Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 28 for “"unsaturated flow"”.
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A numerical investigation of unsaturated flow
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1988.
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Parameter estimation for unsaturated flow models
The estimation of parameters in models for soil unsaturated hydraulic properties from transient flow experiments via inversion of the governing initial-boundary value problem is examined. Emphasis is on the estimation of parameters from in-situ experiments where available data are in the form of …
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Investigation and modeling of unsaturated flow through swelling soils
Although the theory of water movement through an unsaturated, swelling soil has been developing for a number of years, the efficiency of the results has been limited, and the developed models have suffered from a lack of a mechanism to reliably define water flow and experimental techniques for …
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An evaluation of unsaturated flow models in an arid climate
… study was to evaluate the effectiveness of two unsaturated flow models in and regions. The area selected for the study was the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site in Nye County, Nevada. The two models selected for this evaluation were HYDRUS-1D [Simunek et …
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A Fourier finite element model for unsaturated flow in porous media
… the partial differential equation governing the unsaturated flow of water in porous media is developed and applied to approximate the hydraulic head and to solve for the flux functions that obey the one-dimensional unsaturated flow equation. The algorithms are based on a Fourier finite element …
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Large-scale models of transient unsaturated flow and contaminant transport using stochastic methods
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1984.
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Development of unsaturated flow functions for low impact development stormwater management systems filter media and flow routines for hydrological modeling of permeable pavement systems
… appropriate equations for representing different flow components of LID systems are investigated. Special attention was given to modeling water routing through the filter media layers of LID systems. The water movement through a permeable pavement system was monitored for over a year and it was …
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Numerical modelling of transport of pollutant through soils
… contaminant through soils involves analyses of unsaturated and saturated flow of water and advective dispersive transport of contaminant species. A finite element model is developed here for such an analysis. It is based on the transient nonlinear Richard's equation for the unsaturated flow and …
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Αναλυτική επίλυση μη γραμμικών προβλημάτων διήθησης
… ONE DIMENSIONAL HORIZONTAL WATER ABSORPTION IN UNSATURATED SOILS WITH CONSTANT FLUX BOUNDARY CONDITION. THE GENERAL DIFFERENTIAL EQUATION OF THE ONE DIMENSIONAL UNSATURATED FLOW IS FORMED HAVING THE FLUX AS DEPENDENT VARIABLE WHILE THE TIME T AND THE MOISTURE Θ ARE THE INDEPENDENT VARIABLES. …
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Three-dimensional finite element modeling of steady state seepage using the computer program 'SEEPS3D'
… has been presented in this study. The theory of unsaturated flow has been used in the analysis of steady state seepage. The model applies the invariant mesh procedure in the finite element analysis. Galerkin's method is used in the formulation of the finite element equations. The pre and the post …
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Approximate analytical solutions for modeling subsurface flow
Equations of subsurface flow of water, the Richards equation and the Boussinesq equation, have no known exact analytical solutions. Approximate analytical solutions to these equations have been developed under linearizing simplifications. In the first part of the dissertation two commonly used …
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One dimensional pollutant transport model
… developed. The numerical model is based on the flow and mass transport equations and the finite element method has been used for its formulation. The problem involves unsaturated flow and convective dispersive transport of a contaminant species. A literature survey on the evaluation of the …
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Mathematical Modeling of the Movement of Heat, Water, and Solutes in Two-Dimensional, Saturated-Unsaturated, Surface Water - Groundwater Flow Systems
… A two-dimensional, cross-sectional, saturated-unsaturated, finite difference model for simulating the movement of water, heat, and solutes in surface water-groundwater flow systems was developed. The model has been verified by comparison with analytical solutions and field results. The model …
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MONITORING INFILTRATION FROM NATURAL STORMS USING TIME-LAPSE ELECTRICAL RESISTIVITY TOMOGRAPHY
… characterization of the heterogeneity of flow through the unsaturated zone especially when compared to point measurements taken within the same survey area. The most powerful tool for understanding the unsaturated zone is a combination of several techniques. Many models of unsaturated zone …
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Characterizing and modeling the hydrologic properties of coal combustion by-products in landfills
… focused on determination of the saturated and unsaturated hydraulic properties of fly ash and bottom ash to then be used in order to develop a 1-dimensional unsaturated flow model. Ash samples from a power plant as well as core samples from buried CCB pits were collected for laboratory …
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Hydraulic properties of asphalt concrete
This research has applied standard unsaturated flow models and laboratory methods common to soil analysis, to characterize the hydraulic properties of asphalt concrete. Wetting and drying water characteristic curves were measured for six asphalt concrete cores. From the water characteristic curves, …
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VOID STRUCTURE, COLLOID AND TRACER TRANSPORT PROPERTIES OF STRATIFIED POROUS MEDIA
… scope of the model's predictive capabilities. Flow and transport behaviour was examined in laboratory sand columns of various depths. These experiments examined unsaturated flow of water and conservative solute tracer transport through homogeneous sand samples. Flow through these was not …
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A Hydropedological Approach to Describing Runoff Generation, Lateral Podzolization, and Spatial and Temporal Patterns of DOC in a Headwater Catchment
… catchment. By examining water table records and unsaturated water potential from tensiometers we found that lateral unsaturated flow regimes may be partially responsible for the patterns of lateral translocation observed in HPUs. Finally, the third chapter identifies two HPUs in the catchment as …
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Multiphase flow and mass transport through porous media
… Such problems always involve the multiphase flow and mass transport through three phases, namely air, oil, and water. A finite element model is developed in this thesis based on the theory of multiphase flow weakly-coupled with the theory of mass transport, in a three-dimensional setting. …
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