Vortex Persistence: A Recent Model for Stratified Entrainment and Its Application to Geophysical Flows

2000 ◽  
pp. 119-125
Author(s):  
A. J. Cotel ◽  
R. E. Breidenthal
Keyword(s):  
Recent Model ◽  
Geophysical Flows

Vortex Evolution in Realistic Geophysical Flows.

1996 ◽  
Author(s):  
Donald P. Delisi ◽  
Robert E. Robins
Keyword(s):  
Geophysical Flows

Sitting above the maze: recent model discoveries in molecular science

2014 ◽  
Vol 41 (1-3) ◽  
pp. 205-229 ◽  
Author(s):  
Feng Wang ◽  
Marawan Ahmed
Keyword(s):  
Recent Model ◽  
Molecular Science

scholarly journals First experimental evidence for the CO<sub>2</sub>-driven origin of Stromboli's major explosions

2011 ◽  
Vol 3 (1) ◽  
pp. 411-430 ◽  
Author(s):  
A. Aiuppa ◽  
M. Burton ◽  
P. Allard ◽  
T. Caltabiano ◽  
G. Giudice ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Co2 Emission ◽  
Weight Ratio ◽  
Co2 Flux ◽  
Recent Model ◽  
Stromboli Volcano ◽  
Plumbing System ◽  
Gas Leakage ◽  
Basaltic Volcanoes ◽  
Monitoring Strategies

Abstract. We report on the first detection of CO2 flux precursors of the till now unforecastable larger than normal ("major") explosions that intermittently occur at Stromboli volcano (Italy). Automated survey of the crater plume emissions in the period 2006–2010, during which 12 such explosions happened, demonstrate that these events are systematically preceded by a brief phase of increasing CO2/SO2 weight ratio (up to >40) and CO2 flux (>1300 t/d) with respect to the time-averaged values of 3.7 and ~500 t/d typical for standard Stromboli's activity. These signals are best explained by the accumulation of CO2-rich gas at a discontinuity of the plumbing system (decreasing CO2 emission at the surface), followed by increasing gas leakage prior to the explosion. Our observations thus support the recent model of Allard (2010) for a CO2-rich gas trigger of recurrent major explosions at Stromboli, and demonstrate the possibility to forecast these events in advance from geochemical precursors. These observations and conclusions have clear implications for monitoring strategies at other open-vent basaltic volcanoes worldwide.

Driving Force Behind the O-Rh(001) Clock Reconstruction

1998 ◽  
Vol 12 (20) ◽  
pp. 849-857 ◽  
Author(s):  
Chang Q. Sun
Keyword(s):  
Driving Force ◽  
Electrostatic Force ◽  
Bond Formation ◽  
Lone Pair ◽  
Atomic Ratio ◽  
Recent Model ◽  
Dual Roles ◽  
Low Energy Electron Diffraction ◽  
Dipole Interactions ◽  
Low Energy Electron

A novel rhombi-chain network is derived from low energy electron diffraction experimental observations and the recent model theory, revealing that the O-Rh(100) clock-rotation is driven by an electrostatic force arisen from bond formation. Thus the O-Rh bond suffers from tension other than compression, or strain relief. As O -1 evolves into the hybridized- O -2,a Rh 5 O cluster in the c(2 × 2) phase develops into a Rh 4 O tetrahedron and yields the overall (2 × 2)p4g reconstruction. In the (2 × 2)p4g phase, the hollow-sited O -2 defines one Rh + ion and two lone-pair-induced Rh dipoles of its four surface neighbors. The surface atomic ratio (O : Rh = 1 : 2) allocates, therefore, half of the surface Rh atoms to be the Rh dipoles and another half to play dual roles of Rh + ion and Rh dipole. Interactions along the "dipole–dipole – Rh +/dipole – Rh +/dipole" strings create the rhombi-chain at the <11> directions, and a responding bond tension confines the (2 × 2)p4g clock rotation.

Comment on a recent model of the iron complex in spinach ferredoxin

1966 ◽  
Vol 24 (6) ◽  
pp. 877-879 ◽  
Author(s):  
J.H.M. Thornley ◽  
J.F. Gibson ◽  
F.R. Whatley ◽  
D.O. Hall
Keyword(s):  
Iron Complex ◽  
Recent Model

Simulating zonation in geophysical flows by laboratory experiments

2013 ◽  
Vol 25 (8) ◽  
pp. 086602 ◽  
Author(s):  
G. Di Nitto ◽  
S. Espa ◽  
A. Cenedese
Keyword(s):  
Laboratory Experiments ◽  
Geophysical Flows

scholarly journals VIV Excitation Competition Between Bare and Buoyant Segments of Flexible Cylinders

2013 ◽  
Author(s):  
Zhibiao Rao ◽  
J. Kim Vandiver ◽  
Vikas Jhingran
Keyword(s):  
Model Test ◽  
Practical Problem ◽  
Excitation Frequency ◽  
Ocean Basin ◽  
Recent Model ◽  
Total Amplitude ◽  
Vortex Induced Vibration ◽  
Pipe Model ◽  
Exploration And Production ◽  
Different Diameters

This paper addresses a practical problem: “Under which coverage of buoyancy modules, would the Vortex Induced Vibration (VIV) excitation on buoyant segments dominate the response?” This paper explores the excitation competition between bare and buoyant segments of a 38 meter long model riser. The source of data is a recent model test, conducted by SHELL Exploration and Production at the MARINTEK Ocean Basin in Trondheim Norway. A pipe model with five buoyancy configurations was tested. The results of these tests show that (1) the excitation on the bare and buoyant regions could be identified by frequency, because the bare and buoyant regions are associated with two different frequencies due to the different diameters; (2) a new phenomenon was observed; A third frequency in the spectrum is found not to be a multiple of the frequency associated with either bare or buoyancy regions, but the sum of the frequency associated with bare region and twice of the frequency associated with buoyancy region; (3) the contribution of the response at this third frequency to the total amplitude is small; (4) the power dissipated by damping at each excitation frequency is the metric used to determine the winner of excitation competition. For most buoyancy configurations, the excitation on buoyancy regions dominates the VIV response; (5) a formula is proposed to predict the winner of the excitation competition between bare and buoyant segments for a given buoyancy coverage.

scholarly journals Internal vs Forced Variability Metrics for Geophysical Flows Using Information Theory

2021 ◽  
Author(s):  
Aakash Sane ◽  
Baylor Fox-Kemper ◽  
David Ullman
Keyword(s):  
Information Theory ◽  
Geophysical Flows
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