Liquid limit of soils from equilibrium water content in one-dimensional normal compression

Hydraulic conductivity of sand-bentonite (SB) backfills amended with polyanionic cellulose (PAC) to lead nitrate (Pb(NO3)2) solutions was evaluated experimentally in this study. PAC-amended sand-bentonite (PSB) backfills were synthesized by mixing sand-bentonite mixture with 0.3 to 1.2% dry PAC (by total dry mixture mass) and mixed with a certain weight of conventional bentonite (CB) slurry. The rheology properties including the filtrate loss, viscosity, density, and pH testes of slurry with various bentonite dosages were measured to determine the reasonable CB dosage of slurry. The slump tests on PSB backfills with various mass slurries were conducted to determine the corresponding water content of backfills with slump 125 ± 5 mm. Under the applied pressure 100 kPa, the hydraulic conductivity to Pb(NO3)2 solutions (kc) of PSB backfills with various PAC contents was evaluated based on the modified filter press (MFP) tests, to ascertain the optimum PAC content of PSB backfills when permeated with Pb(NO3)2 solutions. Index properties, including the specific gravity (Gs) and liquid limit (wL) of PSB backfills, were measured after MFP tests. The MFP tests for PSB backfills were then conducted under various applied pressures to obtain the relationship between void ratio (e) and hydraulic conductivity of backfills. Finally, the flexible-wall permeability test (FWP test) under osmotic pressure 100 kPa was conducted to verify the effectiveness of the MFP test. The results indicate that slurry with 8% bentonite dosage is the reasonable choice in slurry wall construction. PSB has lower GS and higher wL compared to SB; increasing Pb concentration leads to GS of PSB increased and wL of PSB decreased. PSB with 0.6% PAC content is supposed as the optimum proportion of backfills when permeated with concentrated Pb(NO3)2 solution. PAC adsorbs large amount of bound water, which leads to higher water content (w) and e of PSB backfills, while lead ions (Pb) cause the diffuse double layer (DDL) of bentonite compressed and e of PSB backfills reduced. The kc of PSB-0.6 remains lower than 10−9 m/s and increases less than 10 times though the Pb concentration was up to 500 mM, demonstrating that the hydraulic performance of backfills can be improved effectively in Pb(NO3)2 solution by the additive PAC. The comparison results between k from MFP tests and FWP tests show that the MFP test is an effective and easy evaluation of hydraulic conductivity of backfills.

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Test Investigation on Mechanical of Unsaturated Loess

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.204-208.22 ◽

2012 ◽

Vol 204-208 ◽

pp. 22-27

Author(s):

Yan Zhu ◽

Yun Xu Chen

Keyword(s):

Water Content ◽

Horizontal Plane ◽

Mechanical Characteristics ◽

Loess Soil ◽

Dry Density ◽

One Dimensional ◽

Test Investigation ◽

Unsaturated Loess ◽

Test Result ◽

Compacted Loess

Compression and collapse of unsaturated compacted loess are studied by using dry density and water content which easily controlled in engineering, the controlling range of dry density and water content are confirmed respectively. Then the deformation of compression and collapse and the frequency of engineering damager occurrence can be decreased. In addition, the mechanical characteristics of loess in different directions may differ because the loess was consolidated only under the condition of its upper weight of soil and load. The conventional mechanical experiments, including one-dimensional compress and collapse test, were conducted with the specimen of loess soil in different angle from the original horizontal plane. The test result shows that the loess is anisotropic

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Importance of water content and motion in the one-dimensional conductorK2Pt(CN)4Cl0.3·nH2O

Physical Review B ◽

10.1103/physrevb.10.1778 ◽

1974 ◽

Vol 10 (5) ◽

pp. 1778-1783 ◽

Cited By ~ 17

Author(s):

M. A. Butler ◽

H. J. Guggenheim

Keyword(s):

Water Content ◽

One Dimensional ◽

The One

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Experimental Determination of the Equilibrium Water Content of CO2 at High Pressure and Low Temperature

Journal of Chemical & Engineering Data ◽

10.1021/acs.jced.5b00320 ◽

2015 ◽

Vol 60 (9) ◽

pp. 2674-2683 ◽

Cited By ~ 5

Author(s):

Louis V. Jasperson ◽

Jeong Won Kang ◽

Chul Soo Lee ◽

Don Macklin ◽

Paul M. Mathias ◽

...

