Tracing Fluid Flow in Flooded Chalk under Long Term Test Conditions

2013 ◽  
Author(s):  
R.I. Korsnes ◽  
U. Zimmermann ◽  
M.V. Madland ◽  
S.A.R. Bertolino ◽  
T. Hildebrand-Habel ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Test Conditions

Examination of some microbiological and biochemical parameters and tests of product quality used in a long-term fertilization trial

1998 ◽  
Vol 13 (3) ◽  
pp. 138-144 ◽  
Author(s):  
Joachim Raupp
Keyword(s):  
Food Storage ◽  
Optimal Conditions ◽  
Social Psychological ◽  
Optimal Test ◽  
Test Conditions ◽  
Environmental Criteria ◽  
Degradation Tests ◽  
Reliable Parameter ◽  
Chemical Contents

AbstractOn the basis of investigations with samples from a fertilization trial started in 1980, some parameters of food storage ability are evaluated. Microbial infestation of the product during incubation seems to be the most reliable parameter, but the circumstances of infestation and the optimal test conditions are unknown. There are no reliable correlations among the results of degradation tests, storage tests under optimal conditions, and chemical contents of the product. The concept of product vitality (a product-oriented quality referring to a product full of vigor) is based on results of degradation tests. Ultimately, however, food quality standards are based on human priorities (human-oriented). Therefore, not only product characteristics, but also social, psychological, and environmental criteria should be considered.

scholarly journals Evolution of Fracture Aperture in Quartz Sandstone under Hydrothermal Conditions: Mechanical and Chemical Effects

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 657
Author(s):  
Chaojie Cheng ◽  
Harald Milsch
Keyword(s):  
Fluid Flow ◽  
Hydraulic Fracture ◽  
Chemical Equilibrium ◽  
Pore Fluid ◽  
Pressure Solution ◽  
Fracture Aperture ◽  
Hydraulic Aperture ◽  
Mechanical Aperture ◽  
Stagnant Flow

Fractures efficiently affect fluid flow in geological formations, and thereby determine mass and energy transport in reservoirs, which are not least exploited for economic resources. In this context, their response to mechanical and thermal changes, as well as fluid–rock interactions, is of paramount importance. In this study, a two-stage flow-through experiment was conducted on a pure quartz sandstone core of low matrix permeability, containing one single macroscopic tensile fracture. In the first short-term stage, the effects of mechanical and hydraulic aperture on pressure and temperature cycles were investigated. The purpose of the subsequent intermittent-flow long-term (140 days) stage was to constrain the evolution of the geometrical and hydraulic fracture properties resulting from pressure solution. Deionized water was used as the pore fluid, and permeability, as well as the effluent Si concentrations, were systematically measured. Overall, hydraulic aperture was shown to be significantly less affected by pressure, temperature and time, in comparison to mechanical aperture. During the long-term part of the experiment at 140 °C, the effluent Si concentrations likely reached a chemical equilibrium state within less than 8 days of stagnant flow, and exceeded the corresponding hydrostatic quartz solubility at this temperature. This implies that the pressure solution was active at the contacting fracture asperities, both at 140 °C and after cooling to 33 °C. The higher temperature yielded a higher dissolution rate and, consequently, a faster attainment of chemical equilibrium within the contact fluid. X-ray µCT observations evidenced a noticeable increase in fracture contact area ratio, which, in combination with theoretical considerations, implies a significant decrease in mechanical aperture. In contrast, the sample permeability, and thus the hydraulic fracture aperture, virtually did not vary. In conclusion, pressure solution-induced fracture aperture changes are affected by the degree of time-dependent variations in pore fluid composition. In contrast to the present case of a quasi-closed system with mostly stagnant flow, in an open system with continuous once-through fluid flow, the activity of the pressure solution may be amplified due to the persistent fluid-chemical nonequilibrium state, thus possibly enhancing aperture and fracture permeability changes.

Sediment mobilization deposits from episodic subsurface fluid flow—A new tool to reveal long-term earthquake records?

Geology ◽  
2016 ◽  
Vol 44 (4) ◽  
pp. 243-246 ◽  
Author(s):  
A. Reusch ◽  
J. Moernaut ◽  
F.S. Anselmetti ◽  
M. Strasser
Keyword(s):  
Fluid Flow ◽  
Earthquake Records ◽  
Subsurface Fluid ◽  
Sediment Mobilization

Effect of plastic fragments on hydraulic characteristics of pretreated municipal solid waste

2006 ◽  
Vol 43 (12) ◽  
pp. 1333-1343 ◽  
Author(s):  
Mingliang Xie ◽  
Dirk Aldenkortt ◽  
Jean-Frank Wagner ◽  
Gerhard Rettenberger
Keyword(s):  
Fluid Flow ◽  
Hydraulic Conductivity ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Conceptual Model ◽  
Hydraulic Properties ◽  
Thin Sheet ◽  
Biological Pretreatment ◽  
Soil Material

