Water content in natural eclogite and implication for water transport into the deep upper mantle

Lithos ◽  
2006 ◽  
Vol 86 (3-4) ◽  
pp. 245-259 ◽  
Author(s):  
I KATAYAMA ◽  
S NAKASHIMA ◽  
H YURIMOTO
Keyword(s):  
Water Content ◽  
Water Transport ◽  
Upper Mantle

Transient Water Transport in Nafion Membranes Under Activity Gradients

2010 ◽  
Author(s):  
T. Romero ◽  
W. Me´rida
Keyword(s):  
Water Content ◽  
Water Transport ◽  
Water Activity ◽  
Thickness Variation ◽  
Membrane Thickness ◽  
Membrane Interface ◽  
Rational Representation ◽  
Transport Measurements ◽  
Nafion Membranes ◽  
The Time Domain

Transient water transport experiments on Nafion of different thicknesses were carried out in the temperature range of 30 to 70 °C. These experiments report on water transport measurements under activity gradients in the time domain for liquid and vapour equilibrated Nafion membranes. Using a permeability test rig with a gated valve, the water crossover was measured as a function of time. The typical response is shown as a time dependent flux, and it shows the dynamic transport from an initially dry condition up to the final steady state. Contrarily to previous reports from dynamic water transport measurements, where the activity gradient across the membrane is absent; in this work, the membrane was subjected to an activity gradient acting as the driving force to transport water from an environment with higher water activity to an environment with lower water activity through the membrane’s structure. Measurements explored temperature and membrane thickness variation effect on the transient response. Results showed dependency on temperature and a slower water transport rate across the vapour-membrane interface than for the liquid-membrane interface. These measurements showed the transport dependency on water content at the beginning of the experiment when the membrane was in a close-to-dry condition suggesting a transport phenomenon transition due to a reached critical water content value. The new protocol for transient measurements proposed here will allow the characterization of water transport dependency on membrane water content with a more rational representation of the membrane-environment interface.

Pyroxenes can be used to estimate upper mantle water content

Eos ◽  
2014 ◽  
Vol 95 (36) ◽  
pp. 332-332
Author(s):  
JoAnna Wendel
Keyword(s):  
Water Content ◽  
Upper Mantle

Effect of saline drinking water on the size and water content of the gut and other organs of male and female mallards

2002 ◽  
Vol 80 (1) ◽  
pp. 70-76 ◽  
Author(s):  
M R Hughes ◽  
D C Bennett ◽  
T M Sullivan
Keyword(s):  
Drinking Water ◽  
Water Content ◽  
Water Transport ◽  
Anas Platyrhynchos ◽  
Salt Glands ◽  
Male And Female ◽  
Organ Mass ◽  
Hind Gut

Ducks absorb imbibed Na+ and water in the anterior gut and reabsorb Na+ and water from urine refluxed into the hind gut. In Mallards (Anas platyrhynchos) this process is sexually disparate: males reflux and reabsorb more water, mainly in the ceca. We examined the effect of saline acclimation on the size of Mallard organs, especially the gut and other osmoregulatory organs (kidneys, salt glands) in both sexes. We tested and accept two hypotheses: (1) saline increases the mass of the Mallard hind gut and other osmoregulatory organs and (2) saline has a greater effect on the organs of males. Drinking saline did not affect the mass of body, kidney, heart, or liver, but increased the mass of the salt glands, ileum, and ceca. Increases in organ mass were greater in males than in females. Saline acclimation increased the length of the jejunum only in males and decreased the length of the esophagus and the length and mass of the proventriculus only in females. Our data suggest that the upper and lower gut segments may play somewhat different roles in ion and water transport in the two sexes.

