Results 81 to 90 of about 44,118 (256)

The cost of applying current helicopter external noise reduction methods while maintaining realistic vehicle performance [PDF]

Analytical methods were developed and/or adopted for calculating helicopter component noise, and these methods were incorporated into a unified total vehicle noise calculation model.
Bowes, M. A.
core   +1 more source

Assessment of the Feasibility of an Extended Range Helicopter Operational Standard for Offshore Flights [PDF]

, 2018
The accident rate of rotorcraft has improved signi1cantly over the years but at a slow pace, and in any case the number of accidents per 2ight hours is one or two orders of magnitude higher than that of commercial aircraft, a consideration that could ...
Barakos, George, Ezgi, Akel, Fasiello, Simone, Friesen, Daniel, Ghiasvand, Sara, Huercas, Sergio, Masarati, Pierangelo, Morelli, Myles, Nabi, Hafiz Noor, Pavel, Marilena, Quaranta, Giuseppe, Scaramuzzino, Paolo Francesco, Taymourtash, Neda, White, Mark, Ying, Yu   +14 more
core  

Rapid increase in abundance and distribution of invasive pink salmon (Oncorhynchus gorbuscha) within a diverse, large Barents Sea catchment

Journal of Fish Biology, EarlyView.
Abstract Pink salmon originate from the North Pacific area but were introduced into northwest Russia from the late 1950s onwards. Since 2017, the alien species has increased dramatically in abundance and rapidly invaded adjacent areas of the North Atlantic region.
Jaakko Erkinaro, Panu Orell, Frode Fossøy, Mikko Kytökorpi, Karl Gjelland, Narve Johansen, Sigurd Domaas, Jorma Kuusela, Pierre Fagard, Eirik Frøiland, Morten Falkegård   +10 more
wiley   +1 more source

Reduction of torque pulsation in ultralight helicopter transmission

Acta Polytechnica
Usually, 1–2 seats helicopters use piston engines. One of their disadvantages is a significant torque pulsation on the engine shaft. The main reason for such fluctuations is the change in parameters during the engine’s operating cycle.
Vitaly Dudnik
doaj   +1 more source

Results of the flight noise measurement program using a standard and modified SH-3A helicopter [PDF]

A field noise measurement program has been conducted using both a standard SH-3A helicopter and an SH-3A helicopter modified to reduce external noise levels.
Henderson, H. R., Hilton, D. A., Pegg, R. J.   +2 more
core   +1 more source

NASA helicopter transmission system technology program [PDF]

, 1983
The purpose of the NASA Helicopter Transmission System Technology Program is to improve specific mechanical components and the technology for combining these into advanced drive systems to make helicopters more viable and cost competitive for commerical ...
Zaretsky, E. V.
core   +1 more source

Banking with Inside Money: An Efficiency Analysis

Journal of Money, Credit and Banking, EarlyView.
Abstract We show that banks do not decentralize the first best in a nominal Diamond–Dybvig economy with inside money. Furthermore, state‐contingent deposit contracts do not expand the consumption possibility set to include the first best either. Central banks can improve welfare but only for savers and only with unconventional monetary policy. Finally,
DAVID RIVERO, HUGO RODRÍGUEZ MENDIZÁBAL   +1 more
wiley   +1 more source

HELICOPTER PROPULSION SYSTEM

Journal of Industrial Design and Engineering Graphics, 2012
The objective of this paper is to understand how a helicopter jet engine works, which are their main characteristics and how they can be improved.
IONESCU Cristian Andrei
doaj  

Method for Helicopter Turboshaft Engines Controlling Energy Characteristics Through Regulating Free Turbine Rotor Speed and Fuel Consumption Based on Neural Networks

Energies
This research is devoted to the development of a method for helicopter turboshaft engine energy characteristics control by regulating the free turbine rotor speed and fuel consumption using neural network technologies.
Serhii Vladov, Maryna Bulakh, Jan Czyżewski, Oleksii Lytvynov, Victoria Vysotska, Victor Vasylenko   +5 more
doaj   +1 more source

A summary of rotorcraft handling qualities research at NASA Ames Research Center [PDF]

, 1984
The objectives of the rotorcraft handling qualities research program at Ames Research Center are twofold: (1) to develop basic handling qualities design criteria to permit cost effective design decisions to be made for helicopters, and (2) to obtain ...
Chen, R. T.
core   +1 more source