Looking for an optimal flow shape for culture growth in vortex bioreactors, an intriguing and impressive structure has been observed that mimics the strong swirling flows in the atmosphere (tornado) and ocean (waterspout). To better understand the flow nature and topology, this experimental study explores the development of vortex breakdown (VB) in a lab-scale swirling flow of two immiscible fluids filling a vertical cylindrical container. The rotating bottom disk drives the circulation of both fluids while the sidewall is stationary. The container can be either sealed with the still top disk (SC) or open (OC). As the rotation strength (Re) increases, a new circulation cell occurs in each fluid-the dual VB. In case SC, VB first emerges in the lower fluid at Re = 475 and then in the upper fluid at Re = 746. In case OC, VB first emerges in the upper fluid at Re = 524 and then in the lower fluid at Re = 538. The flow remains steady and axisymmetric with the interface and the free surface being just slightly deformed in the studied range of Re. Such two-VB swirling flows can provide efficient mixing in aerial or two-fluid bioreactors.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9022139 | PMC |
http://dx.doi.org/10.1038/s41598-021-02514-6 | DOI Listing |
ACS Nano
January 2025
Functional Materials Research Laboratory, School of Materials Science and Engineering, Tongji University, Shanghai 201804, P. R. China.
Polar vortices are predominantly observed within the confined ferroelectric films and the ferroelectric/paraelectric superlattices. This raises the intriguing question of whether polar vortices can form within relaxor ferroelectric ceramics and subsequently contribute to their energy storage performances. Here, we incorporate 10 mol % CaSnO into the 0.
View Article and Find Full Text PDFNeurosci Biobehav Rev
December 2024
Centre for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford, UK; Department of Psychiatry, University of Oxford, Oxford, UK; Center for Music in the Brain, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark. Electronic address:
Turbulence is a universal principle for fast energy and information transfer. Moving beyond the turbulence of fluid dynamics, turbulence has recently been demonstrated in brain dynamics. Importantly, turbulence can be expressed as the rich variability across spacetime of the local levels of synchronisation of coupled brain signals.
View Article and Find Full Text PDFFish Physiol Biochem
February 2025
Centre for the Research and Technology of Agro-Environment and Biological Sciences (CITAB), University of Trás-Os-Montes and Alto Douro (UTAD), Vila Real, Portugal.
Animal welfare is a growing concern in aquaculture practices. Stress induced by handling or transportation can lead to negative impacts on the sector. Zebrafish has raised as an important aquaculture model, but still with few focus on its stress response in early life stages.
View Article and Find Full Text PDFSci Adv
November 2024
Department of Dermatology, Xiangya Hospital, Central South University, Changsha 410008, China.
Nan Fang Yi Ke Da Xue Xue Bao
October 2024
Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing 100091, China.
Objective: To culture and expand primary rat aortic vascular stem cells in vitro and evaluate their characteristics as mesenchymal stem cells.
Methods: The thoracic and abdominal aortas isolated from 2- to 3-week-old Sprague-Dawley rats were cut into vascular segments 2.0 mm in length and cultured in culture flasks till adhesion and solidification of the outer membranes.
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