Results 121 to 130 of about 179,532 (301)
Reduction of JT8D powered aircraft noise by engine refanning [PDF]
The technical feasibility is described of substantially reducing the noise levels of existing JT8D powered aircraft by retrofitting the existing fleet with quieter refan engines and new acoustically treated nacelles.
Medeiros, A. A., Stitt, L. E.
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Monitoring GPS‐collared moose by ground versus drone approaches: efficiency and disturbance effects
Wildlife Biology, EarlyView.Efficient wildlife management requires precise monitoring methods, for example to estimate population density, reproductive success, and survival. Here, we compared the efficiency of drone (equipped with a RGB camera) and ground approaches to detect and observe GPS‐collared female moose Alces alces and their calves. We also quantified how drone (n = 42)
Martin Mayer +8 more
wiley +1 more source
Aircraft Noise Reduction Strategies and Analysis of the Effects. [PDF]
Int J Environ Res Public Health, 2023 Xie J, Zhu L, Lee HM.
europepmc +1 more source
Aircraft noise synthesis system: Version 4 user instructions [PDF]
A modified version of the Aircraft Noise Synthesis System with improved directivity and tonal content modeling has been developed. The synthesis system is used to provide test stimuli for studies of community annoyance to aircraft flyover noise.
Grandle, Robert E. +2 more
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Human response to aircraft noise [PDF]
, 1991 The human auditory system and the perception of sound are discussed. The major concentration is on the annnoyance response and methods for relating the physical characteristics of sound to those psychosociological attributes associated with human ...
Fields, James M., Powell, Clemans A.
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Wildlife Biology, EarlyView.Resource managers require accurate estimates of large herbivore abundance and demography to maintain ecological integrity. Common methods to count these species, including observations from low altitude helicopter flights, may conflict with other protected area management objectives and struggle to produce precise estimates for more cryptic species. To
Hanem G. Abouelezz, N. Thompson Hobbs
wiley +1 more source
Interior noise levels of two propeller-driven light aircraft [PDF]
The relationships between aircraft operating conditions and interior noise and the degree to which ground testing can be used in lieu of flight testing for performing interior noise research were studied.
Catherines, J. J., Mayes, W. H.
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Monitoring wildlife using long‐endurance solar‐electric UAVs
Wildlife Biology, EarlyView.This report discusses the effectiveness of using small solar‐electric UAV (uncrewed aerial vehicles) for aerial wildlife monitoring. We review four years of aerial wildlife monitoring missions using a 5.5‐m wingspan, solar‐electric UAV that was equipped with a gimballed IR/RGB camera.
Götz Bramesfeld +3 more
wiley +1 more source
A Quiet Helicopter for Air Taxi Operations [PDF]
NASA is exploring rotorcraft designs for VTOL air taxi operations, also known as urban air mobility (UAM) or on-demand mobility (ODM) applications. Several concept vehicles have been developed, intended to focus and guide NASA research activities in ...
Johnson, Wayne
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Wildlife Biology, EarlyView.Urban green spaces experience a mix of natural and anthropogenic noises, which could disrupt the vocal communication of several species. This study investigated how such complex soundscapes affect the occurrence of Anaxipha pallidula, which communicates through calls, focusing on both sound level and quality.
Hiroki Mori, Takeshi Osawa
wiley +1 more source