Influence of pycnocline on settling behaviour of non-spherical particle and wake evolution.

Sci Rep

Institute of Geophysics, Polish Academy of Sciences, Ks. Janusza 64, 01-452, Warsaw, Poland.

Published: November 2020

Settling of non-spherical particles in a stratified fluid exhibits complex dynamics in a low-to-moderate inertia regime. Although this process is involved in a wide variety of phenomena in natural fluid systems, its fundamental mechanisms are still unexplored. Understanding of particle settling in microscale is particularly important to explain challenging problems associated with ecological and biogeochemical processes in the ocean due to the delayed settling of particulate matter at pycnoclines. Here, I explore interactions between disk-shaped particles and a stratified fluid with a density transition. By laboratory experiments, I demonstrate that the settling dynamics of the disk crossing a density transition are tightly coupled with the wake structure evolution, and I observe for the first time in a two-layer ambient configuration a bell-shaped structure that forms on a jet after the wake has detached from the particle. Furthermore, I identify hydrodynamic conditions for the variations of settling velocity and particle orientation instabilities. These findings shed light on particle settling mechanisms necessary to explain dynamics of marine particles such as plankton, faecal pellets, and microplastics and may improve the estimation methods of sedimentation processes in various areas of earth sciences and engineering.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7692520PMC
http://dx.doi.org/10.1038/s41598-020-77682-yDOI Listing

Publication Analysis

Top Keywords

particles stratified
8
stratified fluid
8
particle settling
8
density transition
8
settling
7
particle
5
influence pycnocline
4
pycnocline settling
4
settling behaviour
4
behaviour non-spherical
4

Similar Publications

The ternary complex effectively prevents droplet aggregation, Ostwald ripening, and phase separation through its gel network, thereby demonstrating its capability in bioactive compound delivery. In this work, the influence of varying chickpea protein isolate (CPI) levels on the microstructure, gel characteristics, stability and functional properties of grape seed proanthocyanidin (GSP) and konjac gum (KGM) stabilized ternary complexes was investigated. Visual appearance indicated the formation of a non-stratified ternary complex as the CPI enhanced to 3-4 %.

View Article and Find Full Text PDF

The rising production and improper disposal of titanium dioxide nanoparticles (TiO NPs) into aquatic systems present considerable environmental challenges, especially when these particles interact with other contaminants such as cadmium (Cd). Thus, the current study aimed to evaluate the potential toxic effects on the gills, chondrocranium, body growth, and mortality of Aquarana catesbeiana tadpoles. The tadpoles were exposed to environmentally relevant concentrations of TiO NPs (10 µg L), and CdCl (10 µg L), both individually and in combination, for 30 days (chronic exposure), along with a control group.

View Article and Find Full Text PDF

Microbial coalescence plays a crucial role in shaping aquatic ecosystems by facilitating the merging of neighboring microbial communities, thereby influencing ecosystem structure. Although this phenomenon is commonly observed in natural environments, comprehensive quantitative comparative studies on different lifestyle bacteria involved in this process are still lacking. The study focuses on 16S rRNA Amplicon Sequence Variants (ASVs) at the Jinsha River hydropower stations (Wudongde [WDD], Baihetan [BHT], Xiluodu [XLD], Xiangjiaba [XJB]), specifically examining free-living (FL) and particle-attached (PA) bacteria.

View Article and Find Full Text PDF

Microscale Electrical Resistivity Measurements to Investigate Particle Distribution.

Langmuir

January 2025

Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States.

The functional performance of a particulate thin film depends greatly on the particle distribution that forms during drying. In situ methods for monitoring the impact of different processing parameters on the distribution of particles currently require expensive and specialized equipment. This work addresses this gap by miniaturizing a geophysical prospecting method to thin-film applications.

View Article and Find Full Text PDF

Unveiling the role of stratified extracellular polymeric substances in membrane-based microalgae harvesting: Thermodynamic and computational insights.

Water Res

December 2024

State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai, 200092, PR China.

Membrane separation technology has emerged as a highly energy-efficient method for microalgae enrichment and harvesting in wastewater treatment. However, membrane fouling caused by algal cells and stratified extracellular polymeric substances (EPS) remains a critical barrier to its industrial-scale application. This study meticulously investigates the micro process of algae-derived pollutants stacking to the membrane surface affected by stratified EPS.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!