Results 131 to 140 of about 232,137 (308)

Sketch of the Configuration Scheme of Two-stage Variable Speed Gear Transmission in Unmanned Helicopter Main Gearbox

open access: yesJixie chuandong, 2018
For unmanned helicopter economic cruises,main rotor speed changes could be significant. At present,the most effective method of changing the main rotor speed associated with the great speed range and low cost is a variable speed gear transmission ...
Li Zhengminqing   +4 more
doaj  

Performance Data from a Wind-Tunnel Test of Two Main-rotor Blade Designs for a Utility-Class Helicopter [PDF]

open access: yes
An investigation was conducted in the NASA Langley Transonic Dynamics Tunnel to evaluate an advanced main rotor designed for use on a utility class helicopter, specifically the U.S. Army UH-60A Blackhawk.
Singleton, Jeffrey D.   +2 more
core   +1 more source

A compatibility criterion for optimal control and information aggregation in hierarchical network systems

open access: yesAsian Journal of Control, EarlyView.
Abstract Large swarms often adopt a hierarchical network structure that incorporates information aggregation. Although this approach offers significant advantages in terms of communication efficiency and computational complexity, it can also lead to degradation due to information constraints.
Kento Fujita, Daisuke Tsubakino
wiley   +1 more source

Study on dynamic characteristics of the helicopter main transmission system

open access: yesJixie chuandong
ObjectiveTo identify the main excitation frequencies that cause the vibration of the helicopter main transmission system and reveal the influence of system speed, rotor torque, and rotor lift on the dynamic characteristics of the helicopter main ...
XU Huachao   +5 more
doaj  

Experimental study of main rotor tip geometry and tail rotor interactions in hover. Volume 1. Text and figures [PDF]

open access: yes
A model scale hover test was conducted in the Sikorsky Aircraft Model rotor hover Facility to identify and quantify the impact of the tail rotor on the demonstrated advantages of advanced geometry tip configurations.
Balch, D. T., Lombardi, J.
core   +1 more source

Manoeuvrability assessment of a hybrid compound helicopter configuration [PDF]

open access: yes, 2014
The compound helicopter design could potentially satisfy the new emerging requirements placed on the next generation of rotorcraft. The main benefit of the compound helicopter is its ability to reach speeds that significantly surpass the conventional ...
Ferguson, Kevin, Thomson, Douglas
core  

Impact of Process Interruptions in the Production of Lysates for Cell‐Free Expression Systems

open access: yesBiotechnology and Bioengineering, EarlyView.
ABSTRACT Cell‐free gene expression systems offer cell‐like functionalities outside the confines of the cell, garnering increasing interest for applications from biomanufacturing to sensing. As applications expand, the need to implement economically scaled processes to produce cellular lysates grows.
Katherine A. Rhea   +11 more
wiley   +1 more source

Force stimulation promotes nerve regeneration by restoring cellular energy

open access: yesBMEMat, EarlyView.
Mechanical stimulation can help nerves regenerate in various ways. We developed two devices (a piezo‐motor‐driven stretching device and a SAW‐based actuator) to apply mechanical stimulation to sciatic nerve and DRG neurons. Our study shows that appropriate mechanical force stimulation can promote regeneration by restoring the energy supply to the ...
Zhe Wang   +10 more
wiley   +1 more source

The Investigation of the Deactivation of the Metal‐Modified ZSM‐5 Zeolites for the Catalytic Dehydration of Glycerol

open access: yesCarbon and Hydrogen, EarlyView.
During the glycerol dehydration over ZSM‐5 zeolite, the modification by metal promoters results in the suppression of the bicyclic and tricyclic aromatics over the modified ZSM‐5 zeolite catalysts. However, the issue of the fast deactivation still remains an apparent challenge, which requires more different perspectives to understand the deactivation ...
Yonghua Yu   +7 more
wiley   +1 more source

Model helicopter rotor high-speed impulsive noise: Measured acoustics and blade pressures [PDF]

open access: yes
A 1/17-scale research model of the AH-1 series helicopter main rotor was tested. Model-rotor acoustic and simultaneous blade pressure data were recorded at high speeds where full-scale helicopter high-speed impulsive noise levels are known to be dominant.
Boxwell, D. A.   +3 more
core   +1 more source

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