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Modeling Arsenic Transformation In Clay Soils, Chao-Yi Chung

Theses

This project is designed to estimate the possible transformation forms of arsenic in clay soil. A computer model was established to simulate arsenic transformations. The amount of arsenic species adsorbed, dissolved, and the predominant soluble species are calculated by the model, which is mainly based on the Freundlich adsorption isotherm, solubility data collected by Keaton and Kardos, and pH-Eh diagram established by Ferguson and Garvis. The computer language used is Turbo PASCAL version 5.5.

The clay soil environment is considered to be in standard state: 25°C 1 atm. Environmental factors of the soil system which are accounted for by the …

Fuzzy Knowledge-Based Approach To Treating Uncertainty In Inventory Control, Dobrilla Petrovic, Edward Sweeney

Articles

Inventory control in complex manufacturing environments encounters various sources of uncertainity and imprecision. This paper presents one fuzzy knowledge-based approach to solving the problem of order quantity determination, in the presence of uncertain demand, lead time and actual inventory level. Uncertain data are represented by fuzzy numbers, and vaguely defined relations between them are modeled by fuzzy if-then rules. The proposed representation and inference mechanism are verified using a large numbers of examples. The results of three representative cases are summarized. Finally a comparison between the developed fuzzy knowledge-based and traditional, probabilistic approaches is discussed.

Selecting Controls For Water Distribution Systems, J. Paul Tullis

Reports

One of the key requirements for reliable operations of a water supply system is a thorough analysis and proper selection of the control valves and pumps. For valves, selection criteria includes capacity, pressure loss, controllability, torque, cavitation and transients. Pump selection requires matching the pump performance to varying system demands. Examples are given for single pump operation and use of pumps in series and parallel. When future demands exceed the original design conditions, or if significant changes are required in the operation of the system, each important control device should be analyzed to see if it can operate safely at …

The Source Hydrology Of Severe Sustained Drought In Th Southwestern U.S., David G. Tarboton

Reports

This paper considers the risk of drought and develops drough scenarios for use in the study of severe sustained drought in the Southwestern United States. The focus is on the Colorado River gbasin and regions to which Colorado River water is exported, especially southern California, which depends on water from the Colorado River as well as the four major rivers in northern California. Drought scenarios are developed using estimates of unimpaired historic streamflow as well as reconstructions of streamflow based on tree ring widths. Drought scenarios in the Colorado River are defined on the basis of annual flow at Lees …

A Spatially Distributed Energy Balance Snowmelt Model, David G. Tarboton, Tanveer G. Chowdhury, Thomas H. Jackson

Reports

This paper describes an energy balance snowmelt model developed for the prediction of rapid snowmelt rates responsible for soil erosion and water input to a distributed water balance model. The model uses a lumped representation of the snowpack with two state variables, namely, water equivalent and energy content relative to a reference state of water in the ice phase at 0 degrees Celcius. This energy content is used to determine snowpack average temperature of liquid fraction. This representation of the snowpack is used to determine snowpack average temperature of liquid fraction. This representation of the snowpack is used in a …

Measurements And Modeling Of Snow Energy Balance And Sublimation From Snow, David G. Tarboton

Reports

Snow melt runoff is an important factor in runoff generation for most Utah rivers and a large contributer to Utah's water supply and periodically flooding. The melting of snow is driven by fluxes of energy into the snow during warm periods. These consist of radiant energy from the sun and atmosphere, sensible and latent heat transfers due to turbulent energy exchanges at the snow surface and a relatively small ground flux from below. The turbulent energy exchanges are also responsible for sublimation from the snow surface, particularly in arid environments, and result in a loss of snow water equivalent available …

The Study Of Resistance And Stability Of Vegetation In Flood Channels, William Rahmeyer, David Werth, Rob Cleere

Reports

Preface: The following report was prepared by the Utah Water Research Laboratory of Utah State University in Logan, Utah. The report contains the data and conclusions of flow tests conducted with different types of shrubs and woody vegetation in the hydraulics flumes of Utah State University. The funding agency for this project was the U.S. Army Engineers Waterwasy Experiment Stations, Vicksburg, MS.; Project Name - Flood Control Channels; Work Unit Title - Stability of Vegetative Cover in Flood Control Channels; Work Unit No - 337A3; Federal Contract No - DACW39-94-K-0009. The study was the result of a proposal submitted in …

The Great Salt Lake: A Barometer Of Low Frequency Climate Variability, Upmanu Lall, Michael Mann

Reports

Low frequency (interannual or longer period) climatic variability is of interest bacause of its sugnificance for the understanding and prediction of protracted climatic anomalies. Closed basin lakes are sensitive to long term climatic fluctuations and integrate out high frequency variability. It is thus natural to examine the records of such lakes to better understand long term climate dynamics. Here we use Singular Spectral Analysis (SSA) and Multi-Taper Spectral Analysis (MTM) to analyze the time series of Great Slat Lake (GSL) monthly volume changes from 1848-1992, and monthly precipitation, temperature and streamflow for nearby stations with 74 or more years of …

Utah Water Research Laboratory Publications Listing 1989-1994, David S. Bowles, Leaunda S. Hemphill

Reports

No abstract provided.

