Engineering Commons^™

Finite Element Model Of Nitrogen Species Transformation And Transport In The Unsaturated Zone, Jagath J. Kaluarachchi, J. C. Parker

Civil and Environmental Engineering Faculty Publications

A two-dimensional finite element model based on Galerkin's weighted residual approach and incorporating an upstream weighting technique was developed to predict the simultaneous transformation and transport of nitrogen species. The nitrogen cycle used in the analyses assumes first-order rate coefficients for nitrification, denitrification, immobilization and mineralization between the nitrogen species NH +4, NO -3, organic-N and denitrified fractions. The NO -3-N component in the soil solution was assumed to have negligible adsorption on exchange sites while adsorption of NH +4 was assumed to be represented by a Freundlich type nonlinear isotherm ( S = kdCp). The accuracy and validity of …

Development Of A Combined Quantity And Quality Model For Optimal Unsteady Groundwater Management, Richard C. Peralta, J. Solaimanian, C. L. Griffis

Civil and Environmental Engineering Faculty Publications

Presented are alternative techniques for including conservative solute transport within computer models for optimizing groundwater extraction rates. Unsteady two-dimensional flow and dispersed conservative solute transport are assumed. Comparisons are made of the practicality of including modified forms of implicit and explicit finite difference solute transport equations within optimization models. These equations can be calibrated and subsequently used within a MODCON procedure. The MODCON modelling procedure consists of an integrated series of five optimization or simulation modules. The procedure is applicable for either an entire aquifer system or for a subsystem of a larger system. The first module, A, computes physically …

Maximizing Reliable Crop Production In A Dynamic Stream/Aquifer System, Richard C. Peralta, K. Kowalski, R. R.A. Cantiller

Civil and Environmental Engineering Faculty Publications

A procedure for planning the optimal spatial distribution of crops to be reliably irrigated by conjunctive use of water resources is presented. The implicitly stochastic procedure utilizes. simulation/ optimization model of • stream/ aquifer system. The model utilizes linear optimization, hydrologic influence coefficients and time-varying crop water production functions. It appropriately simulates the time variant, interdependent responses of groundwater levels, stream nap and stream/aquifer interflow to groundwater pumping, and diversion of river water to nonriparian lands. It determines the temporally and spatially varying distribution of groundwater and diverted river water that should be utilized In order to maximizing annual crop …

Optimal Conjunctive Use-Sustained Yield Pumping Analysis For Eastern Arkansas, Rosalinda R.A. Cantiller, Richard C. Peralta, Hossein Azarmnia

Civil and Environmental Engineering Faculty Publications

The likelihood that irrigated agricultural acreages will increase in eastern Arkansas is high. This results from favorable agricultural soils, climate, and the availability of significant water resources.

Measurement And Simulation Of One-Dimensional Transient Three Phase Flow For Monotonic Liquid Drainage, R. J. Lenhard, J. Dane, J. C. Parker, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

Simultaneous movement of oil, water, and air in a sandy porous medium was investigated experimentally under transient flow conditions and results were compared to numerical simulations employing a finite element multiphase flow code. The liquid hydrocarbon was Soltrol 170, a low-density branched alkane mixture. Liquid saturations were measured using a collinear dual-energy gamma radiation apparatus and liquid pressures were measured using hydrophilic (untreated) and hydrophobic (treated) ceramic tensiometers connected to pressure transducers. The experimental regime was selected to impose monotonically draining water and total liquid saturation paths to avoid hysteretic effects. Measured saturations and pressures are compared to values obtained …

Bioavailable Phosphorus In The Bear River System, Utah, Kenneth Warren Barker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The bioavailable fraction of phosphorus (BAP) in the lower Bear River system waters was investigated. BAP plays a critical role as the limiting nutrient for algal production and eutrophication in proposed reservoirs in the Bear River system. The Bear River system has a hardness ranging between 180-240 mg/L as CaCO₃ which significantly affects BAP.

BAP estimation was done by a modified Selenastrum capricornutum Printz Algal Assay Bottle Test. The algal bioassay is considered the best estimator of BAP because no chemical tests or indicator parameters are available. Autoclaving and UV radiation were found to be unacceptable means for sterilization …

Evaluation Of Spatially-Distributed Snowpack Estimation Using Pattern Recognition, Cheng-Hua Leu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A procedure for spatially-distributed snowpack estimate is proposed and evaluated herein. This procedure is divided into two parts, off-line and on-line parts. The off-line procedure uses Fuzzy c-Varieties (FCV) algorithms to perform the watershed classification based on Landsat TM data and a digital elevation model and estimate influence coefficient for all pixels in the watershed. Through the concept of influence coefficient, a set of prototypical points can be selected and located. The on-line procedure estimates snowpack properties at these prototypical points and then transforms them to estimates of snowpack properties at any point in the watershed. To effectively evaluate this …

A Hydrological Characterization Of A Zero-Order Basin In Volcanic Hillslope Terrain, Neil A. Mock

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hydrologists have displayed a renewed effort towards understanding the complexity of runoff generation and its association with basin structure. Basin structure is defined as the complex geomorphological, vegetation, and soil characteristics that make up and distinguish the physical nature of a drainage basin. Zero-order basins are an integral part of watershed structure because they furnish the capacity to store and transmit snowmelt and rainfall. By definition, zero-order basins are sub-basins which are depressions in the surf ace and shallow bedrock topography. This study involves a space time characterization of a zero-order basin in fractured media located in southwest Idaho.

