Undercooling, Freezing Point Depression, and Ice Nucleation of Soil Water

1968 ◽  
Vol 6 (3) ◽  
pp. 349-355 ◽  
Author(s):  
Duwayne M. Anderson
Keyword(s):  
Soil Water ◽  
Freezing Point ◽  
Ice Nucleation ◽  
Freezing Point Depression

scholarly journals In vitro uses of biological cryoprotectants

2002 ◽  
Vol 357 (1423) ◽  
pp. 945-951 ◽  
Author(s):  
Peter J. Lillford ◽  
Chris B. Holt
Keyword(s):  
Crystal Growth ◽  
Freezing Point ◽  
Ice Nucleation ◽  
Active Species ◽  
Osmotic Regulation ◽  
Ice Crystal ◽  
Freezing Point Depression ◽  
Commercial Use ◽  
Crystal Growth Inhibition

Ice can be anything from a highly destructive agent in agriculture to a useful building material. Established industries are based on the known rules of physics and chemistry which allow some control of amounts of ice or ice crystal geometry. However, organisms have much more subtle requirements to maintain their delicate internal structure if they are to survive freezing. As a result they have selected specific molecules for freezing–point depression, osmotic regulation, ice nucleation and crystal growth inhibition. All these active species may have potential commercial use once they are identified, understood and produced at economic scales. We examine the progress made so far in extending biological subtlety into commercial processes, and look for prospects for further innovation.

scholarly journals Implementation of salt-induced freezing point depression function into CoupModel_v5 for improvement of modelling seasonally frozen soils

2018 ◽  
Author(s):  
Mousong Wu ◽  
Per-Erik Jansson ◽  
Jingwei Wu ◽  
Xiao Tan ◽  
Kang Wang ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Soil Water ◽  
Field Experiments ◽  
Freezing Point ◽  
Numerical Models ◽  
Soil Freezing ◽  
Freezing Point Depression ◽  
Soil Hydrology ◽  
Cold Regions ◽  
New Model

Abstract. Soil freezing/thawing is important for soil hydrology and water management in cold regions. Salt in agricultural field impacts soil freezing/thawing characteristics and therefore soil hydrologic process. In this context, we conducted field experiments on soil water, heat and salt dynamics in two seasonally frozen agricultural regions of northern China to understand influences of salt on cold regions hydrology. We developed CoupModel by implementing impacts of salt on freezing point depression. We employed a Monte-Carlo sampling method to calibrate the new model with field observations. The new model improved soil temperature mean error (ME) by 16 % to 77 % when new freezing point equations were implemented into CoupModel. Nevertheless, we found that parameters related to energy balance and soil freezing characteristics in the new model were sensitive to soil heat and water transport at both sites. However, a systematic model sensitivity and calibration has shown to be able to improve model performance, with mean values of R2 from behavioral simulations for soil temperature at 5 cm depth as high as 0.87 and 0.90, and mean value of R2 for simulated soil water (liquid or total water contents at 5 cm depth) of 0.31 and 0.80 at site Qianguo and site Yonglian, respectively. This study provided a new approach considering influences of salt on soil freezing/thawing in numerical models and highlighted the importance of salt in soil hydrology of seasonally frozen agricultural soils.

Measurement of the suction of soil water by Portland stone absorbers calibrated by a new method for determining vapour pressures near to saturation

1942 ◽  
Vol 32 (4) ◽  
pp. 413-427 ◽  
Author(s):  
A. L. C. Davidson ◽  
R. K. Schofield
Keyword(s):  
Soil Water ◽  
Vapour Pressure ◽  
Freezing Point ◽  
Salt Content ◽  
Thin Plates ◽  
Freezing Point Depression ◽  
Low Salt ◽  
Dissolved Matter ◽  
Correct Reading ◽  
A New Technique

1. A filter apparatus cannot be relied upon to give a correct reading of the suction of soil water when this exceeds about 400 cm. of water.2. Owing to the contribution of dissolved matter to the freezing-point depression the suction in a soil of normal low salt content can only be obtained from the freezing-point depression with reasonable accuracy when it exceeds about 4000 cm. of water (freezing-point depression greater than 0–3° C).3. Suctions in the range 400 to 4000 cm. have been measured with the aid of calibrated absorbers consisting of thin plates of Portland stone.4. The plates were calibrated up to 1000 cm. by the application of suction through a filter, and above 1000 cm. by measuring the vapour-pressure depression by a new technique.5. When applied direct to soil, the new vapour-pressure technique is more reliable than the freezing-point method, and can be applied to materials which do not exhibit a well-defined freezing-point.6. A suitable soil was washed free from salts and brought to 1000 cm. suction on a filter. Measurements of the vapour-pressure depression and the freezing-point depression checked well with the thermodynamic formulae.

Depression of freezing temperature of water and water solutions in porous materials

1989 ◽  
Vol 54 (10) ◽  
pp. 2644-2647 ◽  
Author(s):  
Petr Schneider ◽  
Jiří Rathouský
Keyword(s):  
Water Vapor ◽  
Porous Materials ◽  
Inorganic Salt ◽  
Freezing Point ◽  
Freezing Temperature ◽  
Inorganic Salts ◽  
Freezing Point Depression ◽  
Salt Solutions ◽  
Water Solutions

In porous materials filled with water or water solutions of inorganic salts, water freezes at lower temperatures than under normal conditions; the reason is the decrease of water vapor tension above the convex meniscus of liquid in pores. The freezing point depression is not very significant in pores with radii from 0.05 μm to 10 μm (about 0.01-2.5 K). Only in smaller pores, especially when filled with inorganic salt solutions, this depression is important.

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