Results 41 to 50 of about 69,343 (215)

A simulation model for the electrical rotary-wing aircraft (eVTOL) performance estimation for the urban air mobility purposes

Научный вестник МГТУ ГА, 2023
The present paper presents a simulation model description developed for the aircraft performance estimation of the most popular electric vertical takeoff and landing aircraft (eVTOL) aerodynamic configurations with the electric (hybrid) power plant for ...
M. I. Myasnikov, I. R. Ilyin
doaj   +1 more source

Experimental and field evidence indicate that islet‐nesting tundra birds experience reduced nest predation and benefit indirectly from high snow goose densities

Oikos, EarlyView.
Landscape features can shape the occurrence and strength of predator–prey interactions by influencing predation risk and prey distribution. In the High Arctic, some bird species select nesting sites with physical features that impede access for their main terrestrial predator, the Arctic fox.
Marylou Beaudoin, Andréanne Beardsell, Éliane Duchesne, Madeleine‐Zoé Corbeil‐Robitaille, Pierre Legagneux, Dominique Berteaux, Joël Bêty   +6 more
wiley   +1 more source

Control Strategy for Powered Flight Following Tail Rotor Failure in Helicopters

Machines
Tail rotor failure represents a critical emergency in helicopter flight operations. Conventional recovery mandates an immediate engine shutdown and transition to autorotation, significantly compromising both mission survivability and operational ...
Xinming Feng, Haiming Tian, Rui Zu, Yi Luo, Jianbo Li   +4 more
doaj   +1 more source

Combined Machining of Ti-6Al-4V Alloy Using Electrochemical Milling and Electrochemical Grinding

International Journal of Electrochemical Science, 2019
Ti-6Al-4V is a typical difficult-to-cut material with which it is difficult to achieve a high processing efficiency and good surface quality simultaneously using a single processing method.
Gangqiang Liu, Hansong Li, Shen Niu, Xiaokang Yue, Ningsong Qu   +4 more
doaj   +1 more source

Exploring consumer preferences for wild meat and other animal proteins in Gamba, Gabon: Implications for conservation and management of natural resources alongside extractive industry

People and Nature, EarlyView.
Abstract The town of Gamba in southwest Gabon represents an exceptional example of how the development of an extractive industry (in this case oil production) may impact wild meat consumption in an area of global importance for biodiversity. Studies in the 1990s identified an active wild meat trade; however, no studies have been undertaken since, and ...
James McNamara, Landry Tchignoumba, Gabriel Koumba, Ghislain Guissouegou, Anna Feistner   +4 more
wiley   +1 more source

Helicopter brownout - can it be modelled? [PDF]

, 2010
Significant progress has been made to date in modelling, computationally, the formation and development of the dust cloud that forms in the air surrounding the rotorcraft under brownout conditions.
Brown, R.E., Kim, Hyo Wan, Phillips, Catriona, Brown, Richard   +3 more
core   +1 more source

Numerical Analysis of Aerodynamic Performance of Low Tip‑Speed Rotors with Gurney Flaps

Nanjing Hangkong Hangtian Daxue Xuebao
To explore the potential for increasing lift on low tip-speed rotors， a rotor performance calculation model is established. The flight data of the UH-60A helicopter are utilized to validate this model.
WAN Haoyun, HAN Dong, WANG Tianjian
doaj   +1 more source

Evaluating Testability of Permafrost Models Through Physical and Thermal Testing in Complex Mountain Terrain, Yukon, Canada

Permafrost and Periglacial Processes, EarlyView.
ABSTRACT Due to its subsurface nature, permafrost cannot be directly observed with the naked eye or optical remote sensing. Consequently, accurately describing its distribution and thermal state is challenging. This is especially true in vast, remote environments, where obtaining comprehensive field data is demanding or improbable.
Ria Nicholson, Philip P. Bonnaventure, Nick C. Noad, Madeleine C. Garibaldi, Rabecca Thiessen, Will Kochtitzky   +5 more
wiley   +1 more source

Evaluation of ADS-33E Cargo Helicopter Requirements Using a CH-53G [PDF]

, 2006
Flight tests with a Sikorsky CH 53G of the German Federal Armed Forces were conducted in Germany under the U.S./German Memorandum of Understanding (MoU) for Cooperative Research in Helicopter Aeromechanics to evaluate the cargo helicopter requirements of
Blanken, Chris L., Strecker, Gerhard, Höfinger, Marc   +2 more
core  

Internal Structure, Kinematics, and Prehistory of Frozen Debris Lobe‐A (FDL‐A), Brooks Range, Alaska

Permafrost and Periglacial Processes, EarlyView.
ABSTRACT Frozen Debris Lobe‐A (FDL‐A)—one of hundreds of FDLs in the Brooks Range of northern Alaska—is a slow‐moving landslide in permafrost that has been the subject of research since 2008 due to its close proximity to the Dalton Highway. Here, we synthesize more than a decade's worth of climate and surface measurements of monitored FDLs, and the ...
Margaret M. Darrow, Esther L. Babcock, Ben A. Leshchinsky   +2 more
wiley   +1 more source