Water retention of arctic zone soils (Spitsbergen)

2013 ◽  
Vol 27 (4) ◽  
pp. 439-444 ◽  
Author(s):  
J. Melke ◽  
B. Witkowska-Walczak ◽  
P. Bartmiński
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Bulk Density ◽  
Size Distribution ◽  
Water Retention ◽  
Total Porosity ◽  
The Arctic ◽  
Arctic Zone ◽  
Retention Characteristics

Abstract The water retention characteristics of the arctic zone soils ((TurbicCryosol (Skeletic), TurbicCryosols (Siltic, Skeletic) and BrunicTurbicCryosol (Arenic)) derived in different micro-relief forms were determined. Water retention curves were similar in their course for the mud boils, cell forms, and sorted circles ie for TurbicCryosols. For these forms, the mud boils showed the highest water retention ability, whereas the sorted circles - the lowest one. Water retention curves for the tundra polygons (Brunic TurbicCryosol, Arenic) were substantially different from these mentioned above. The tundra polygons were characterized by the lowest bulk density of 1.26 g cm-3, whereas the sorted circles (TurbicCryosol, Skeletic) - the highest: 1.88 g cm-3. Total porosity was the highest for the tundra polygons (52.4 and 55.5%) and the lowest - for the sorted circles (28.8 and 26.2%). Pore size distribution of the investigated soils showed that independently of depths, the highest content of large and medium pores was noticed for the tundra polygons ie 21.2-24.2 and 19.9-18.7%, respectively. The lowest content of large pores was observed for the cell forms (6.4-5.9%) whereas the mud boils exhibited the lowest amount of medium sized pores (12.2-10.4%) (both TurbicCryosols Siltic, Skeletic). The highest content of small pores was detected in the mud boils - 20.4 and 19.0%.

scholarly journals Accounting for evolving pore size distribution in water retention models for compacted clays

2014 ◽  
Vol 39 (7) ◽  
pp. 702-723 ◽  
Author(s):  
Gabriele Della Vecchia ◽  
Anne-Catherine Dieudonné ◽  
Cristina Jommi ◽  
Robert Charlier
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Water Retention ◽  
Retention Models ◽  
Compacted Clays

scholarly journals Prediction of soil water retention properties using pore-size distribution and porosity

2013 ◽  
Vol 50 (4) ◽  
pp. 435-450 ◽  
Author(s):  
Christopher T.S. Beckett ◽  
Charles E. Augarde
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Soil Water ◽  
Water Retention ◽  
Adsorbed Water ◽  
Retention Data ◽  
Soil Water Retention ◽  
Pore Size Distributions ◽  
Water Retention Properties

Several models have been suggested to link a soil's pore-size distribution to its retention properties. This paper presents a method that builds on previous techniques by incorporating porosity and particles of different sizes, shapes, and separation distances to predict soil water retention properties. Mechanisms are suggested for the determination of both the main drying and wetting paths, which incorporate an adsorbed water phase and retention hysteresis. Predicted results are then compared with measured retention data to validate the model and to provide a foundation for discussing the validity and limitations of using pore-size distributions to predict retention properties.

scholarly journals Conducting Membranes and Coatings made from Redispersable Nanoscaled Crystalline SnO2:Sb Particles

1998 ◽  
Vol 520 ◽  
Author(s):  
C. Goebbert ◽  
M. A. Aegerter ◽  
D. Burgard ◽  
R. Nass ◽  
H. Schmidt
Keyword(s):  
Thermal Treatment ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Sol Gel ◽  
Total Porosity ◽  
Solid Content ◽  
Visible Range ◽  
Inorganic Membranes ◽  
Separation Processes

ABSTRACTInorganic membranes prepared by the sol gel method are promising candidates for use as filters in separation processes. Conducting supported membranes and coatings have been produced from redispersable nanoscaled crystalline Sb-doped SnO2 powders with a Sb content up to 5 mole % (with respect to Sn). The crystalline particles are monosized (≅4 nm) and fully redispersable in aqueous solution at pH ≥ 8 with a solid content up to 70 wt. %. By thermal treatment at different temperatures and times, the pore size diameter of the material can be adjusted from 4 to 20 nm with a very narrow pore size distribution (∼ ±1 nm) and a total porosity of 63 %, practically independent of the sintering parameters. Uniaxial pressed substrates present similar characteristics with however larger pore size distribution (±5 nm) and 80 % total porosity. Their resistance decreases with sintering temperature and time down to 4 Ω (800 °C 8 h). Fully dispersed aqueous solutions of the powder (25 wt. %) were used to prepare transparent conducting coatings on glass or ceramics by spin-coating. After thermal treatment (1 hour at 550 °C) single layers 200 nm thick exhibited a typical specific electrical resistance ρ = 2.5·10−2 ωcm with transmission in the visible range measured against air of 90%.

scholarly journals COMPUTER SIMULATION OF RANDOM PACKINGS FOR SELF-SIMILAR PARTICLE SIZE DISTRIBUTIONS IN SOIL AND GRANULAR MATERIALS: POROSITY AND PORE SIZE DISTRIBUTION

