison is made with a previous
survey held in 2001. The analyses and comparisons show no significant
alteration in the radiological characteristics of the area surroundings the
plant, with an overall radioactivity depending mainly from the global fallout
and natural sources.Comment: 13 pages, 6 figures, 2 table
Assessment of the radiological impact of a decommissioning nuclear power plant in Italy
The assessment of the radiological impact of a decommissioning Nuclear Power
Plant is presented here through the results of an environmental monitoring
survey carried out in the area surrounding the Garigliano Power Plant. The
levels of radioactivity in soil, water, air and other environmental matrices
are shown, in which {\alpha}, {\beta} and {\gamma} activity and {\gamma}
equivalent dose rate are measured. Radioactivity levels of the samples from the
Garigliano area are analyzed and then compared to those from a control zone
situated more than 100 km away. Moreover, a comparison is made with a previous
survey held in 2001. The analyses and comparisons show no significant
alteration in the radiological characteristics of the area surroundings the
plant, with an overall radioactivity depending mainly from the global fallout
and natural sources
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