scholarly journals Meridional Heat and Salt Transport Across the Subantarctic Front by Cold‐Core Eddies

2019 ◽  
Vol 124 (2) ◽  
pp. 981-1004 ◽  
Author(s):  
Ramkrushnbhai S. Patel ◽  
Helen E. Phillips ◽  
Peter G. Strutton ◽  
Andrew Lenton ◽  
Joan Llort
Keyword(s):  
Salt Transport ◽  
Cold Core ◽  
Subantarctic Front

Cold-core anomalies at the subantarctic front, south of Tasmania

2004 ◽  
Vol 51 (11) ◽  
pp. 1417-1440 ◽  
Author(s):  
Rosemary Morrow ◽  
Jean-Rene Donguy ◽  
Alexis Chaigneau ◽  
Stephen R. Rintoul
Keyword(s):  
Cold Core ◽  
Subantarctic Front

Microstructure determines water and salt permeation in commercial ion exchange membranes

2018 ◽  
Author(s):  
Ryan Kingsbury ◽  
Shan Zhu ◽  
Sophie Flotron ◽  
Orlando Coronell
Keyword(s):  
Energy Efficiency ◽  
Ion Exchange ◽  
Electrolyte Solutions ◽  
Polymer Chains ◽  
Salt Transport ◽  
Mixing Energy ◽  
Electrochemical Processes ◽  
Highly Correlated ◽  
Salt Diffusion ◽  
Exchange Membrane

Ion exchange membrane (IEM) performance in electrochemical processes such as fuel cells, redox flow batteries, or reverse electrodialysis (RED) is typically quantified through membrane selectivity and conductivity, which together determine the energy efficiency. However, water and co-ion transport (i.e., osmosis and salt diffusion / fuel crossover) also impact energy efficiency by allowing uncontrolled mixing of the electrolyte solutions to occur. For example, in RED with hypersaline water sources, uncontrolled mixing consumes 20-50% of the available mixing energy. Thus, in addition to high selectivity and high conductivity, it is desirable for IEMs to have low permeability to water and salt in order to minimize energy losses. Unfortunately, there is very little quantitative water and salt permeability information available for commercial IEMs, making it difficult to select the best membrane for a particular application. Accordingly, we measured the water and salt transport properties of 20 commercial IEMs and analyzed the relationships between permeability, diffusion and partitioning according to the solution-diffusion model. We found that water and salt permeance vary over several orders of magnitude among commercial IEMs, making some membranes better-suited than others to electrochemical processes that involve high salt concentrations and/or concentration gradients. Water and salt diffusion coefficients were found to be the principal factors contributing to the differences in permeance among commercial IEMs. We also observed that water and salt permeability were highly correlated to one another for all IEMs studied, regardless of polymer type or reinforcement. This finding suggests that transport of mobile salt in IEMs is governed by the microstructure of the membrane, and provides clear evidence that mobile salt does not interact strongly with polymer chains in highly-swollen IEMs. <br>

scholarly journals Air-Sea Interactions over Eddies in the Brazil-Malvinas Confluence

2021 ◽  
Vol 13 (7) ◽  
pp. 1335
Author(s):  
Ronald Souza ◽  
Luciano Pezzi ◽  
Sebastiaan Swart ◽  
Fabrício Oliveira ◽  
Marcelo Santini
Keyword(s):  
Latent Heat ◽  
Large Scale ◽  
Surface Wind ◽  
Heat Fluxes ◽  
Lower Atmosphere ◽  
Meteorological Variables ◽  
Global Ocean ◽  
Study Region ◽  
Cold Core

