scholarly journals Neutron capture studies with a short flight path

2010 ◽  
Author(s):  
Stephan Walter ◽  
Michael Heil ◽  
Franz Käppeler ◽  
Ralf Plag ◽  
Rene Reifarth
Keyword(s):  
Neutron Capture ◽  
Flight Path ◽  
Short Flight

Spallation Neutron Measurement by the Time-of-Flight Method with a Short Flight Path

1995 ◽  
Vol 32 (9) ◽  
pp. 827-833 ◽  
Author(s):  
Tatsushi NAKAMOTO ◽  
Kenji ISHIBASHI ◽  
Naruhiro MATSUFUJI ◽  
Nobuhiro SHIGYO ◽  
Keisuke MAEHATA ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Flight Path ◽  
Neutron Measurement ◽  
Time Of Flight Method ◽  
Short Flight

Ground state photoneutron angular distributions in the giant resonance of 16O

1970 ◽  
Vol 48 (14) ◽  
pp. 1635-1648 ◽  
Author(s):  
J. W. Jury ◽  
J. S. Hewitt ◽  
K. G. McNeill
Keyword(s):  
Cross Section ◽  
Ground State ◽  
Giant Resonance ◽  
Flight Path ◽  
Angular Distributions ◽  
Interference Effects ◽  
Experimental Runs ◽  
High Neutron ◽  
High Neutron Energy ◽  
Short Flight

Photoneutron spectra for transitions to the ground state in the giant resonance of 16O were measured with high neutron energy resolution (ΔE ~ 60 keV) at angles of 50, 66, 82, 98, 114, 130, and 146 degrees relative to the direction of the incident bremsstrahlung beam. The spectra at the various angles were measured during successive experimental runs using a single 50 m time-of-flight spectrometer. The different angles were obtained by bending the electron beam relative to the direction of the flight path. Angular normalization was achieved by using a fast neutron monitor located at the end of a short flight path which was always normal to the reaction plane. Legendre coefficients for the angular distributions were extracted as functions of the excitation energy. From the energy dependence of the coefficients, interference effects are evident in the ground state (γ,n) cross section in the region from 17 to 30 MeV.

scholarly journals Unpredictable hummingbirds: Flight path entropy is constrained by speed and wing loading

2020 ◽  
Author(s):  
Ilias Berberi ◽  
Paolo S. Segre ◽  
Douglas L. Altshuler ◽  
Roslyn Dakin
Keyword(s):  
Information Theory ◽  
Flight Path ◽  
Escape Performance ◽  
Wing Loading ◽  
Trade Off ◽  
Underlying Basis ◽  
Varying Environments ◽  
Short Flight

ABSTRACTUnpredictable movement can provide an advantage when animals avoid predators and other threats. Previous studies have examined how varying environments can elicit unpredictable movement, but the intrinsic causes of complex, unpredictable behavior are not yet known. We addressed this question by analyzing >200 hours of flight performed by hummingbirds, a group of aerial specialists noted for their extreme agility and escape performance. We used information theory to calculate unpredictability based on the positional entropy of short flight sequences during 30-min and 2-hour trials. We show that a bird’s entropy is repeatable, with stable differences among individuals that are negatively correlated with wing loading: birds with lower wing loading are less predictable. Unpredictability is also positively correlated with a bird’s overall acceleration and rotational performance, and yet we find that moment-to-moment changes in acceleration and rotational velocities do not directly influence entropy. This indicates that biomechanical performance must share an underlying basis with a bird’s ability to combine maneuvers into unpredictable sequences. Contrary to expectations, hummingbirds achieve their highest entropy at relatively slow speeds, pointing to a fundamental trade-off whereby individuals must choose to be either fast or unpredictable.

Cognitive Factors Mediate the Relation Between Age and Flight Path Maintenance in General Aviation

2016 ◽  
Vol 6 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Kathleen Van Benthem ◽  
Chris M. Herdman
Keyword(s):  
Cognitive Functioning ◽  
Flight Path ◽  
General Aviation ◽  
Cognitive Factors ◽  
Pilot Performance ◽  
Pilot Error ◽  
Age Related ◽  
And Performance ◽  
Relationship Of ◽  
The Relationship

Abstract. Identifying pilot attributes associated with risk is important, especially in general aviation where pilot error is implicated in most accidents. This research examined the relationship of pilot age, expertise, and cognitive functioning to deviations from an ideal circuit trajectory. In all, 54 pilots, of varying age, flew a Cessna 172 simulator. Cognitive measures were obtained using the CogScreen-AE ( Kay, 1995 ). Older age and lower levels of expertise and cognitive functioning were associated with significantly greater flight path deviations. The relationship between age and performance was fully mediated by a cluster of cognitive factors: speed and working memory, visual attention, and cognitive flexibility. These findings add to the literature showing that age-related changes in cognition may impact pilot performance.

SIMULATION OF THE FLIGHT OF A DROP OF GALVANIC ELECTROLYTE IN AN INHOMOGENEOUS FIELD OF AN ELECTRIC CATCHER

2020 ◽  
Author(s):  
V.I. Garshin ◽  
◽  
A.R. Lebedev ◽  
S.E. Geraskova ◽  
◽  
...  
Keyword(s):  
Electric Field ◽  
Flight Path ◽  
Inhomogeneous Field ◽  
Inhomogeneous Electric Field ◽  
Trajectory Method

The article shows the relations for modeling an inhomogeneous electric field and the flight path of a drop of galvanic electrolyte in it. Estimates are preliminary. Articles and patents of authors in which non-uniform fields are already used are given. A modified trajectory method is proposed for evaluating the effectiveness of trapping harmful electrolyte droplets.

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