scholarly journals REGIONAL FLOW‐ECOLOGY RELATIONSHIPS IN SMALL, TEMPERATE RIVERS

2021 ◽  
Author(s):  
Ian Hough ◽  
Helen Moggridge ◽  
Philip Warren ◽  
James Shucksmith
Keyword(s):  
Regional Flow

scholarly journals Myocardial extraction and retention of 2-iododesmethylimipramine: a novel flow marker

1986 ◽  
Vol 250 (6) ◽  
pp. H1060-H1070 ◽  
Author(s):  
S. E. Little ◽  
J. M. Link ◽  
K. A. Krohn ◽  
J. B. Bassingthwaighte
Keyword(s):  
Escape Rate ◽  
Flow Imaging ◽  
Rapid Loss ◽  
Ideal Flow ◽  
Regional Flow ◽  
Myocardial Flow

An ideal deposition marker for measuring regional flow is completely extracted during transcapillary passage and permanently retained. beta-Labeled desmethylimipramine ([3H]DMI) is a nearly ideal flow marker. To obtain gamma- and positron-emitting markers, DMI was iodinated to form 2-iododesmethylimipramine (IDMI). IDMI was more lipophilic than DMI. In isolated saline-perfused rabbit hearts its transorgan extraction was greater than 99%; and retention was greater than 98% at 5 min at mean flows of up to 3.5 ml X g-1 X min-1. During washout, the fractional escape rate was less than 0.1% X min-1 and was independent of flow. In isolated blood-perfused rabbit hearts, extraction was still 98%, but retention was as low as 86% after 5 min at a flow of 1.6 ml X g-1 X min-1. The fractional escape rate was up to 2% X min-1 but independent of flow. Despite this relatively rapid loss, regional IDMI deposition remains proportional to regional flow for many minutes. Therefore IDMI is useful as an externally detectable "molecular microsphere" for myocardial flow imaging in vivo.

Revisiting simplified model of a single-well push-pull test for estimating regional flow velocity

2021 ◽  
pp. 126711
Author(s):  
Quanrong Wang ◽  
Aohan Jin ◽  
Hongbin Zhan ◽  
Yu Chen ◽  
Wenguang Shi ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Simplified Model ◽  
Pull Test ◽  
Regional Flow ◽  
Single Well

Hydrogeochemical indications of regional flow in the Lower Greensand aquifer of the London Basin

2021 ◽  
pp. qjegh2021-028
Author(s):  
W. George Darling ◽  
Melinda A. Lewis
Keyword(s):  
Environmental Isotopes ◽  
Published Data ◽  
Confined Aquifer ◽  
The West ◽  
Content Type ◽  
Regional Flow ◽  
Fresh Perspective ◽  
Southern Side ◽  
Chalk Aquifer ◽  
The City

The Lower Greensand (LGS) forms the second most important aquifer in the London Basin but, being largely absent beneath the city itself, has received much less attention than the ubiquitous overlying Chalk aquifer. While the general directions of groundwater flow in the Chalk are well established, there has been much less certainty about flow in the LGS owing to regionally sparse borehole information. This study focuses on two hitherto uncertain aspects of the confined aquifer: the sources of recharge to the west-central London Basin around Slough, and the fate of LGS water where the aquifer thins out on the flank of the London Platform in the Gravesend–Medway–Sheppey area on the southern side of the basin. The application of hydrogeochemical techniques including environmental isotopes indicates that recharge to the Slough area is derived from the northern LGS outcrop, probably supplemented by downward leakage from the Chalk, while upward leakage from the LGS in North Kent is mixing with Chalk water to the extent that some Chalk boreholes on the Isle of Sheppey are abstracting high proportions of water with an LGS fingerprint. In doing so, this study demonstrates the value of re-examining previously published data from a fresh perspective.Thematic collection: This article is part of the Hydrogeology of Sandstone collection available at: https://www.lyellcollection.org/cc/hydrogeology-of-sandstone

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