Physical definition of residual water content in unsaturated soils

The air permeability coefficient has a high correlation with the water content of municipal solid waste. In this study, continuous drying methodology using a tension meter was employed to construct the soil water characteristic curve of municipal solid waste (M-SWCC). The municipal solid waste air permeability test was conducted by a newly designed apparatus. The measured M-SWCC was well reproduced by the van Genuchten (V-G) model and was used to predict the parameters of typical points in M-SWCC, including saturated water content, field capacity, residual water content and water content at the inflection point. It was found that the M-SWCC was significantly influenced by void ratio. The final evaporation and test period of M-SWCC increase with the increase in void ratio of municipal solid waste. The evolution of air permeability coefficient with water content of municipal solid waste depicted three distinct characteristic stages. It was observed that the water contents that corresponded to the two cut-off points of the three stages were residual water content and water content at the inflection point, respectively. The air permeability coefficient of municipal solid waste decreased with the increase of the water content from zero to the residual water content. The air permeability coefficient was almost invariable when the water content increased from residual water content to the water content at the inflection point. When the water content of municipal solid waste exceeded the water content at the inflection point, the air permeability coefficient sharply decreased with the increase of water content.

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Effects of residual suction and residual water content on the estimation of permeability function

Geoderma ◽

10.1016/j.geoderma.2017.05.019 ◽

2017 ◽

Vol 303 ◽

pp. 165-177 ◽

Cited By ~ 25

Author(s):

Qian Zhai ◽

Harianto Rahardjo ◽

Alfrendo Satyanaga

Keyword(s):

Water Content ◽

Residual Water ◽

Residual Water Content ◽

Permeability Function

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Effect of the residual water content in gels on solution combustion synthesis temperature

Journal of Sol-Gel Science and Technology ◽

10.1007/s10971-019-05189-8 ◽

2019 ◽

Vol 93 (2) ◽

pp. 251-261 ◽

Cited By ~ 8

Author(s):

Sh. M. Khaliullin ◽

V. D. Zhuravlev ◽

V. G. Bamburov ◽

A. A. Khort ◽

S. I. Roslyakov ◽

...

Keyword(s):

Water Content ◽

Combustion Synthesis ◽

Solution Combustion Synthesis ◽

Synthesis Temperature ◽

Residual Water ◽

Solution Combustion ◽

Residual Water Content

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The right approach how to design the conditioning system of a sugar silo

Sugar Industry ◽

10.36961/si18649 ◽

2017 ◽

pp. 476-480

Author(s):

Jörg Linek ◽

Norbert Rösch

Keyword(s):

Water Content ◽

Energy Efficient ◽

Weather Conditions ◽

Air Distribution ◽

Residual Water ◽

Work Safety ◽

Efficient Operation ◽

Residual Water Content ◽

Heated Air ◽

The Right

In the light of the constantly growing requirements regarding efficiency, work safety and increasing capacities the design of silos and its conditioning systems demands for customer-specific and experience-based approach. After production fresh sugar has a residual water content which can lead to agglomerations during storage. This affects the product quality, discharge and transport from the silo and endangers staff who has to remove cakings manually. Therefore it is necessary to prepare and distribute the air constantly at optimal conditions. Time of conditioning, air quantity and humidity are the parameters to be determined simultaneously based on the type of silo, residual water content of stored sugar, size of sugar crystals, product feed-in rate and environmental conditions [1]. In the design the amount of water to be removed, air distribution in the sugar bed and temperature are considered. Depending on weather conditions the supplied air is mixed with fresh, dried, cooled or heated air to meet the needed conditions and to enable an energy-efficient operation of the plant.

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Detection and Influence of Residual Water Content on Electrochemical Performance of Solid State Polymer PEO-Litfsi Electrolytes

ECS Meeting Abstracts ◽

10.1149/ma2017-01/3/242 ◽

2017 ◽

Keyword(s):

Solid State ◽

Electrochemical Performance ◽

Water Content ◽

Residual Water ◽

Residual Water Content

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Predicting the permeability function for unsaturated soils using the soil-water characteristic curve

Canadian Geotechnical Journal ◽

10.1139/t94-062 ◽

1994 ◽

Vol 31 (4) ◽

pp. 533-546 ◽

Cited By ~ 445

Author(s):

D.G. Fredlund ◽

Anqing Xing ◽

Shangyan Huang

Keyword(s):

Water Content ◽

Soil Water ◽

Unsaturated Soil ◽

Unsaturated Soils ◽

Characteristic Curve ◽

Degree Of Saturation ◽

Residual Water ◽

Soil Water Characteristic Curve ◽

Coefficient Of Permeability ◽

Permeability Function

The coefficient of permeability for an unsaturated soil is primarily determined by the pore-size distribution of the soil and can be predicted from the soil-water characteristic curve. A general equation, which describes the soil-water characteristic curve over the entire suction range (i.e., from 0 to 106 kPa), was proposed by the first two authors in another paper. This equation is used to predict the coefficient of permeability for unsaturated soils. By using this equation, an evaluation of the residual water content is no longer required in the prediction of the coefficient of permeability. The proposed permeability function is an integration form of the suction versus water content relationship. The proposed equation has been best fit with example data from the literature where both the soil-water characteristic curve and the coefficient of permeability were measured. The fit between the data and the theory was excellent. It was found that the integration can be done from zero water content to the saturated water content. Therefore, it is possible to use the normalized water content (volumetric or gravimetric) or the degree of saturation data versus suction in the prediction of the permeability function. Key words : coefficient of permeability, soil-water characteristic curve, unsaturated soil, water content, soil suction.

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