On The Evolution Of Cae Research, Clive L. Dym, Raymond E. Levitt

All HMC Faculty Publications and Research

Less than a decade ago it seemed that a new paradigm of engineering–called computer-aided engineering (CAE) – was emerging. This emergence was driven in part by the success of computer support for the tasks of engineering analysis and in part by a new understanding of how computational ideas largely rooted in artificial intelligence (AI) could perhaps improve the practice of engineering, especially in the area of design synthesis. However, while this “revolution” has failed to take root or flourish as a separate discipline, it has spawned research that is very different from traditional engineering research. To the extent that such …

Modification Of Highway Soil Subgrades, Tommy C. Hopkins, Tony L. Beckham, David Q. Hunsucker

Kentucky Transportation Center Research Report

Major study objectives were to develop highway pavement subgrade stabilization guidelines, examine long-term benefits of chemical stabilizers, such as cement, hydrated lime, and two byproducts from industrial processes, and to establish a subgrade stabilization program in Kentucky. In developing a program, a number of design and construction issues had to be resolved. Factors affecting subgrade behavior are examined. Changes in moisture content and CBR strengths of untreated and chemically treated subgrades at three experimental highway routes were monitored over a 7- year period. CBR strengths of the untreated subgrades decreased dramatically while moisture contents increased. CBR strengths of subgrade sections …

Identification Of Tire Leachate Toxicants And A Risk Assessment Of Water Quality Effects Using Tire Reefs In Canals, S. M. Nelson, G. Mueller, D. C. Hemphill, U.S. Bureau Of Reclamation

Publications (WR)

Cover is an important component of aquatic habitat and fisheries management. Fisheries biologists often try to improve habitats through the addition of natural and artificial material to improve cover diversity and complexity. Habitat-improvement programs range from submerging used Christmas trees to more complex programs using sophisticated artificial habitat modules. Used automobile tires have been employed in the large scale construction of reefs and fish attractors in marine environments and to a lesser extent in freshwater and have been recognized as a durable, inexpensive and long-lasting material which benefits fishery communities.

Recent studies by the U.S. Bureau of Reclamation have quantified …

Landfill Leachate Production And Gas Generation Numerical Model, John Edward Riester Jr.

Civil & Environmental Engineering Theses & Dissertations

Numerous processes occur in landfills which lend themselves to modeling. Many of the processes are mutually interdependent. An unsteady numerical model is developed combining the major processes. The three-dimensional moisture transport equations and boundary conditions are solved using an implicit finite difference scheme. The boundaries are determined through a two-dimensional runoff model for the landfill surface and a one-dimensional leachate liner flow model at the bottom of the landfill. The runoff model accounts for evapotranspiration, runoff, infiltration, and leachate recirculation. Richard's equation is solved for saturated and unsaturated vertical flows and Darcy's Equation is solved for lateral flow between adjacent …

Antecedent Moisture Conditions For Utah Local Storm Probable Maximum Floods, Travis S. Taylor, David S. Bowles

Reports

Introduction: The critical inflow design flood for most dams in Utah is the probable maximum flood (PMF) resulting from the local storm probable maximum precipitation (PMP) event. Commonly, the Soil Conservation Service (SCS) curve number method is used to determine the PMF from the local storm PMP. An important factor in this determination is the assumption of antecedent moisture conditions (AMC) existing immediately prior to the onset of the PMP event. At one northern Utah dam site the use of AMC III increased the PMF peak flowrate by 50 percent over the peak obtained when AMC II was used (Win …

Low Frequency Climate Variability: Understanding The Rise And Fall Of The Great Salt Lake, Michael E. Mann, Upmanu Lall, Barry Saltzman

Reports

Connections between the Great Salt Lake (GSL) volume (V) and large-scale climate variations are developed through an analysis of the time series of the month-to-month differences in V (change in V), local precipitation and streamflow, and gridded U.S. sea level pressure and global temperature data. We isolate decadal and secular mdoes of cliamte variability that are coherent with change in V variations. The decadal variations results from a low-frequency north-south shifting of storm tracks which influence winter precipitation. These variations describe nearly 18% of the interannual variance in change in V, while the secular trend accounts for only ~1.5%. The …

Introducing Uncertainty Of Aquifer Parameters Into An Optimization Model, Robert L. Ward, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

A stochastic analysis is made for a previously described groundwater contaminant management model {Peralta and Ward, 1988). The stochastic model is based on incorporating uncertainty of the aquifer parameters transmissivity and effective porosity into the model. This is accomplished by finding the partial derivative of drawdown with respect to each of these parameters using a Taylor series expansion approximation of the Theis equation. Input that is required for the stochastic version is the mean of the transmissivity and effective porosity, the coefficient of variation of the transmissivity and effective porosity, and a reliability level (0%-100%) . The reliability is a …

Optimizing Irrigation Management For Pollution Control And Sustainable Crop Yield, Ghassan R. Musharrafieh, Richard C. Peralta, Ronald J. Hanks, Lynn M. Dudley