Effects of Drugs on Mucus Glycoproteins and Water in Bronchial Secretion

1979 ◽  
Vol 7 (5) ◽  
pp. 434-442 ◽  
Author(s):  
T C Medici ◽  
P Radielovic
Keyword(s):  
Water Content ◽  
Water Transport ◽  
Animal Experiments ◽  
Osmotic Gradient ◽  
Bronchial Mucosa ◽  
Bronchial Secretion ◽  
Epithelial Surface ◽  
Bronchial Mucus ◽  
Mucus Glycoproteins

The result of chemical analysis of the bronchial secretion is simple; up to 95% of the secretion is made up of water, and up to 5% is composed of ash, protein, carbohydrate, lipid, nitrogen and desoxyribonucleic acid. More complicated is the question of how bronchial secretion is formed and of which active biological components it is composed. Bronchial secretion is the result of the different processes, secretion, transudation, exudation and exfoliation from a highly differentiated bronchial mucosa. To those substances secreted belong, amongst others, constituents important for the flow properties and the transportability of the secretion: the bronchial mucus glycoproteins and water. The bronchial glycoproteins are the most important group, constituting 50–80% of the macromolecules. They are formed and secreted by the bronchial mucosa. The synthesis and secretion of bronchial glycoproteins are influenced by drugs in different ways. Beta-adrenergic stimulants do not alter these processes in in vitro studies on human glands, although an increase in mucus of glycoprotein production has been demonstrated in animal experiments and indirectly in man. Cyclic adenosine monophosphate and the methylxanthines stimulate mucus glycoprotein production, anticholinergic agents reduce but do not completely supress this process. Anti-allergic agents do not alter the production of bronchial glycoproteins with the exception of the corticosteroids which partially inhibit the synthesis and secretion. Neither expectorants nor mucolytic agents influence the production of mucus glycoproteins in human bronchial glands as opposed to animal experiments, in which these compounds produce an increase in the output of the bronchial fluid. Water constitutes 95% of the bronchial secretion and the water content considerably influences mucociliary function. An osmotic gradient, the result of active sodium and chloride ion transport across the bronchial epithelium, ensures on the one hand that water diffuses through epithelium on to the epithelial surface where it forms the serous sol layer in which the cilia beat. On the other hand water is probably transported in the same way across the mucosal glands where it mixes with the extremely hydrophilic mucus glycoproteins. The ion and water transport is influenced by drugs. Acetylcholine, histamine and terbutaline stimulate the ion and thereby water transport. Atropine, diphenylhydramine, an H1-antagonist, propranolol, a beta-blocker andfurosemide inhibit these transport mechanisms. Whether ketotifen, a new antihistaminic drug used in the treatment of bronchial asthma, will affect these processes, decreasing the water content of bronchial mucus, remains to be seen.

On the fate of water in the formation of rocky planets

2021 ◽  
Author(s):  
Lindy Elkins-Tanton ◽  
Jenny Suckale ◽  
Sonia Tikoo
Keyword(s):  
Water Content ◽  
Upper Mantle ◽  
Lower Mantle ◽  
Plate Tectonics ◽  
Solidus Temperature ◽  
Magma Ocean ◽  
Excess Water ◽  
Low Degree ◽  
Giant Impacts ◽  
Rocky Planets