A systematic study was undertaken of the granular composition and hydraulic properties of municipal solid waste (MSW) produced by mechanical–biological pretreatment (MBP–MSW) from three different treatment plants with the aim of evaluating the potential application of MBP–MSW as an alternative barrier material for landfill final cover systems. Despite its coarse granular composition, MBP–MSW has low hydraulic conductivity. Long-term permeability tests show that the hydraulic conductivity decreases with time. The most likely explanation for the long-term changes in permeability is the swelling of organic material contained within the compost. In the case of saturated flow, the virtually impermeable plastic fragments embedded in the material impede fluid flow. In the unsaturated case, such fragments slow down the drying process by disrupting fluid flow and allowing pooling of water above horizontally oriented fragments. The larger the number and size of the plastic fragments, the greater the influence on hydraulic conductivity and shrinkage. These processes can be better understood with the newly developed conceptual model, the thin-sheet model. Based on this conceptual model, laboratory tests were undertaken to compare natural soil material with mixtures of soil material and plastic fragments. Corresponding numerical simulations of some experiments verified the influence of plastic fragments on the hydraulic properties of MBP–MSW.Key words: mechanical–biological pretreatment, municipal solid waste (MSW), thin-sheet model, plastic fragment, hydraulic conductivity, drying test.

Polygonal fault systems on the mid-Norwegian margin: a long-term source for fluid flow

2003 ◽  
Vol 216 (1) ◽  
pp. 283-290 ◽  
Author(s):  
Christian Berndt ◽  
Stefan Bünz ◽  
Jürgen Mienert
Keyword(s):  
Fluid Flow ◽  
Fault Systems ◽  
Norwegian Margin ◽  
Polygonal Fault

Gate Oxide Long-Term Reliability of 4H-SiC MOS Devices

2010 ◽  
Vol 645-648 ◽  
pp. 805-808 ◽  
Author(s):  
Liang Chun Yu ◽  
Kin P. Cheung ◽  
Greg Dunne ◽  
Kevin Matocha ◽  
John S. Suehle ◽  
...  
Keyword(s):  
High Field ◽  
Field Data ◽  
Gate Oxide ◽  
Early Prediction ◽  
Accelerated Test ◽  
Mos Capacitors ◽  
Mos Devices ◽  
Test Conditions ◽  
Oxide Reliability

Reliability of the gate oxide on SiC is a pressing concern for deploying SiC MOS-based devices in real systems. While good projected oxide reliability was obtained recently under highly accelerated test conditions, indication that such projection may not be valid at lower operating fields was also reported. In this work, results from long-term TDDB stress (over 7 months) at 6 MV/cm and 300 °C on 4H-SiC MOS capacitors is reported. We confirm that lifetime projection from high-field data continues to be valid and no change in field acceleration factor is observed. The discrepancy between our results and the early prediction of poor reliability is examined.

Surface-Controlled Reactivity of Metal Carbonates

1996 ◽  
Vol 432 ◽  
Author(s):  
P. V. Brady
Keyword(s):  
Fluid Flow ◽  
Surface Chemistry ◽  
Crystal Nucleation ◽  
Metal Sorption ◽  
Common Component ◽  
Metal Carbonates ◽  
Metal Carbonate ◽  
Control Growth ◽  
Engineered Structures

AbstractMetal carbonate surfaces are a common component of soils, sediments, terrestrial organisms, and many engineered structures. The surface-controlled growth and dissolution of metal carbonate minerals (e.g. calcite) often affects fluid flow in pipes (through scaling) as well as the nanoscale assembly of complex biologic structures (similar reactions control Ca levels in the oceans, and ultimately, long-term CO2 levels). Engineering metal carbonate surface chemistry to enhance or inhibit growth, dissolution, or crystal nucleation is therefore an area with obvious economic impact. Metal carbonate superstructures are rapidly altered by dissolution/re-precipitation reactions, necessitating the measurement of surface chemistry near equilibrium. Measurements of metal sorption using limited residence time reactors point to the importance of adsorbed/exchanged metal ions in controlling surface charge and electrokinetic behavior. The same reactions appear to control growth and dissolution rates as well.

scholarly journals The Corinth Rift Laboratory or an in situ Investigation on Interactions between Fluids and Active Faults

2007 ◽  
Vol SpecialIssue ◽  
pp. 35-38 ◽  
Author(s):  
F. H. Cornet
Keyword(s):  
Fluid Flow ◽  
Deformation Process ◽  
Active Faults ◽  
Localization Of Deformation

Earthquakes result from the sudden acceleration of a preliminary long-term slow deformation process. The objective of the Corinth Rift Laboratory (CRL) is to investigate <i>in situ</i> this quasistatic deformation process and mechanisms leading to a sudden catastrophic acceleration. Of particular interest is the characterization of the structure of the deforming zones and of the progressive localization of deformation. Special attention is given to the role of fluids but also on the influence of faults on regional fluid flow <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.s01.20.2007" target="_blank">10.2204/iodp.sd.s01.20.2007</a>

scholarly journals Restoration of rostral cerebrospinal fluid flow to solve treatment failure caused by obstruction in long-term intrathecal baclofen administration

2019 ◽  
pp. 1-10
Author(s):  
Elmar M. Delhaas ◽  
Biswadjiet S. Harhangi ◽  
Pieter J. van Doormaal ◽  
Wouter Dinkelaar ◽  
Ad C.G.M. van Es ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Fluid Flow ◽  
Treatment Failure ◽  
Intrathecal Baclofen ◽  
Cerebrospinal Fluid Flow
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