Keyword(s):

High Pressure ◽

Low Temperature ◽

Experimental Determination ◽

Water Content ◽

Equilibrium Water Content

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Equilibrium Water Content Measurements For Acid Gas Mixtures

Acid Gas Injection and Related Technologies ◽

10.1002/9781118094273.ch1 ◽

2011 ◽

pp. 3-20 ◽

Cited By ~ 1

Author(s):

R. A. Marriott ◽

E. Fitzpatrick ◽

F. Bernard ◽

H. H. Wan ◽

K. L. Lesage ◽

...

Keyword(s):

Water Content ◽

Gas Mixtures ◽

Equilibrium Water Content ◽

Acid Gas

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Evaluations of the effects of soil properties and electrical conductivity on the water content reflectometer calibration for landfill cover soils

Soil and Water Research ◽

10.17221/158/2015-swr ◽

2017 ◽

Vol 12 (No. 1) ◽

pp. 10-17 ◽

Cited By ~ 1

Author(s):

K. Kim ◽

J. Sim ◽

T.-H. Kim

Keyword(s):

Electrical Conductivity ◽

Soil Properties ◽

Water Content ◽

Clay Content ◽

Liquid Limit ◽

Time Domain Reflectometry ◽

Volumetric Water Content ◽

Unit Weight ◽

Landfill Cover ◽

Dry Unit Weight

This study presents soil-moisture calibrations using low-frequency (15–40 MHz) time domain reflectometry (TDR) probe, referred to as water content reflectometer (WCR), for measuring the volumetric water content of landfill cover soils, developing calibrations for 28 different soils, and evaluating how WCR calibrations are affected by soil properties and electrical conductivity. A 150-mm-diameter PVC cell was used for the initial WCR calibration. Linear and polynomial calibrations were developed for each soil. Although the correlation coefficients (R<sup>2</sup>) for the polynomial calibration are slightly higher, the linear calibrations are accurate and pragmatic to use. The effects of soil electrical conductivity and index properties were investigated using the slopes of linear WCR calibrations. Soils with higher electrical conductivity had lower calibration slopes due to greater attenuation of the signal during transmission in the soil. Soils with higher electrical conductivity tended to have higher clay content, organic matter, liquid limit, and plasticity index. The effects of temperature and dry unit weight on WCR calibrations were assessed in clayey and silty soils. The sensor period was found to increase with the temperature and density increase, with greater sensitivity in fine-textured plastic soils. For typical variations in temperature, errors in volumetric water content on the order of 0.04 can be expected for wet soils and 0.01 for drier soils if temperature corrections are not applied. Errors on the order of 0.03 (clays) and 0.01 (silts) can be expected for typical variations in dry unit weight (± 2 kN/m<sup>3</sup>).

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Isotherms and isostatic heat of foam-mat dried yellow mombin pulp

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v22n6p436-441 ◽

2018 ◽

Vol 22 (6) ◽

pp. 436-441

Author(s):

Maisa D. Cavalcante ◽

Geovana R. Plácido ◽

Daniel E. C. de Oliveira ◽

Bheatriz S. M. de Freitas ◽

Caroline Cagnin ◽

...

Keyword(s):

Water Content ◽

Water Activity ◽

Nutritional Value ◽

Isosteric Heat ◽

Agricultural Products ◽

Equilibrium Water Content ◽

Desorption Isotherms ◽

Forced Air ◽

Semi Solid ◽

Content Range

ABSTRACT Yellow mombin has high nutritional value but is very perishable. Foam mat drying is a method that has been widely used to preserve liquid and semi-solid powdered foods. In this context, the aim of this study was to determine desorption isotherms and isosteric heat of yellow mombin (Spondias mombin L.) foam for different conditions of temperature and water activity. Powdered yellow mombin pulp was obtained by drying in forced-air oven regulated to 60 ° C. The indirect static method was used to determine the isotherms and isosteric heat, whereas water activity (aw) was determined using the Hygropalm-HP23AW-A analyzer. A B.O.D. incubator, set at 10, 20, 30 and 40 °C, was used to control the temperature, and the water activity for each temperature was between 0.220 and 0.832. The experimental data were fitted to mathematical models frequently used to represent the hygroscopicity of agricultural products, and the best model was the Modified Halsey. Integral isosteric heat of desorption of yellow mombin powder, within the water content range of 17.22 to 57.58 (% d.b.), ranged from 3198.56 to 2598.38 kJ kg-1. It was concluded that the equilibrium water content of yellow mombin pulp powder increased with the increment in water activity; desorption isotherms obtained for yellow mombin pulp powder showed sigmoid form and, with the reduction of water content, the isosteric heat increases.

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