The Brazil–Malvinas Confluence (BMC) is one of the most dynamical regions of the global ocean. Its variability is dominated by the mesoscale, mainly expressed by the presence of meanders and eddies, which are understood to be local regulators of air-sea interaction processes. The objective of this work is to study the local modulation of air-sea interaction variables by the presence of either a warm (ED1) and a cold core (ED2) eddy, present in the BMC, during September to November 2013. The translation and lifespans of both eddies were determined using satellite-derived sea level anomaly (SLA) data. Time series of satellite-derived surface wind data, as well as these and other meteorological variables, retrieved from ERA5 reanalysis at the eddies’ successive positions in time, allowed us to investigate the temporal modulation of the lower atmosphere by the eddies’ presence along their translation and lifespan. The reanalysis data indicate a mean increase of 78% in sensible and 55% in latent heat fluxes along the warm eddy trajectory in comparison to the surrounding ocean of the study region. Over the cold core eddy, on the other hand, we noticed a mean reduction of 49% and 25% in sensible and latent heat fluxes, respectively, compared to the adjacent ocean. Additionally, a field campaign observed both eddies and the lower atmosphere from ship-borne observations before, during and after crossing both eddies in the study region during October 2013. The presence of the eddies was imprinted on several surface meteorological variables depending on the sea surface temperature (SST) in the eddy cores. In situ oceanographic and meteorological data, together with high frequency micrometeorological data, were also used here to demonstrate that the local, rather than the large scale forcing of the eddies on the atmosphere above, is, as expected, the principal driver of air-sea interaction when transient atmospheric systems are stable (not actively varying) in the study region. We also make use of the in situ data to show the differences (biases) between bulk heat flux estimates (used on atmospheric reanalysis products) and eddy covariance measurements (taken as “sea truth”) of both sensible and latent heat fluxes. The findings demonstrate the importance of short-term changes (minutes to hours) in both the atmosphere and the ocean in contributing to these biases. We conclude by emphasizing the importance of the mesoscale oceanographic structures in the BMC on impacting local air-sea heat fluxes and the marine atmospheric boundary layer stability, especially under large scale, high-pressure atmospheric conditions.

Bile salt transport in intestinal lymph of the rat

1982 ◽  
Vol 12 (1) ◽  
pp. 23-27 ◽  
Author(s):  
GEOFFREY J. BECKETT ◽  
IAIN W. PERCY-ROBB
Keyword(s):  
Bile Salt ◽  
Salt Transport ◽  
Intestinal Lymph ◽  
Bile Salt Transport

scholarly journals Imaging Salt Uptake Dynamics in Plants Using PET

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Gerard Ariño-Estrada ◽  
Gregory S. Mitchell ◽  
Prasenjit Saha ◽  
Ahmad Arzani ◽  
Simon R. Cherry ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Sodium Transport ◽  
Crop Production ◽  
Small Animal ◽  
Region Of Interest ◽  
Salt Transport ◽  
Small Animal Pet ◽  
Transport Dynamics ◽  
Positron Emission ◽  
Over Time

AbstractSoil salinity is a global environmental challenge for crop production. Understanding the uptake and transport properties of salt in plants is crucial to evaluate their potential for growth in high salinity soils and as a basis for engineering varieties with increased salt tolerance. Positron emission tomography (PET), traditionally used in medical and animal imaging applications for assessing and quantifying the dynamic bio-distribution of molecular species, has the potential to provide useful measurements of salt transport dynamics in an intact plant. Here we report on the feasibility of studying the dynamic transport of 22Na in millet using PET. Twenty-four green foxtail (Setaria viridis L. Beauv.) plants, 12 of each of two different accessions, were incubated in a growth solution containing 22Na+ ions and imaged at 5 time points over a 2-week period using a high-resolution small animal PET scanner. The reconstructed PET images showed clear evidence of sodium transport throughout the whole plant over time. Quantitative region-of-interest analysis of the PET data confirmed a strong correlation between total 22Na activity in the plants and time. Our results showed consistent salt transport dynamics within plants of the same variety and important differences between the accessions. These differences were corroborated by independent measurement of Na+ content and expression of the NHX transcript, a gene implicated in sodium transport. Our results demonstrate that PET can be used to quantitatively evaluate the transport of sodium in plants over time and, potentially, to discern differing salt-tolerance properties between plant varieties. In this paper, we also address the practical radiation safety aspects of working with 22Na in the context of plant imaging and describe a robust pipeline for handling and incubating plants. We conclude that PET is a promising and practical candidate technology to complement more traditional salt analysis methods and provide insights into systems-level salt transport mechanisms in intact plants.

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