Viscous stability of parallel streams of superposed fluids

1974 ◽  
Vol 17 (5) ◽  
pp. 879 ◽  
Author(s):  
Norio Hayakawa
Keyword(s):  
Parallel Streams ◽  
Superposed Fluids

scholarly journals Promoting Generalized Learning in Balance Recovery Interventions

2021 ◽  
Vol 11 (3) ◽  
pp. 402
Author(s):  
Sara A. Harper ◽  
Anne Z. Beethe ◽  
Christopher J. Dakin ◽  
David A. E. Bolton
Keyword(s):  
Older Adults ◽  
Motor Learning ◽  
Daily Life ◽  
Balance Training ◽  
Community Dwelling ◽  
Specific Training ◽  
Balance Recovery ◽  
Parallel Streams ◽  
Postural Perturbations ◽  
Community Dwelling Older Adults

Recent studies have shown balance recovery can be enhanced via task-specific training, referred to as perturbation-based balance training (PBT). These interventions rely on principles of motor learning where repeated exposure to task-relevant postural perturbations results in more effective compensatory balance responses. Evidence indicates that compensatory responses trained using PBT can be retained for many months and can lead to a reduction in falls in community-dwelling older adults. A notable shortcoming with PBT is that it does not transfer well to similar but contextually different scenarios (e.g., falling sideways versus a forward trip). Given that it is not feasible to train all conditions in which someone could fall, this limited transfer presents a conundrum; namely, how do we best use PBT to appropriately equip people to deal with the enormous variety of fall-inducing scenarios encountered in daily life? In this perspective article, we draw from fields of research that explore how general learning can be promoted. From this, we propose a series of methods, gleaned from parallel streams of research, to inform and hopefully optimize this emerging field where people receive training to specifically improve their balance reactions.

scholarly journals Study of the geometry of open channels in a layer-bed-type microfluidic immobilized enzyme reactor

2021 ◽  
Author(s):  
Cynthia Nagy ◽  
Robert Huszank ◽  
Attila Gaspar
Keyword(s):  
Immobilized Enzyme ◽  
High Surface ◽  
Volume Ratio ◽  
Volumetric Flow Rate ◽  
Enzyme Reactor ◽  
Channel Pattern ◽  
Immobilized Enzyme Reactor ◽  
Split Flow ◽  
Parallel Streams ◽  
Enzymatic Microreactors

AbstractThis paper aims at studying open channel geometries in a layer-bed-type immobilized enzyme reactor with computer-aided simulations. The main properties of these reactors are their simple channel pattern, simple immobilization procedure, regenerability, and disposability; all these features make these devices one of the simplest yet efficient enzymatic microreactors. The high surface-to-volume ratio of the reactor was achieved using narrow (25–75 μm wide) channels. The simulation demonstrated that curves support the mixing of solutions in the channel even in strong laminar flow conditions; thus, it is worth including several curves in the channel system. In the three different designs of microreactor proposed, the lengths of the channels were identical, but in two reactors, the liquid flow was split to 8 or 32 parallel streams at the inlet of the reactor. Despite their overall higher volumetric flow rate, the split-flow structures are advantageous due to the increased contact time. Saliva samples were used to test the efficiencies of the digestions in the microreactors. Graphical abstract

VidCloud

2021 ◽  
Vol 5 (4) ◽  
pp. 1-32
Author(s):  
Abubakr O. Al-Abbasi ◽  
Vaneet Aggarwal
Keyword(s):  
Video Streaming ◽  
Distributed Storage ◽  
Convex Combination ◽  
Video Quality ◽  
Moment Generating Function ◽  
Content Delivery Network ◽  
Two Stage ◽  
Erasure Code ◽  
Probabilistic Scheduling ◽  
Parallel Streams

As video-streaming services have expanded and improved, cloud-based video has evolved into a necessary feature of any successful business for reaching internal and external audiences. In this article, video streaming over distributed storage is considered where the video segments are encoded using an erasure code for better reliability. We consider a representative system architecture for a realistic (typical) content delivery network (CDN). Given multiple parallel streams/link between each server and the edge router, we need to determine, for each client request, the subset of servers to stream the video, as well as one of the parallel streams from each chosen server. To have this scheduling, this article proposes a two-stage probabilistic scheduling. The selection of video quality is also chosen with a certain probability distribution that is optimized in our algorithm. With these parameters, the playback time of video segments is determined by characterizing the download time of each coded chunk for each video segment. Using the playback times, a bound on the moment generating function of the stall duration is used to bound the mean stall duration. Based on this, we formulate an optimization problem to jointly optimize the convex combination of mean stall duration and average video quality for all requests, where the two-stage probabilistic scheduling, video quality selection, bandwidth split among parallel streams, and auxiliary bound parameters can be chosen. This non-convex problem is solved using an efficient iterative algorithm. Based on the offline version of our proposed algorithm, an online policy is developed where servers selection, quality, bandwidth split, and parallel streams are selected in an online manner. Experimental results show significant improvement in QoE metrics for cloud-based video as compared to the considered baselines.

scholarly journals Shallow mixing layers between non-parallel streams in a flat-bed wide channel

2021 ◽  
Vol 916 ◽  
Author(s):  
Zhengyang Cheng ◽  
George Constantinescu
Keyword(s):  
Mixing Layers ◽  
Wide Channel ◽  
Parallel Streams

Abstract

scholarly journals Encoding of Stimulus Frequency and Sensor Motion in the Posterior Medial Thalamic Nucleus

2008 ◽  
Vol 100 (2) ◽  
pp. 681-689 ◽  
Author(s):  
Radi Masri ◽  
Tatiana Bezdudnaya ◽  
Jason C. Trageser ◽  
Asaf Keller
Keyword(s):  
Barrel Cortex ◽  
Stimulus Frequency ◽  
Response Duration ◽  
Stimulation Frequency ◽  
Response Latencies ◽  
Medial Nucleus ◽  
Anesthetized Rats ◽  
Reticular Activating System ◽  
Parallel Streams ◽  
Posterior Medial Nucleus

In all sensory systems, information is processed along several parallel streams. In the vibrissa-to-barrel cortex system, these include the lemniscal system and the lesser-known paralemniscal system. The posterior medial nucleus (POm) is the thalamic structure associated with the latter pathway. Previous studies suggested that POm response latencies are positively correlated with stimulation frequency and negatively correlated with response duration, providing a basis for a phase locked loop-temporal decoding of stimulus frequency. We tested this hypothesis by analyzing response latencies of POm neurons, in both awake and anesthetized rats, to vibrissae deflections at frequencies between 0.3 and 11 Hz. We found no significant, systematic correlation between stimulation frequency and the latency or duration of POm responses. We obtained similar findings from recording in awake rats, in rats under different anesthetics, and in anesthetized rats in which the reticular activating system was stimulated. These findings suggest that stimulus frequency is not reliably reflected in response latency of POm neurons. We also tested the hypothesis that POm neurons respond preferentially to sensor motion, that is, they respond to whisking in air, without contacts. We recorded from awake, head-restrained rats while monitoring vibrissae movements. All POm neurons responded to passive whisker deflections, but none responded to noncontact whisking. Thus like their counterparts in the trigeminal ganglion, POm neurons may not reliably encode whisking kinematics. These observations suggest that POm neurons might not faithfully encode vibrissae inputs to provide reliable information on vibrissae movements or contacts.

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