The …

Great Salt Lake Interisland Diking: Water Quality Considerations, Executive Summary, Utah Water Research Laboratory, J. P. Riley, J. I. Blandamer, W. J. Doucette, R. R. Dupont, A. W. Grover, J. Herrick, J. M. Ihnat, J. E. Mclean, M. W. Nath, S. R. Rushforth, J. L. Sims, R. C. Sims, W. A. Wurtsbaugh

Reports

No abstract provided.

Vilma (Virtually Interactive Large Scale Model For Arkansas), Rosalinda R.A. Cantiller, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

This user’s guide supports the use of VILMA (Virtually Interactive Large-scale Model for Arkansas). This document presents the basic concepts in Chapter I. Chapter II discusses the execution steps that the user follows during a VILMA session. Chapter III provides a detailed illustration of example data files. Chapter IV presents two example VILMA sessions. Finally, Chapter V elaborates on additional concepts. The Appendices consist of relevant program listings, instructions, and example files. In this user’s guide, the word "interactive" means the user enters his responses to the prompts that appear on a computer terminal while he is logged on to …

Fate And Transport Of Organics In Soil: Model Predictions And Experimental Results, B. D. Symons, Ronald C. Sims, W. J. Grenney

Biological Engineering Faculty Publications

Laboratory batch reactors were used to generate quantitative information about the fate of polynuclear aromatic hydrocarbon (PNA) compounds in soil systems. First-order degradation rates and equilibrium partition coefficients determined in laboratory studies were used in the Vadose Zone Interactive Processes (VIP) mathematical model to predict the fate and behavior of the PNA compounds as a function of time and soil depth. Predicted model results were compared with independent laboratory soil column studies for model validation. The VIP model provided a good approximation of the degradation and transport of the seven PNA compounds evaluated after 6 months of incubation in soil. …

Biological Transformation And Detoxification Of 7,12-Dimethylbenzanthracene In Soil, K. Park, Ronald C. Sims, W. J. Doucette, J. E. Matthews

Biological Engineering Faculty Publications

Biological transformation and detoxification of 7,12-dimethylbenz(a)anathracene (DMBA) were studied in a nonacclimated sandy loam soil. Parent 14C DMBA biodegraded extensively (62% to 20%), accompanying an increase of metabolite 14C fraction (4% to 53%). Incorporation of DMBA into non extractable soil residue ,4C increased from 12 to 17%, but the increase was not statistically significant. DMBA was transformed into several metabolic products in the soil system, including 4-hydroxy-, 5-hydroxy-, and 10-hydroxy-DMBA and 7,12-dihydro 12-methyl-7-methylene-benz(a)anthracene-12-ol. High polarity transformation products of DMBA demonstrated a negative mu tagenic response with the Ames mutagenicity assay, strain TA 100, for both low and neutral pH soils. …

Human Health Effects Assays, Ronald C. Sims, J. L. Sims, R. R. Dupont

Biological Engineering Faculty Publications

Environmental health risk assessments based upon animal study results, epidemiology, quantitative structure activity relationships (QSARs), dose-response relationships, risk perception, and expert systems approaches, and the evaluation of mechanisms of carcinogenesis represent the focus for 1987. The term "biological risk assessment" was discussed by Clayson¹ to describe that part of risk assessment concerned with the relevance of specific animal results to the induction of human cancer. Guidelines for health assessment of suspect developmental toxicants addressed evaluation of data from animal testing studies.² Animal toxicity data on 200 chemicals and epidemiologic data on 30 chemicals was included within a data …

Stochastic Interpolation Of Precipitation Data From Multiple Sensors, D. J. Seo, A. Azimi-Zonooz, D. S. Bowles, W. F. Krajewski, C. J. Duffy, K. P. Georgakakos, T. H. Lee

Reports

Introduction: This report summarizes the work conducted under Grant No. ECE-8419189, "Stochastic Interpolation of Precipitation Data from Multiple Sensors," which was awarded to Utah State University in September, 1985, and completed February 29, 1988. it also covers work under a supplemental award made in February, 1986. The final report is organized into four sections. The following section presents the objective of the research and a brief problem statment. Section 3 contains a summary of second-year work including the project team, work plan, work completed, and publications. In Section4, project conclusions are summarized. A summary of on-going future work is given …

Great Salt Lake Interisland Diking: Water Quality Considerations, John I. Blandamer, William J. Doucette, Ryan R. Dupont, Anthony W. Grover, James Herrick, Jean M. Ihnat, Joan E. Mclean, Michael W. Nath, Samuel R. Rushforth, Judith L. Sims, Ronald C. Sims, Wayne A. Wurtsbaugh

Reports

No abstract provided.

Friction Factor Tests On High Density Polyethylene Pipe, Steven L. Barfuss

Reports

No abstract provided.

Architectural Considerations For Photonic Switching Networks, Harvard S. Hinton

Electrical and Computer Engineering Faculty Publications

Photonic technologies are reviewed that could become important components of future telecommunication systems. Photonic devices and systems are divided into two classes according to the function they perform. The first class, relational, refers to devices, that map the input channels to the output channels under external control. The second class, logic, perform some type or combination of Boolean logic functions. Some of the strengths and weaknesses of operating in the photonic domain are presented. Relational devices and their applications are discussed. Optical logic devices and their potential applications are reviewed.