scholarly journals Influence of water models on water movement through AQP1

2021 ◽  
Author(s):  
Miguel Angel Gonzalez ◽  
Alberto Zaragoza ◽  
Charlotte Lynch ◽  
Mark S.P. Sansom ◽  
Chantal Valeriani
Keyword(s):  
Water Movement ◽  
Influence Of Water ◽  
Water Models

Shallow sublittoral ecosystems in the Inner Hebrides

1983 ◽  
Vol 83 ◽  
pp. 161-183
Author(s):  
R. Mitchell ◽  
R. C. Earll ◽  
F. A. Dipper
Keyword(s):  
Water Movement ◽  
Scuba Diving ◽  
Light Penetration ◽  
Habitat Types ◽  
Nature Conservancy ◽  
Descriptive Account ◽  
Influence Of Water ◽  
Biogeographical Regions ◽  
Shallow Seas ◽  
Northern Species

SynopsisRapid advances in scientific SCUBA diving have provided a means of investigating the previously difficult ground of the shallow sublittoral. Dhing surveys of the Inner Hebridean islands have been promoted and coordinated by the Nature Conservancy Council (NCC) and the Underwater Conservation Society (UCS) to provide appropriate data for reviewing the marine nature conservation importance of the area. Although the surveys have been extensive rather than intensive, and many areas have yet to be investigated, a short preliminary descriptive account of the communities of the shallow seas of the Inner Hebrides is presented in this paper.The classification and description of sublittoral habitats is essentially related to the substratum type and the influence of water movement and light penetration. Although the diversity of habitat types is probably less for the Inner Hebrides than either the outer islands or the mainland, the larger islands show a range of exposure from the sheltered mud of sea lochs to wave- and tide-exposed bedrock. The juxtaposition of three marine biogeographical regions around the British Isles is reflected in the biota of the Inner Hebrides. In addition to the typical ‘Scottish’ sublittoral biota there is an associated assemblage of south-western species, and a number of northern species at their south-western limit. In many areas the diversity of the biota is reduced by the intense grazing of the sea urchin Echinus esculentus, a notably Scottish phenomenon.

The Behaviour of Barnacle Cyprids in Relation to Water Movement over a Surface

1955 ◽  
Vol 32 (3) ◽  
pp. 569-590 ◽  
Author(s):  
D. J. CRISP
Keyword(s):  
Water Flow ◽  
Velocity Gradient ◽  
Water Movement ◽  
Solid Particles ◽  
Water Current ◽  
Solid Boundary ◽  
Velocity Gradients ◽  
Solid Objects ◽  
Influence Of Water ◽  
Glass Tubes

1. The velocity gradient of the fluid close to the solid boundary is the most appropriate description of the conditions of water flow which affect the attachment of the larvae of sessile forms to solid objects. The nominal speed of the water movement past the object is of importance only in so far as it influences the velocity gradient in the boundary layer. 2. Experiments in glass tubes on cypris larvae of Elminius modestus and Balanus balanoides show that moderate velocity gradients exceeding 500 sec.-1 sweep the cyprids past the surface before they can attach. For large objects exposed to turbulent flow, the critical velocity gradient corresponds very approximately to a flow of 1-2 knots. 3. Attachment under conditions of water flow is accompanied by negative rheotaxy, and can occur equally in the light and in the dark. 4. Maximum attachment occurs at or below velocity gradients just great enough for the cyprid to be able to maintain position by swimming along the surface against the current. 5. Once the cyprid has attached it cannot be pulled off the surface even by gradients greatly in excess of those which prevent attachment. 6. Cyprids can migrate in all directions when exposed to moderate gradients, but they do so only with difficulty when the velocity gradient is high, particularly if the water is flowing in the same direction as that in which the cyprids are walking. The direction in which the cyprid migrates is altered only momentarily by changes in the direction of the current, the animal actively resisting the redistribution of forces acting on it. 7. No direct evidence is given in this paper on the influence of water currents on fixation, but a critical comparison with other published work suggests that fixation can occur in places where the velocity gradients are greater than those which limit attachment, provided the cypris is able to migrate there after attachment. 8. Moderate velocity gradients have little effect on the orientation at metamorphosis. Individuals tend to settle with the anterior end pointing downstream rather than in any other position. This orientation is the opposite from that which would be expected if the cyprid were passively orientated by the water current, but is likely to make subsequent feeding more efficient. 9. The ability to attach under conditions of water flow, and the tendency not to attach under stagnant conditions, may have an important influence on the animals' distribution and survival. 10. Solid particles in suspension may profoundly influence the behaviour, hence the results given in this paper may not be relevant to conditions where scouring takes place.

Towards more efficient soil-water modelling: moisture profiles with constant surface water content

1980 ◽  
Vol 95 (2) ◽  
pp. 417-422 ◽  
Author(s):  
G. D. Towner
Keyword(s):  
Surface Water ◽  
Finite Difference ◽  
Soil Water ◽  
Water Movement ◽  
Large Body ◽  
Close Relation ◽  
Water Models ◽  
Moisture Profiles ◽  
Soil Water Properties ◽  
Soil Water Movement

There exists a large body of soil-water theory for ‘modelling’ soil-water movement and distribution. Yet simpler and sometimes cruder methods are often preferred. In part this preference is due to the fact that theory is not yet able to solve completely the more complicated situations that occur naturally, such as the intermittent application or removal of water in the presence of very hysteric soil-water properties. But in many instances it is due to the apparent difficulty of the analysis for the non-mathematically minded. For example, descriptions have been given of soil-water models, based on direct physical arguments, that are in fact finite difference analyses of the governing partial differential equations, but which make no reference to such equations or their existence. Indeed, the impression is sometimes given that soil-water physicists produce unnecessary, irrelevant and complicated analyses for something that is really quite simple. Unfortunately, the simpler approaches bypass possible complications that are revealed by the mathematically based analyses. It is therefore the purpose of this paper to take advantage of the close relation between the two approaches, and to draw attention to the steps that may be taken to avoid or reduce possible difficulties when following the simpler methods. In particular, it is hoped that the paper will lead to a more efficient use of computing facilities.

Influence of Water Contamination on Performance of Nonequilibrium Disk MHD Generator

2001 ◽  
Vol 121 (8) ◽  
pp. 1005-1010
Author(s):  
Kumiko Ohgaki ◽  
Tetsuji Okamura ◽  
Yoshihiro Okuno ◽  
Tetsuya Suekane ◽  
Hiroyuki Yamasaki ◽  
...  
Keyword(s):  
Water Contamination ◽  
Mhd Generator ◽  
Influence Of Water
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