<p>Rocky planets go through at least one and likely multiple magma ocean stages, produced by the giant impacts of accretion. Planetary data and models show that giant impacts do not dehydrate either the mantle or the atmosphere of their target planets. The magma ocean liquid consists of melted target material and melted impactor, and so will be dominated by silicate melt, and also contain dissolved volatiles including water, carbon, and sulfur compounds.</p><p>As the magma ocean cools and solidifies, water and other volatiles will be incorporated into the nominally anhydrous mantle phases up to their saturation limits, and will otherwise be enriched in the remaining, evolving magma ocean liquids. The water content of the resulting cumulate mantle is therefore the sum of the traces in the mineral grains, and any water in trapped interstitial liquids. That trapped liquid fraction may in fact be by far the largest contributor to the cumulate water budget.</p><p>The water and other dissolved volatiles in the evolving liquids may quickly reach the saturation limit of magmas near the surface, where pressure is low, but degassing the magma ocean is likely more difficult than has been assumed in some of our models. To degas into the atmosphere, the gases must exsolve from the liquid and form bubbles, and those bubbles must be able to rise quickly enough to avoid being dragged down by convection and re-dissolved at higher pressures. If bubbles are buoyant enough (that is, large enough) to decouple from flow and rise, then they are also dynamically unstable and liable to be torn into smaller bubbles and re-entrained. This conundrum led to the hypothesis that volatiles do not significantly degas until a high level of supersaturation is reached, and the bubbles form a buoyant layer and rise in diapirs in a continuum dynamics sense. This late degassing would have the twin effects of increasing the water content of the cumulates, and of speeding up cooling and solidification of the planet.</p><p>Once the mantle is solidified, the timeclock until the start of plate tectonics begins. Modern plate tectonics is thought to rely on water to lower the viscosity of the asthenosphere, but plate tectonics is also thought to be the process by which water is brought into the mantle. Magma ocean solidification, however, offers two relevant processes. First, following solidification the cumulate mantle is gravitationally unstable and overturns to stability, carrying water-bearing minerals from the upper mantle through the transition zone and into the lower mantle. Upon converting to lower-mantle phases, these minerals will release their excess water, since lower mantle phases have lower saturation limits, thus fluxing the upper mantle with water. Second, the mantle will be near its solidus temperature still, and thus its viscosity will be naturally low. When fluxed with excess water, the upper mantle would be expected to form a low degree melt, which if voluminous enough with rise to help form the earliest crust, and if of very low degree, will further reduce the viscosity of the asthenosphere.</p>

The electrical conductivity of upper-mantle rocks: water content in the upper mantle

2007 ◽  
Vol 35 (3) ◽  
pp. 157-162 ◽  
Author(s):  
Duojun Wang ◽  
Heping Li ◽  
Li Yi ◽  
Baoping Shi
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Upper Mantle

Correlation of Structural Changes at Different Levels of the Jejunal Villus with Positive and Negative Net Water Transport in Vivo and in Vitro

1975 ◽  
Vol 53 (3) ◽  
pp. 439-450 ◽  
Author(s):  
T. F. McElligott ◽  
I. T. Beck ◽  
P. K. Dinda ◽  
S. Thompson
Keyword(s):  
Epithelial Cells ◽  
Water Content ◽  
Water Transport ◽  
Structural Changes ◽  
Morphological Changes ◽  
Sugar Transport ◽  
Apical Part ◽  
Different Levels

Experiments were done for identification and localization of certain structural changes at different levels of jejunal villus of the hamster during positive and negative water transport across the intestine in vivo and in vitro. Positive transport occurred when the mucosal surface of the intestine was bathed (in vitro experiments) or perfused (in vivo experiments) with isotonic Krebs–Ringer bicarbonate solution containing 10 mM glucose, and negative water transport was achieved by rendering this solution hypertonic with 150 mM mannitol. Results indicate that during positive net water transport, the intestine in vivo transported more fluid and exhibited a more conspicuous dilatation of the lateral intercellular spaces (L.I.S.) than did the in vitro preparation. Dilatation of the L.I.S. in both preparations was present only in the apical part of the villus, suggesting that this is the principal site of water absorption. When the mucosal solution was made hypertonic with mannitol, the L.I.S. in the in vivo intestine totally collapsed, whereas in the in vitro intestine these spaces remained open very slightly. These morphological changes correspond well with our finding that in the presence of the hypertonic mucosal solution there was a greater net negative water transport in vivo than in vitro. Incubation of the intestine in the isotonic mucosal solution produced subnuclear swelling of the mid-villus epithelial cells, and this morphological change was associated with an increase in the water content of the tissue. Perfusion of the in vivo intestine with the isotonic solution produced neither the swellings nor the increase in water content of the tissue. In the presence of hypertonic mucosal solution there was a water loss from the tissue both in vivo and in vitro, and these swellings were not observed. These results are discussed in relation to intestinal sugar transport and to the maturity of the epithelial cells, and it is concluded that transport studies on in vitro preparations may provide valid information on a qualitative basis, if not on a strictly quantitative basis.

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