Changes over time in near‐saturated hydraulic conductivity of peat soil following reclamation for agriculture

2019 ◽  
Vol 34 (2) ◽  
pp. 237-243
Author(s):  
Jari Hyväluoma ◽  
Mari Räty ◽  
Janne Kaseva ◽  
Riikka Keskinen
Keyword(s):  
Hydraulic Conductivity ◽  
Peat Soil ◽  
Saturated Hydraulic Conductivity ◽  
Changes Over Time ◽  
Over Time

An evaluation of air permeability measurements to characterize the saturated hydraulic conductivity of soil reclamation covers

2015 ◽  
Vol 95 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Mingbin Huang ◽  
Heather Rodger ◽  
S. Lee Barbour
Keyword(s):  
Hydraulic Conductivity ◽  
Oil Sands ◽  
Land Reclamation ◽  
Air Permeability ◽  
Saturated Hydraulic Conductivity ◽  
Soil Reclamation ◽  
Air Entrapment ◽  
Soil Covers ◽  
Weathering Processes ◽  
Over Time

Huang, M., Rodger, H. and Barbour, S. L. 2015. An evaluation of air permeability measurements to characterize the saturated hydraulic conductivity of soil reclamation covers. Can. J. Soil Sci. 95: 15–26. The saturated hydraulic conductivity (Ks) of soil covers used in land reclamation is known to change over time as the result of weathering processes. Guelph permeameter (GP) measurements have been used to track the evolution of Ks for soil covers at an oil sands mine near Ft. McMurray, Alberta. Although successful, the method was time consuming and consequently a rapid method of estimating Ks based on in situ air permeability measurements was developed. The objectives of this study were: (1) to use air permeability measurements to characterize the spatial variations of Ks for typical reclamation soils and (2) to compare air permeability measurements to direct measurements obtained through laboratory and GP measurements. The results highlight that the values of Ks estimated from measured air permeability values were higher than the values of Ks measured directly using the GP. This is likely due to swelling of clay soils or air-entrapment during GP measurements. Although the magnitude was over-estimated, the variability of Ks was captured by the air permeability measurements. Consequently, a limited program of comparative GP and air permeameter measurements could be used to more rapidly characterize the Ks of reclamation covers over time.

scholarly journals Estimation of saturated hydraulic conductivity from ring infiltrometer test taking into account the surface moisture stain extension

2017 ◽  
Vol 65 (3) ◽  
pp. 321-324 ◽  
Author(s):  
Aurore Réfloch ◽  
Jean-Paul Gaudet ◽  
Laurent Oxarango ◽  
Yvan Rossier
Keyword(s):  
Hydraulic Conductivity ◽  
Saturated Hydraulic Conductivity ◽  
Alluvial Deposits ◽  
Test Taking ◽  
Surface Moisture ◽  
Infiltration Basin ◽  
Well Field ◽  
Single Ring ◽  
Over Time ◽  
Good Agreement

AbstractA large single-ring infiltrometer test was performed in order to characterize the saturated hydraulic conductivity below an infiltration basin in the well field of Lyon (France). Two kinds of data are recorded during the experiment: the volume of water infiltrated over time and the extension of the moisture stain around the ring. Then numerical analysis was performed to determine the saturated hydraulic conductivity of the soil by calibration.Considering an isotropic hydraulic conductivity, the saturated hydraulic conductivity of the alluvial deposits is estimated at 3.8 10−6m s−1. However, with this assumption, we are not able to represent accurately the extension of the moisture stain around the ring. When anisotropy of hydraulic conductivity is introduced, experimental data and simulation results are in good agreement, both for the volume of water infiltrated over time and the extension of the moisture stain. The vertical saturated hydraulic conductivity in the anisotropic configuration is 4.75 times smaller than in the isotropic configuration (8.0 10−7m s−1), and the horizontal saturated hydraulic conductivity is 125 times higher than the vertical saturated hydraulic conductivity (1.0 10−4m s−1).

