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Full-Text Articles in Engineering

Two-Zone Transient Storage Modeling Using Temperature And Solute Data With Multiobjective Calibration: 1. Temperature, Bethany T. Neilson, S. C. Chapra, David King Stevens, Christina J. Bandaragoda Dec 2010

Two-Zone Transient Storage Modeling Using Temperature And Solute Data With Multiobjective Calibration: 1. Temperature, Bethany T. Neilson, S. C. Chapra, David King Stevens, Christina J. Bandaragoda

Civil and Environmental Engineering Faculty Publications

This paper presents the formulation and calibration of the temperature portion of a two-zone temperature and solute (TZTS) model which separates transient storage into surface (STS) and subsurface transient storage (HTS) zones. The inclusion of temperature required the TZTS model formulation to differ somewhat from past transient storage models in order to accommodate terms associated with heat transfer. These include surface heat fluxes in the main channel (MC) and STS, heat and mass exchange between the STS and MC, heat and mass exchange between the HTS and MC, and heat exchange due to bed and deeper ground conduction. To estimate …


Two-Zone Transient Storage Modeling Using Temperature And Solute Data With Multi-Objective Calibration: 2. Temperature And Solute, Bethany T. Neilson, David King Stevens, S. C. Chapra, Christina J. Bandaragoda Dec 2010

Two-Zone Transient Storage Modeling Using Temperature And Solute Data With Multi-Objective Calibration: 2. Temperature And Solute, Bethany T. Neilson, David King Stevens, S. C. Chapra, Christina J. Bandaragoda

Civil and Environmental Engineering Faculty Publications

This paper presents the multiobjective calibration results for temperature and solutefrom a two‐zone temperature and solute (TZTS) model which separates transient storageinto surface (STS) and subsurface (HTS) transient storage components. This modelcontains terms associated with surface heat fluxes in the main channel (MC) and STS, heatand mass exchange between the STS and MC, heat and mass exchange between the HTSand MC, and heat exchange due to bed and deeper ground conduction. To estimate theadditional parameters associated with a multiple‐zone model, a data collection effort wasconducted to provide temperature time series and solute tracer curves representingthe movement of heat and/or solute …


Groundwater Stress And Vulnerability In Rural Coastal Aquifers Of The Kalpitiya Peninsula, Sri Lanka, D. Jayasekera, Jagath J. Kaluarachchi, K. Villholth Jun 2010

Groundwater Stress And Vulnerability In Rural Coastal Aquifers Of The Kalpitiya Peninsula, Sri Lanka, D. Jayasekera, Jagath J. Kaluarachchi, K. Villholth

Civil and Environmental Engineering Faculty Publications

Rural coastal aquifers are undergoing rapid changes due to increasing population, high water demand with expanding agricultural and domestic uses, and seawater intrusion due to unmanaged water pumping. The combined impact of these activities is the deterioration of groundwater quality, public health concerns, and unsustainable water demands. The Kalpitiya peninsula located northwest of Sri Lanka is one area undergoing such changes. This land area is limited and surrounded almost completely by sea and lagoon. This study consists of groundwater sampling and analysis, and vulnerability assessment using the DRASTIC method. The results reveal that the peninsula is experiencing multiple threats due …


Bdf-Like Methods For Nonlinear Dynamic Analysis, S. Dong Jan 2010

Bdf-Like Methods For Nonlinear Dynamic Analysis, S. Dong

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

We present several time integration algorithms of second-order accuracy that are numerically simple and effective for nonlinear elastodynamic problems. These algorithms are based on a general four-step scheme that has a resemblance to the backward differentiation formulas. We also present an extension to the composite strategy of the Bathe method. Appropriate values for the algorithmic parameters are determined based on considerations of stability and dissipativity, and less dissipative members of each algorithm have been identified. We demonstrate the convergence characteristics of the proposed algorithms with a nonlinear dynamic problem having analytic solutions, and test these algorithms with several three-dimensional nonlinear …