Multiple cool flames in static, unstirred reactors under reduced-gravity and terrestrial conditions

2007 ◽  
Vol 148 (4) ◽  
pp. 280-284 ◽  
Author(s):  
H PEARLMAN
Keyword(s):  
Reduced Gravity ◽  
Cool Flames

Validation Test Report for OCEANS 1.0: The 1/40 Global, Reduced Gravity NRL Layered Ocean Model

1998 ◽  
Author(s):  
E. J. Metzger ◽  
Robert C. Rhodes ◽  
Dong S. Ko ◽  
Harley E. Hurlburt
Keyword(s):  
Ocean Model ◽  
Reduced Gravity ◽  
Test Report ◽  
Validation Test

scholarly journals Modulation of spatial and temporal modules in lower limb muscle activations during walking with simulated reduced gravity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shota Hagio ◽  
Makoto Nakazato ◽  
Motoki Kouzaki
Keyword(s):  
Matrix Factorization ◽  
Lower Limb ◽  
Nonnegative Matrix Factorization ◽  
Walking Speed ◽  
Nonnegative Matrix ◽  
Tensor Decomposition ◽  
Reduced Gravity ◽  
Dependent Variables ◽  
Specific Speed ◽  
Muscle Activations

AbstractGravity plays a crucial role in shaping patterned locomotor output to maintain dynamic stability during locomotion. The present study aimed to clarify the gravity-dependent regulation of modules that organize multiple muscle activities during walking in humans. Participants walked on a treadmill at seven speeds (1–6 km h−1 and a subject- and gravity-specific speed determined by the Froude number (Fr) corresponding to 0.25) while their body weight was partially supported by a lift to simulate walking with five levels of gravity conditions from 0.07 to 1 g. Modules, i.e., muscle-weighting vectors (spatial modules) and phase-dependent activation coefficients (temporal modules), were extracted from 12 lower-limb electromyographic (EMG) activities in each gravity (Fr ~ 0.25) using nonnegative matrix factorization. Additionally, a tensor decomposition model was fit to the EMG data to quantify variables depending on the gravity conditions and walking speed with prescribed spatial and temporal modules. The results demonstrated that muscle activity could be explained by four modules from 1 to 0.16 g and three modules at 0.07 g, and the modules were shared for both spatial and temporal components among the gravity conditions. The task-dependent variables of the modules acting on the supporting phase linearly decreased with decreasing gravity, whereas that of the module contributing to activation prior to foot contact showed nonlinear U-shaped modulation. Moreover, the profiles of the gravity-dependent modulation changed as a function of walking speed. In conclusion, reduced gravity walking was achieved by regulating the contribution of prescribed spatial and temporal coordination in muscle activities.

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