Comparison of two devices for measuring exercise transcutaneous oxygen pressures in patients with claudication

VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 355-362 ◽  
Author(s):  
Marie Urban ◽  
Alban Fouasson-Chailloux ◽  
Isabelle Signolet ◽  
Christophe Colas Ribas ◽  
Mathieu Feuilloy ◽  
...  
Keyword(s):  
Oxygen Pressure ◽  
Optical Sensors ◽  
Chemical Sensors ◽  
Transcutaneous Oxygen ◽  
Starting Values ◽  
Two Systems ◽  
Transcutaneous Oxygen Pressure ◽  
New Sensors ◽  
Changes Over Time ◽  
Over Time

Abstract. Summary: Background: We aimed at estimating the agreement between the Medicap® (photo-optical) and Radiometer® (electro-chemical) sensors during exercise transcutaneous oxygen pressure (tcpO2) tests. Our hypothesis was that although absolute starting values (tcpO2rest: mean over 2 minutes) might be different, tcpO2-changes over time and the minimal value of the decrease from rest of oxygen pressure (DROPmin) results at exercise shall be concordant between the two systems. Patients and methods: Forty seven patients with arterial claudication (65 + / - 7 years) performed a treadmill test with 5 probes each of the electro-chemical and photo-optical devices simultaneously, one of each system on the chest, on each buttock and on each calf. Results: Seventeen Medicap® probes disconnected during the tests. tcpO2rest and DROPmin values were higher with Medicap® than with Radiometer®, by 13.7 + / - 17.1 mm Hg and 3.4 + / - 11.7 mm Hg, respectively. Despite the differences in absolute starting values, changes over time were similar between the two systems. The concordance between the two systems was approximately 70 % for classification of test results from DROPmin. Conclusions: Photo-optical sensors are promising alternatives to electro-chemical sensors for exercise oximetry, provided that miniaturisation and weight reduction of the new sensors are possible.

Neuropsychological Symptoms in Posttraumatic Stress Disorder and Changes Over Time

2007 ◽  
Author(s):  
Miranda Olff ◽  
Mirjam Nijdam ◽  
Kristin Samuelson ◽  
Julia Golier ◽  
Mariel Meewisse ◽  
...  
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Posttraumatic Stress ◽  
Stress Disorder ◽  
Neuropsychological Symptoms ◽  
Changes Over Time ◽  
Over Time

Changes Over Time in Adaptive Behavior Functioning of Twice-Exceptional Children

2010 ◽  
Author(s):  
Rebecca D. Stinson ◽  
Zachary Sussman ◽  
Megan Foley Nicpon ◽  
Allison L. Allmon ◽  
Courtney Cornick ◽  
...  
Keyword(s):  
Adaptive Behavior ◽  
Exceptional Children ◽  
Twice Exceptional ◽  
Changes Over Time ◽  
Over Time

Kategorisierung der Schädelform des Cavalier King Charles Spaniels

2019 ◽  
Vol 47 (02) ◽  
pp. 133-133
Keyword(s):  
Pilot Study ◽  
Cavalier King Charles Spaniel ◽  
Conformation Changes ◽  
Veterinary Record ◽  
Changes Over Time ◽  
Over Time

Knowler SP, Gillstedt L, Mitchell TJ et al. Pilot study of head conformation changes over time in the Cavalier King Charles spaniel breed. Veterinary Record 2019. doi:10.1136/vr.105135.

Uneven Decoupling

2019 ◽  
Vol 5 (4) ◽  
pp. 410-427 ◽  
Author(s):  
Ryan P. Thombs ◽  
Xiaorui Huang
Keyword(s):  
Economic Growth ◽  
Co2 Emissions ◽  
Ecological Modernization ◽  
Climate Mitigation ◽  
Data Limitations ◽  
Treadmill Of Production ◽  
Global North ◽  
Organization Of Production ◽  
Changes Over Time ◽  
Over Time

The macro-comparative decoupling literature has often sought to test the arguments made by the treadmill of production (TP) and ecological modernization (EM) theories. However, due to data limitations, these studies have been limited to analyzing the years after 1960. Given that both theories discuss historical processes operating before 1960, analyzing pre-1960 data is warranted to more comprehensively test the propositions made by both theories. We assess the long-term relationship between economic growth and CO2 emissions from 1870 to 2014 using a sample of global North nations. We use Prais-Winsten regression models with time interactions to assess whether, when, and how much CO2 emissions have decoupled from economic growth over time. We find that significant relative decoupling has occurred twice since 1870: during the last 30 years of the nineteenth century, the timing of which is contrary to what both the EM and TP theories might expect, and after 1970. We also observe that the relationship remained relatively stable from the turn of the twentieth century to approximately 1970, which aligns with the arguments made by the classical TP work. We conclude that shifts in the global organization of production have shaped the magnitude of the economic growth–CO2 emissions relationship and its changes over time, which has implications for climate mitigation policy.

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