Results 111 to 120 of about 5,948 (253)
Transmission research activities at NASA Lewis Research Center [PDF]
A joint research program, to advance the technology of rotorcraft transmissions, consists of analytical and experimental efforts to achieve the overall goals of reducing transmission weight and noise, while increasing life and reliability.
Lewicki, D. G.
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Restoration Ecology, EarlyView.Abstract Introduction The European Union (EU) policy framework emphasizes the importance of innovation to achieve the environmental goals and to ensure continued economic growth and increased EU global competitiveness. Objectives This paper analyses whether those policy instruments can effectively support ecosystem restoration.
Sašo Gorjanc +6 more
wiley +1 more source
Jixie chuandongTunnel boring machine (TBM) reducers are important components of TBM's cutter-head drive system. In order to reveal the dynamic characteristics of the two-stage planetary gear transmission system of the TBM reducer, the influence factors such as tooth ...
Xu Younan +3 more
doaj
A high torque capacity eddy current damper used as a rate limiting device for a large solar array deployment mechanism is discussed. The eddy current damper eliminates the problems associated with the outgassing or leaking of damping fluids.
Ellis, R. C., Fink, R. A., Rich, R. W.
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Geophysical Research Letters, Volume 53, Issue 7, 16 April 2026.Abstract Ecosystem resilience, the ability to recover from disturbances, is crucial for sustaining ecosystem health and functionality. Traditional greenness‐based resilience measures often overlook early physiological stress. Here, we use solar‐induced chlorophyll fluorescence (SIF), an indicator for photosynthesis, to assess global vegetation ...
Subhrasita Behera +4 more
wiley +1 more source
The Unseen Crisis of Sharks and Rays in Senegal
Ecology and Evolution, Volume 16, Issue 4, April 2026.This study presents a conservative quantitative assessment of shark and ray landings and trade in Senegal, revealing extensive exploitation of threatened species. Surveys at two major artisanal processing sites in the Casamance region recorded over 170,000 individuals, mostly rays, with nearly all biomass comprising species at risk of extinction, and ...
Rima W. Jabado +3 more
wiley +1 more source
Jixie chuandong, 2012 Application of topological graphs to analyze and synthesize planetary gear trains is an effective approach in searching for innovative planetary gear trains.Topological graphs of basic structure and fundamental units of PGTs are discussed as the basis of
俞庆, 毛旭东
doaj
Learning Health Systems, Equity, and Bounded Justice: A Critical Scoping Review
Learning Health Systems, Volume 10, Issue 2, April 2026.ABSTRACT Introduction The science of learning health systems (LHSs) has expanded to include equity aims. However, efforts toward this end are nascent. The purpose of this study was to critically examine how equity has been discussed in LHS literature. Methods We conducted a critical scoping review informed by the bounded justice concept.
Vivetha Thambinathan +7 more
wiley +1 more source
An Approach to Multicriteria Optimization of the Three-Stage Planetary Gear Train
MachinesPlanetary gear trains offer numerous advantages over traditional gear systems, including high efficiency, the ability to handle large torque loads, and significant reductions in mass and size for the same torque capacity.
Jelena Stefanović-Marinović +4 more
doaj +1 more source
Gear tooth stress measurements on the UH-60A helicopter transmission [PDF]
The U.S. Army UH-60A (Black Hawk) 2200-kW (3000-hp) class twin-engine helicopter transmission was tested at the NASA Lewis Research Center. Results from these experimental (strain-gage) stress tests will enhance the data base for gear stress levels in ...
Oswald, Fred B.
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