scholarly journals Flash Heating and Local Fluid Pressurization Lead to Rapid Weakening in Water‐Saturated Fault Gouges

2018 ◽  
Vol 123 (10) ◽  
pp. 9084-9100 ◽  
Author(s):  
Lu Yao ◽  
Shengli Ma ◽  
Jianye Chen ◽  
Toshihiko Shimamoto ◽  
Honglin He
Keyword(s):  
Fault Gouges ◽  
Fluid Pressurization ◽  
Water Saturated

An Environmental Wet Cell For High Voltage Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 18-19
Author(s):  
N.J. Tighe ◽  
H.M. Flower ◽  
P.R. Swann
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Image Quality ◽  
Inelastic Scattering ◽  
High Voltage ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Environmental Cell ◽  
Water Saturated ◽  
High Temperature Gas

A differentially pumped environmental cell has been developed for use in the AEI EM7 million volt microscope. In the initial version the column of gas traversed by the beam was 5.5mm. This permited inclusion of a tilting hot stage in the cell for investigating high temperature gas-specimen reactions. In order to examine specimens in the wet state it was found that a pressure of approximately 400 torr of water saturated helium was needed around the specimen to prevent dehydration. Inelastic scattering by the water resulted in a sharp loss of image quality. Therefore a modified cell with an ‘airgap’ of only 1.5mm has been constructed. The shorter electron path through the gas permits examination of specimens at the necessary pressure of moist helium; the specimen can still be tilted about the side entry rod axis by ±7°C to obtain stereopairs.

scholarly journals Experimental studies on the transformation from firn to ice in the wet-snow zone of temperate glaciers

1997 ◽  
Vol 24 ◽  
pp. 181-185 ◽  
Author(s):  
Katsuhisa Kawashima ◽  
Tomomi Yamada
Keyword(s):  
Experimental Studies ◽  
Ice Formation ◽  
Compression Tests ◽  
Densification Rate ◽  
Overburden Pressure ◽  
Proportionality Constant ◽  
Wet Snow ◽  
Water Saturated ◽  
The Relationship ◽  
Good Agreement

The densification of water-saturated firn, which had formed just above the firn-ice transition in the wet-snow zone of temperate glaciers, was investigated by compression tests under pressures ranging from 0.036 to 0.173 MPa, with special reference to the relationship between densification rate, time and pressure. At each test, the logarithm of the densification rate was proportional to the logarithm of the time, and its proportionality constant increased exponentially with increasing pressure. The time necessary for ice formation in the firn aquifer was calculated using the empirical formula obtained from the tests. Consequently, the necessary time decreased exponentially as the pressure increased, which shows that the transformation from firn in ice can be completed within the period when the firn aquifer exists, if the overburden pressure acting on the water-saturated firn is above 0.12–0.14 MPa. This critical value of pressure was in good agreement with the overburden pressure obtained from depth–density curves of temperate glaciers. It was concluded that the depth of firn–ice transition was self-balanced by the overburden pressure to result in the concentration between 20 and 30 m.

scholarly journals Where we Come from and where to Go: Six Decades of Botanical Studies in the Mediterranean Wetlands, with Sardinia (Italy) as a Case Study

Wetlands ◽  
2021 ◽  
Vol 41 (6) ◽  
Author(s):  
Alba Cuena-Lombraña ◽  
Mauro Fois ◽  
Annalena Cogoni ◽  
Gianluigi Bacchetta
Keyword(s):  
Vascular Plants ◽  
Vascular Plant ◽  
Regional Scale ◽  
Temporary Ponds ◽  
Evolutionary Strategies ◽  
Plant Groups ◽  
Research Themes ◽  
The Mediterranean ◽  
Taxonomic Groups ◽  
Water Saturated

AbstractPlants are key elements of wetlands due to their evolutionary strategies for coping with life in a water-saturated environment, providing the basis for supporting nearly all wetland biota and habitat structure for other taxonomic groups. Sardinia, the second largest island of the Mediterranean Basin, hosts a great variety of wetlands, of which 16 are included in eight Ramsar sites. The 119 hydro- and hygrophilous vascular plant taxa from Sardinia represent the 42.6% and 37.9% of the number estimated for Italy and Europe, respectively. Moreover, around 30% of Sardinia’s bryological flora, which is made up of 498 taxa, is present in temporary ponds. An overview at regional scale considering algae is not available, to our knowledge, even though several specific studies have contributed to their knowledge. In order to find the most investigated research themes and wetland types, identify knowledge gaps and suggest recommendations for further research, we present a first attempt to outline the work that has been hitherto done on plants in lentic habitats in Sardinia. Three plant groups (algae, bryophytes and vascular plants), and five research themes (conservation, ecology, inventory, palaeobotany and taxonomy) were considered. After a literature review, we retained 202 papers published from 1960 to 2019. We found that studies on vascular plants, as plant group, were disproportionately more numerous, and inventories and ecology were the most investigated research themes. Although efforts have recently been made to fill these long-lasting gaps, there is a need for updating the existing information through innovative methods and integrative approaches.

scholarly journals Compaction front and pore fluid pressurization in horizontally shaken drained granular layers

2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Shahar Ben-Zeev ◽  
Einat Aharonov ◽  
Renaud Toussaint ◽  
Stanislav Parez ◽  
Liran Goren
Keyword(s):  
Pore Fluid ◽  
Fluid Pressurization ◽  
Granular Layers
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