Fractals ◽  
2014 ◽  
Vol 22 (03) ◽  
pp. 1440009 ◽  
Author(s):  
MIGUEL ANGEL MARTÍN ◽  
FRANCISCO J. MUÑOZ ◽  
MIGUEL REYES ◽  
F. JAVIER TAGUAS
Keyword(s):  
Computer Simulation ◽  
Particle Size ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Total Porosity ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Self Similar ◽  
Random Packings

A 2D computer simulation method of random packings is applied to sets of particles generated by a self-similar uniparametric model for particle size distributions (PSDs) in granular media. The parameter p which controls the model is the proportion of mass of particles corresponding to the left half of the normalized size interval [0,1]. First the influence on the total porosity of the parameter p is analyzed and interpreted. It is shown that such parameter, and the fractal exponent of the associated power scaling, are efficient packing parameters, but this last one is not in the way predicted in a former published work addressing an analogous research in artificial granular materials. The total porosity reaches the minimum value for p = 0.6. Limited information on the pore size distribution is obtained from the packing simulations and by means of morphological analysis methods. Results show that the range of pore sizes increases for decreasing values of p showing also different shape in the volume pore size distribution. Further research including simulations with a greater number of particles and image resolution are required to obtain finer results on the hierarchical structure of pore space.

scholarly journals Water Retention and Pore Size Distribution of a Biopolymeric-Amended Loam Soil

2019 ◽  
Vol 18 (1) ◽  
pp. 0 ◽  
Author(s):  
Mehdi Rahmati ◽  
Andreas Pohlmeier ◽  
Sara Mola Ali Abasiyan ◽  
Lutz Weihermüller ◽  
Harry Vereecken
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Water Retention ◽  
Loam Soil

scholarly journals The effect of porosity on the reactivity of calcium sorbents

Mineralogia ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 37-45
Author(s):  
Michał Wichliński ◽  
Rafał Kobyłecki
Keyword(s):  
Specific Surface ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Total Porosity ◽  
Classical Procedure ◽  
Reactivity Indexes ◽  
Capacity Index

Abstract The current work presents the results of seven sorbent samples investigated with respect to SO2 capture. The sorbents’ reactivity and capacity indexes were determined, and the tests were carried out in accordance with the ‘classical’ procedure for limestone sorbents. The reactivity indexes (RIs) of the tested samples were in the range of 2.57 and 3.55 (mol Ca)/(mol S), while the absolute sorption coefficients as determined by the capacity index (CI) varied between 87.9 and 120.6 (g S)/(kg of sorbent). Porosimetric analysis was also carried out and the specific surface area of the samples was found to be between 0.2 and 1.7 m2/g. The number of micro-, meso- and macro-pores in individual samples was determined from the corresponding pore size distribution histograms, and the values of sorbent RIs and CIs were correlated with the samples’ total porosity and specific surface.

scholarly journals Hydraulic Properties of Forest Soils with Stagnic Conditions

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1113
Author(s):  
Stefan Julich ◽  
Janis Kreiselmeier ◽  
Simon Scheibler ◽  
Rainer Petzold ◽  
Kai Schwärzel ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Soil Samples ◽  
Stagnant Water ◽  
Infiltration Rates ◽  
Retention Characteristic ◽  
Water Conditions

Tree species, e.g., shallow vs. deep rooting tree species, have a distinct impact on hydrological properties and pore size distribution of soils. In our study, we determined the soil hydrologic properties and pore size distribution at three forest stands and one pasture as reference on soils with stagnant water conditions. All sites are located in the Wermsdorf Forest, where historical studies have demonstrated severe silvicultural problems associated with stagnant water in the soil. The studied stands represent different stages of forest management with a young 25-year-old oak (Sessile Oak (Quercus petraea) and Red oak (Q. robur)) plantation, a 170-year-old oak stand and a 95-year-old Norway Spruce (Picea abies) stand in second rotation. We determined the infiltration rates under saturated and near-saturated conditions with a hood-infiltrometer at the topsoil as well as the saturated hydraulic conductivity and water retention characteristic from undisturbed soil samples taken from the surface and 30 cm depth. We used the bi-modal Kosugi function to calculate the water retention characteristic and applied the normalized Young-Laplace equation to determine the pore size distribution of the soil samples. Our results show that the soils of the old stands have higher amounts of transmission pores, which lead to higher infiltration rates and conductance of water into the subsoil. Moreover, the air capacity under the old oak was highest at the surface and at 30 cm depth. There was also an observable difference between the spruce and oak regarding their contrasting root system architecture. Under the oak, higher hydraulic conductivities and air capacities were observed, which may indicate a higher and wider connected macropore system. Our results confirm other findings that higher infiltration rates due to higher abundance of macropores can be found in older forest stands. Our results also demonstrate that an adapted forest management is important, especially at sites affected by stagnant water conditions. However, more measurements are needed to expand the existing data base of soil hydraulic properties of forest soils in temperate climates.

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