Subsurface flow measurements using passive flux meters in variably‐saturated cold‐regions landscapes

2020 ◽  
Vol 34 (23) ◽  
pp. 4541-4546
Author(s):  
Élise G. Devoie ◽  
Ryan F. Connon ◽  
James R. Craig ◽  
William L. Quinton
Keyword(s):  
Subsurface Flow ◽  
Flow Measurements ◽  
Cold Regions

scholarly journals Invited Perspective: What Lies Beneath a Changing Arctic?

2020 ◽  
Author(s):  
Jeffrey M. McKenzie ◽  
Barret L. Kurylyk ◽  
Michelle A. Walvoord ◽  
Victor F. Bense ◽  
Daniel Fortier ◽  
...  
Keyword(s):  
Water Resources ◽  
Contaminant Transport ◽  
Subsurface Flow ◽  
The Arctic ◽  
Aquatic Environments ◽  
Societal Change ◽  
Surface Phenomena ◽  
Flow Paths ◽  
Cold Regions ◽  
Research Initiatives

Abstract. As permafrost thaws in the Arctic, new subsurface pathways open for the movement of groundwater, energy, and solutes. We identify different ways that these subsurface changes are driving observed surface phenomena, including the potential for increased contaminant transport, modification to water resources, and enhanced rates of infrastructure (e.g. buildings and roads) damage. Further, as permafrost thaws it allows groundwater to transport carbon, nutrients, and other dissolved constituents from terrestrial to aquatic environments via progressively deeper subsurface flow paths. Cryohydrogeology, the study of groundwater in cold regions, must be included in Northern research initiatives to account for this hidden catalyst of environmental and societal change.

scholarly journals Invited perspective: What lies beneath a changing Arctic?

2021 ◽  
Vol 15 (1) ◽  
pp. 479-484
Author(s):  
Jeffrey M. McKenzie ◽  
Barret L. Kurylyk ◽  
Michelle A. Walvoord ◽  
Victor F. Bense ◽  
Daniel Fortier ◽  
...  
Keyword(s):  
Water Resources ◽  
Contaminant Transport ◽  
Subsurface Flow ◽  
The Arctic ◽  
Aquatic Environments ◽  
Societal Change ◽  
Flow Paths ◽  
Cold Regions ◽  
Research Initiatives

Abstract. As permafrost thaws in the Arctic, new subsurface pathways open for the transport of groundwater, energy, and solutes. We identify different ways that these subsurface changes are driving observed surface consequences, including the potential for increased contaminant transport, modification to water resources, and enhanced rates of infrastructure (e.g. buildings and roads) damage. Further, as permafrost thaws it allows groundwater to transport carbon, nutrients, and other dissolved constituents from terrestrial to aquatic environments via progressively deeper subsurface flow paths. Cryohydrogeology, the study of groundwater in cold regions, should be included in northern research initiatives to account for this hidden catalyst of environmental and societal change.

Clinical and Experimental Analysis of 201Thallium Uptake of the Heart

1978 ◽  
Vol 17 (04) ◽  
pp. 142-148
Author(s):  
U. Büll ◽  
S. Bürger ◽  
B. E. Strauer
Keyword(s):  
Oxygen Consumption ◽  
Left Ventricle ◽  
Muscle Mass ◽  
Myocardial Oxygen Consumption ◽  
Animal Experiments ◽  
Left Ventricular ◽  
Left Ventricular Wall ◽  
Ventricular Wall ◽  
Flow Measurements ◽  
Myocardial Flow

Studies were carried out in order to determine the factors influencing myocardial 201T1 uptake. A total of 158 patients was examined with regard to both 201T1 uptake and the assessment of left ventricular and coronary function (e. g. quantitative ventriculography, coronary arteriography, coronary blood flow measurements). Moreover, 42 animal experiments (closed chest cat) were performed. The results demonstrate that:1) 201T1 uptake in the normal and hypertrophied human heart is linearly correlated with the muscle mass of the left ventricle (LVMM);2) 201T1 uptake is enhanced in the inner (subendocardial) layer and is decreased in the outer (subepicardial) layer of the left ventricular wall. The 201T1 uptake of the right ventricle is 40% lower in comparison to the left ventricle;3) the basic correlation between 201T1 uptake and LVMM is influenced by alterations of both myocardial flow and myocardial oxygen consumption; and4) inotropic interventions (isoproterenol, calcium, norepinephrine) as well as coronary dilatation (dipyridamole) may considerably augment 201T1 uptake in accordance with changes in myocardial oxygen consumption and/or myocardial flow.It is concluded that myocardial 201T1 uptake is determined by multiple factors. The major determinants have been shown to include (i) muscle mass, (ii) myocardial flow and (iii) myocardial oxygen consumption. The clinical data obtained from patient groups with normal ventricular function, with coronary artery disease, with left ventricular wall motion abnormalities and with different degree of left ventricular hypertrophy are correlated with quantitated myocardial 201T1 uptake.

Partition Coefficient of 133Xe between Blood and Eye Tissues

1975 ◽  
Vol 14 (04) ◽  
pp. 301-309
Author(s):  
A. Marczak ◽  
A. Moszczyńska-Kowalska ◽  
H. Kowalski
Keyword(s):  
Partition Coefficient ◽  
Aqueous Humour ◽  
Vitreous Body ◽  
Flow Measurements ◽  
Solubility Coefficient ◽  
Eye Muscles ◽  
Eye Tissues ◽  
Relative Solubility ◽  
Blood Flow Measurements

SummaryThe relative solubility coefficient of 133Xe and the tissue-blood partition coefficient for the aqueous humour vitreous body, conjunctiva and external eye muscles of the rabbit were determined in vitro at 37° C and at various haematocrit values. The partition coefficient for haematocrit 40 was: for the aqueous humour 0,49 ml/ml, for the vitreous body 0,50 ml/ml, for the conjunctiva 0,81 ml/g and for the external eye muscles 0,77 ml/g. It was found that the solubility of 133Xe in rabbit erythrocytes is about 50 per cent higher than that in human red cells. The consequences of this fact for the precision of blood flow measurements by the method of tissue clearance are discussed.

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