scholarly journals Decoherence induced by a dynamic spin environment: The universal regime

2008 ◽  
Vol 77 (2) ◽  
Author(s):  
Cecilia Cormick ◽  
Juan Pablo Paz
2020 ◽  
Vol 117 (23) ◽  
pp. 239901
Author(s):  
Qian Chen ◽  
Xuezhong Ruan ◽  
Honglei Yuan ◽  
Xiaochao Zhou ◽  
Zhaoxia Kou ◽  
...  
Keyword(s):  

2010 ◽  
Vol 82 (3) ◽  
Author(s):  
Pui-Wai Ma ◽  
S. L. Dudarev ◽  
A. A. Semenov ◽  
C. H. Woo
Keyword(s):  

1984 ◽  
Vol 17 (27) ◽  
pp. 4819-4835 ◽  
Author(s):  
S E Nagler ◽  
W J L Buyers ◽  
R L Armstrong ◽  
R A Ritchie

2021 ◽  
Author(s):  
Daniel Richards ◽  
Sam Pegler ◽  
Sandra Piazolo ◽  
Oliver Harlen

<div>Antarctic ice flow shows deviation from the deformation regimes of pure and simple shear. By analysing the vorticity number from surface velocity data it is found that approximately 80% of the flow is outside these regimes. These deformations are both between pure and simple shear, as well as highly rotational, highlighting the need for fabric predictions away from the commonly studied regimes of pure and simple shear. </div><div>We use the numerical scheme SpecCAF, which has been shown to accurately reproduce experimentally observed fabrics with no free parameters, to study ice fabrics in such general deformations. By exploring the parameter space of temperature and vorticity number, we present a definitive classification of fabrics patterns which arise, and construct a universal regime diagram for ice fabrics under general two-dimensional deformation. We find that intermediate deformations see a smooth transition between a cone-shape fabric and a secondary cluster. We present the first investigation of the fabrics produced in highly rotational deformations, which produce a weak girdle fabric with the axis aligned to the vorticity axis. We also show that across deformation and temperature space fabrics only reach a true steady-state above strains of 200%, and there is significant variation in this across the parameter space.  </div>


Author(s):  
Andrew J. Provenza ◽  
Carlos R. Morrison

A novel wireless device which transfers supply power through induction to rotating operational amplifiers and transmits low voltage AC signals to and from a rotating body by way of radio telemetry has been successfully demonstrated in the NASA Glenn Research Center (GRC) Dynamic Spin Test Facility. In the demonstration described herein, a rotating operational amplifier provides controllable AC power to a piezoelectric patch epoxied to the surface of a rotating Ti plate. The amplitude and phase of the sinusoidal voltage command signal, transmitted wirelessly to the amplifier, was tuned to completely suppress the 3rd bending resonant vibration of the plate. The plate’s 3rd bending resonance was excited using rotating magnetic bearing excitation while it spun at slow speed in a vacuum chamber. A second patch on the opposite side of the plate was used as a sensor. This paper discusses the characteristics of this novel device, the details of a spin test, results from a preliminary demonstration, and future plans.


2015 ◽  
Vol 1 (1) ◽  
pp. 98 ◽  
Author(s):  
Telma Elizabete de Moraes ◽  
Silvio César Moral Marques
Keyword(s):  

Norberto Bobbio vê no estado democrático o único meio capaz de colocar as pessoas em igualdade de condições e de garantir a existência e continuidade das liberdades fundamentais, refletindo sobre o contraste que existe entre os ideais democráticos e a “democracia real”. Daí a necessidade de concentrar a discussão entre o que foi prometido e o efetivamente praticado, ou seja, tentar um prognóstico sobre as “promessas” não cumpridas. Para o autor, o termo democracia apresentar-se-ia sob dois aspectos: primeiro como “um conjunto de instituições ou técnicas de governo”, sendo essas o “sufrágio universal, regime parlamentar, reconhecimento dos direitos civis, princípios da maioria”; em segundo lugar, como “um certo ideal a ser perseguido”. Assim, a democracia define-se como técnica de governo e meio empregado para organizar a sociedade e, como ideal, propõe a busca por um fim desejado, i.e., a igualdade entre os homens, somente alcançada pela educação.


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