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Full-Text Articles in Physical Sciences and Mathematics
The Influence Of Thermo-Gradients Upon Water Movement And Retention In Unsaturated Soils, Jose V. Salazar
The Influence Of Thermo-Gradients Upon Water Movement And Retention In Unsaturated Soils, Jose V. Salazar
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Temperature differences of about 5, 10, and 15 V, were applied to uniformly packed and insulated horizontal column of Millville silt loam soil using mean temperatures near 13, 14, 15, 16, 17, 18, 19, 20 and 23.5 C. The temperature distribution along the soil column was determined using copper constantan thermocouples. Soil samples were taken to determine volumetric moisture content, and soil water potential, using the vapor pressure psychometer technique. The thermodynamic flow equation of Taylor and Cary, (1964) was used to calculate the hydro-thermal transfer coefficient (ß) as given by:
-ß = d(μw)T / dlnT
where …
Movement Of Atrazine In Soil Under Furrow Irrigation, Jyothi Veerabhadrappa
Movement Of Atrazine In Soil Under Furrow Irrigation, Jyothi Veerabhadrappa
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Movement of atrazine in response to furrow irrigations was studied using the samples of Timpanogos silt loam soil. Distribution in soil profile of surface applied herbicide was determined by drawing samples of water extracts through porous cylinders. Atrazine quantity was determined by spectrophotometer.
It was observed that the herbicide found in the water extracts was an indication of the quantity present in the soil. The herbicide moved readily with the applied water. Irreversible thermodynamic model could not be applied because of the initial and final boundary conditions. The pattern of movement was in conformity with the chromatographic theory.
Simultaneous Movement Of Water And Herbicides In Unsaturated Soils, Ming-Shyong Yang
Simultaneous Movement Of Water And Herbicides In Unsaturated Soils, Ming-Shyong Yang
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Since weed killers were developed in the early part of the decade beginning in 1940, herbicides have been increasing in use until they are now widely used to control weeds. The application of herbicides has thus become a regular agricultural and ecological practice.
An Application Of A Thermodynamic Flow Equation To Water Movement In Unsaturated Soil, Brennan Derry Soane
An Application Of A Thermodynamic Flow Equation To Water Movement In Unsaturated Soil, Brennan Derry Soane
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The movement of water in soil presents many interesting problems to the research worker. It is also a subject which finds wide and important application in agriculture and several branches of engineering.
The object of this work was to examine the usefulness of a new equation of flow of water in unsaturated soil. If valid, this new approach may be able to eliminate some of the gaps in our present knowledge of the subject.
All soil lying above the capillary fringe of a water table is in the unsaturated state with respect to water. This means that in any macroscopic …