Record Details
Field | Value |
---|---|
Title | Measurement and interpretation of physical properties of soils |
Names |
Nagpal, Narender Kumar, 1942-
(creator) Boersma, Larry (advisor) |
Date Issued | 1971-02-19 (iso8601) |
Note | Graduation date: 1971 |
Abstract | One of many important physical properties that must be known to understand transport phenomena in soils is pore size distribution. Presently the pore size distributions of soils are most commonly obtained from soil water characteristic curves. The soil water characteristic curves are usually obtained by the pressure plate technique. It is a very laborious and time consuming procedure, with questionable reproducibility. Use of the mercury intrusion porosimeter in determining pore size distributions of soils was evaluated. Eight soils differing in clay content were used. Upon applying appropriate computational techniques the two methods were found to give identical results. Adoption of mercury intrusion as a standard laboratory procedure is suggested. Thermal conductivities of three size classes of glass beads, 53-74 μ, 74-105 μ, and 149-210 μ, were predicted using the model developed by de Vries. Predicted and experimental values of thermal conductivity showed good agreement. Since vapor transfer under temperature gradients is one of the components of heat transfer, it was hypothesized that pore size distribution by its controlling action on vapor flow would affect the thermal conductivity of the media. The results showed no influence of pore size distribution on thermal conductivity. It was observed however that pore size distribution does affect the rate of water loss from porous beds subjected to diurnal temperature fluctuations. Smaller pores resist rapid loss of water vapor and as a result total heat exchanged in beds made up of small particles was much smaller than observed for beds made up of large particles. The evaporative flux constitutes a major part of the total heat flux. Incoming radiation was observed to be used more efficiently in moist samples than in dry samples. |
Genre | Thesis/Dissertation |
Topic | Soil mechanics |
Identifier | http://hdl.handle.net/1957/46076 |