On The Dynamics Of Canopy Resistance: Generalized
Linear Estimation And Relationships With Primary
Micrometeorological Variables,
2010
University of Nebraska-Lincoln
On The Dynamics Of Canopy Resistance: Generalized Linear Estimation And Relationships With Primary Micrometeorological Variables, Suat Irmak, Denis Mutiibwa
Department of Agricultural and Biological Systems Engineering: Faculty Publications
The 1‐D and single layer combination‐based energy balance Penman‐Monteith (PM) model has limitations in practical application due to the lack of canopy resistance (rc) data for different vegetation surfaces. rc could be estimated by inversion of the PM model if the actual evapotranspiration (ETa) rate is known, but this approach has its own set of issues. Instead, an empirical method of estimating rc is suggested in this study. We investigated the relationships between primary micrometeorological parameters and rc and developed seven models to estimate rc for a nonstressed maize canopy on an hourly …
Water And Nutrient Balances Of Vegetative Treatment Systems For Feedlots In South Dakota,
2010
South Dakota State University
Water And Nutrient Balances Of Vegetative Treatment Systems For Feedlots In South Dakota, Daniel T. Ostrem
Electronic Theses and Dissertations
Vegetative treatment systems (VTS) are a possible alternative to storage basins for managing feedlot runoff but have not been researched in South Dakota. This study was conducted to evaluate the performance of VTS within South Dakota. The performance was evaluated by determining water and mass balances on each vegetative treatment area (VTA). The balances were determined by measuring all inflow, outflow, evapotranspiration, precipitation, and both soil and water nutrient concentrations within the VTA. Twelve site years have been completed in researching VTS from four feed lots in South Dakota. Seven of the twelve site-years VTS were able to prevent water …
A Continuous Mathematical Model Of The One-Dimensional Sedimentation Process Of Flocculated Sediment Particles,
2010
University of Kentucky
A Continuous Mathematical Model Of The One-Dimensional Sedimentation Process Of Flocculated Sediment Particles, Sebastian Fernando Torrealba
University of Kentucky Doctoral Dissertations
A new continuous one-dimensional sedimentation model incorporating a new continuous flocculation model that considers aggregation and fragmentation processes was derived and tested. Additionally, a new procedure to model sediment particle size distribution (PSD) was derived. Basic to this development were three different parametric models: Jaky, Fredlund and the Gamma probability distribution (GPD) were chosen to fit three different glass micro-spheres PSDs having average particle sizes of 7, 25 and 35 microns. The GPD provided the best fit with the least parameters. The bimodal GPD was used to fit ten sediment samples with excellent results (< 5% average error). A continuous flocculation model was derived using the method of moments for solving the continuous Smoluchowski coagulation equation with fragmentation. The initial sediment PSD was modeled using a bimodal GPD. This new flocculation model resulted in a new general moments’ equation that considers aggregation and fragmentation processes, which is represented by a system of ordinary differential equations. The model was calibrated using a genetic algorithm with initial and flocculated PSDs of four sediment samples and four anionic polyacrylamides flocculants. The results show excellent correlation between predicted and observed values (R2 > 0.9878). A new continuous …
