Stratification effect on extreme-scale rolls in plane Couette flows

2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Sergio Gandía-Barberá ◽  
Francisco Alcántara-Ávila ◽  
Sergio Hoyas ◽  
Victor Avsarkisov
Keyword(s):  
Stratification Effect ◽  
Extreme Scale

Avalanche Stratification - Experimental Tests of the “Metastable Wedge” and “Continuous Flow” Models

2000 ◽  
Vol 627 ◽  
Author(s):  
M. E. Swanson ◽  
M. Landreman ◽  
J. Michel ◽  
J. Kakalios
Keyword(s):  
Continuous Flow ◽  
Granular Media ◽  
Experimental Tests ◽  
Coarse Sand ◽  
Angle Of Repose ◽  
Flow Models ◽  
Maximum Angle ◽  
Stratification Effect ◽  
Upward Moving ◽  
Moving Layer

ABSTRACTWhen an initially homogeneous binary mixture of granular media such as fine and coarse sand is poured near the closed edge of a “quasi-two-dimensional” Hele-Shaw cell consisting of two vertical transparent plates held a narrow distance apart, the mixture spontaneously forms alternating segregated layers. Experimental measurements of this stratification effect are reported in order to determine which model, one which suggests that segregation only occurs when the granular material contained within a metastable heap between the critical and maximum angle of repose avalanches down the free surface, or one for which the segregation results from smaller particles becoming trapped in the top surface and being removed from the moving layer during continuous flow. The result reported here indicate that the Metastable Wedge model provides a natural explanation for the initial mixed zone which precedes the formation of the layers, while the Continuous Flow model explains the observed upward moving kink of segregated material for higher granular flux rates, and that both mechansims are necessary in order to understand the observed pairing of segregated layersfor intermediate flow rates and cell separations.

Cardiovascular flow simulation at extreme scale

2009 ◽  
Vol 46 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Min Zhou ◽  
Onkar Sahni ◽  
H. Jin Kim ◽  
C. Alberto Figueroa ◽  
Charles A. Taylor ◽  
...  
Keyword(s):  
Flow Simulation ◽  
Cardiovascular Flow ◽  
Extreme Scale

Qualitative Discussion of Influences of some Factors on the Occurrence of Wind-Driven Coastal Upwelling Associated with “Aoshio” on the Northeast Shore of Tokyo Bay Using the Developed Analytical Model

2014 ◽  
Vol 641-642 ◽  
pp. 1040-1045
Author(s):  
Zhong Fan Zhu
Keyword(s):  
Analytical Model ◽  
Wind Shear ◽  
Coastal Upwelling ◽  
Tokyo Bay ◽  
Interfacial Friction ◽  
Observation Data ◽  
Shear Effect ◽  
Stratification Effect ◽  
Northeasterly Wind ◽  
Qualitative Discussion

An analytical model based on some solutions in the context of a two-layered fluid was developed to estimate the occurrence of northeasterly wind-driven coastal upwelling associated with “Aoshio” on the northeast shore of Tokyo Bay, and its validity was verified by comparing with observation data [1]. In this study, influences of all of the factors incorporated into this analytical model (including densities and thicknesses of the upper and lower layers, the parameter expressing the influences of interfacial friction and bottom friction) on the model are analyzed. The analytical model is found to express the competition between the wind-shear effect and the stratification effect: when the former dominates over the latter, Aoshio will occur on the northeast shore of the bay. The parameter that can be used to characterize the stratification effect can be simply expressed in terms of the product of density contrast and the square of thickness of the upper layer. Using different values of this parameter corresponding to different months in the model can simply estimate in which months it is easy for Aoshio phenomenon to happen on the northeast shore of the bay, and the result is roughly consistent with an observation phenomenon that Aoshio was frequently observed on the northeast shore of the bay in September and May and relatively less observed in June and July during 1978-2010.

scholarly journals PANDA: Extreme Scale Parallel K-Nearest Neighbor on Distributed Architectures

2016 ◽  
Author(s):  
Md. Mostofa Ali Patwary ◽  
Nadathur Rajagopalan Satish ◽  
Narayanan Sundaram ◽  
Jialin Liu ◽  
Peter Sadowski ◽  
...  
Keyword(s):  
Nearest Neighbor ◽  
K Nearest Neighbor ◽  
Distributed Architectures ◽  
Extreme Scale

NgCAM and VAMP2 Reveal that Direct Delivery and Dendritic Degradation Maintain Axonal Polarity

2021 ◽  
Author(s):  
Alec T. Nabb ◽  
Marvin Bentley
Keyword(s):  
Membrane Proteins ◽  
Molecular Mechanisms ◽  
Minor Role ◽  
Axonal Membrane ◽  
Quantitative Analyses ◽  
Direct Delivery ◽  
Novel Strategy ◽  
Extreme Scale ◽  
A Minor

Neurons are polarized cells of extreme scale and compartmentalization. To fulfill their role in electrochemical signaling, axons must maintain a specific complement of membrane proteins. Despite being subject of considerable attention, the trafficking pathway of axonal membrane proteins is not well understood. Two pathways, direct delivery and transcytosis, have been proposed. Previous studies reached contradictory conclusions about which of these mediates delivery of axonal membrane proteins to their destination, in part because they evaluated long-term distribution changes and not vesicle transport. We developed a novel strategy to selectively label vesicles in different trafficking pathways and determined the trafficking of two canonical axonal membrane proteins, NgCAM and VAMP2. Results from detailed quantitative analyses of transporting vesicles differed substantially from previous studies and found that axonal membrane proteins overwhelmingly undergo direct delivery. Transcytosis plays only a minor role in axonal delivery of these proteins. In addition, we identified a novel pathway by which wayward axonal proteins that reach the dendritic plasma membrane are targeted to lysosomes. These results redefine how axonal proteins achieve their polarized distribution, a crucial requirement for elucidating the underlying molecular mechanisms. [Media: see text] [Media: see text] [Media: see text] [Media: see text]

Design and analysis of a segmented blade for a 50 MW wind turbine rotor

2022 ◽  
pp. 0309524X2110693
Author(s):  
Alejandra S Escalera Mendoza ◽  
Shulong Yao ◽  
Mayank Chetan ◽  
Daniel Todd Griffith
Keyword(s):  
Wind Turbine ◽  
Large Mass ◽  
Turbine Rotor ◽  
Bolted Joints ◽  
Bonded Joints ◽  
Sheer Size ◽  
Extreme Scale ◽  
The Impact ◽  
Adhesive Materials ◽  
Wind Turbine Rotor

Extreme-size wind turbines face logistical challenges due to their sheer size. A solution, segmentation, is examined for an extreme-scale 50 MW wind turbine with 250 m blades using a systematic approach. Segmentation poses challenges regarding minimizing joint mass, transferring loads between segments and logistics. We investigate the feasibility of segmenting a 250 m blade by developing design methods and analyzing the impact of segmentation on the blade mass and blade frequencies. This investigation considers various variables such as joint types (bolted and bonded), adhesive materials, joint locations, number of joints and taper ratios (ply dropping). Segmentation increases blade mass by 4.1%–62% with bolted joints and by 0.4%–3.6% with bonded joints for taper ratios up to 1:10. Cases with large mass growth significantly reduce blade frequencies potentially challenging the control design. We show that segmentation of an extreme-scale blade is possible but mass reduction is necessary to improve its feasibility.

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