Civil and Environmental Engineering Faculty Publications

Irrigation strategies which maximize crop yield while maintaining target salt concentration in the root zone and/or prevent salt from leaching to the groundwater are computed using a nonlinear, one dimensional, simulation/optimization management model. The included constraint equations maintain a water volume balance and salt transport in the unsaturated zone. Utilized are implicit finite difference forms of the nonlinear, unsteady, unsaturated water flow equation (Richards's equation), and the diffusion-convection solute transport equation. Other constraints include nonlinear functions describing the hydraulic properties of the medium (hydraulic conductivity as a function of matric potential, volumetric water content as a function of matric potential, …

Introduction Of An Information Feedback Loop To Enhance The Urban Transportation Modeling System, Kyle B. Winslow

Theses

The Urban Transportation Modeling System (UTMS) is a methodology used to estimate urban travel demand. This demand is measured as the volume of traffic that flows through a system of streets and highways. Through the use of traffic assignment software, parts of UTMS have become automated. One of the newest automated processes is the extraction of a subarea from a larger model. This extraction process is important to the local planner because it maintains a linkage from the regional model to the local model and it allows the user to extract an already distributed trip table rather than building one …

An Evaluation Of The Strategic Highway Research Project Packing Handbook, Kenneth P. Cox, Charles F. Scholer, Menashi D. Cohen

JTRP Technical Reports

The objective of this research is to evaluate the use of the November 8, 1991 SHRP C-206 report entitled, “Packing Handbook – A Guide to the Optimal Gradation of Concrete Aggregates”. The purpose of the Packing Handbook is to determine the optimal combination of fine and coarse aggregates for concrete from available aggregate sources. Through the use of tables provided in the Packing Handbook, and given sources with known aggregate gradations and void contents, the relative proportion of each aggregate (coarse and fine) is obtained. Concretes made using the Packing Handbook recommendations of aggregate proportioning were compared to concretes used …

Guidelines For Permitting Overloads; Part 1: Effect Of Overloaded Vehicles On The Indiana Highway Network, Sameh Mohamed Zaghloul, Thomas D. White

JTRP Technical Reports

Closed form analysis is commonly used to analyze pavement structures. This type of analysis assumes linear elastic material properties and static loading conditions. In reality, pavement materials are not linear elastic materials. For example, asphalt mixtures are viscoelastic materials and cohesive soils are elastic-plastic materials. Also truck loads are moving loads. The difference between the closed form analysis assumptions and the actual pavement conditions leads to significant differences between measured and predicted pavement response. A study has been conducted at Purdue University to develop a procedure for permitting overloaded trucks in Indiana. This study was funded by the Indiana Department …

Multimedia Application Synthesis Study, Bob G. Mccullouch

JTRP Technical Reports

Multimedia with its ability to involve various human faculties through the use of various media forms, provides a robust environment in which to learn in. Retention improves significantly when media exercises these various human faculties. Studies indicate that students complete training in one-third the time of the traditional instruction method while reaching up to 50 percent higher competency levels. Utilizing this technology can provide improved training tools and learning environments for the Department. Because of the many potential applications, technical and nontechnical, that may exist within the Department for utilizing this technology; a study was performed to answer questions about …

A Conceptual Approach To Water Resources Management For A Catchment In Tanzania, F Mwanuzi

Tanzania Journal of Engineering and Technology (TJET)

In hydrology/Water resources, normally rainfall data are available for longer periods than runoff data. Many attempts have been made to extend these runoff data by using system approach and conceptual models. The conceptual approach to simulate runoff at the outlet ofa catchment is based on the physical processes involved in the transformation of rainfall into runoff (river flow). In this paper a conceptual model, (SEAMOD) has been used. This model has a limited number of parameters to optimize when compared to other models like the sacramental model. Also it requires less input data. The model assumes that the storage is …

Selection Of Design Strengths Of Untreated Soil Subgrades And Subgrades Treated With Cement And Hydrated Lime, David Q. Hunsucker, Tony L. Beckham

Kentucky Transportation Center Research Report

Selection of design strengths of soil subgrades and subgrades treated with cement or hydrated lime is a problem in pavement design analysis and construction because a variety of different types of soils may exist in a highway corridor and a wide range of different strengths may exist after the soils are compacted to form the pavement subgrade. The selected subgrade strength will largely affect the pavement thickness obtained from the design analysis, the future pavement performances, and the overall bearing capacities of the subgrade during construction and the pavement structure after construction. In developing the proposed selection scheme, a newly …

Wildlife Exposure Factors Handbook, Volume I Of Ii, United States Environmental Protection Agency

United States Environmental Protection Agency: Publications

The Exposure Assessment Group of the Office of Health and Environmental Assessment (OHEA) has prepared the Wildlife Exposure Handbook in support of the Office of Solid Waste and Emergency Response and the Office of Water. The Handbook provides information on various factors used to assess exposure to wildlife. The goals of the project are (1) to promote the application of risk assessment methods to wildlife species, (2) to foster a consistent approach to wildlife exposure and risk assessments, and (3) to increase the accessibility of the literature applicable to these assessments.
The bulk of the document summarizes literature values for …

Development Of Computer Software To Aid Environmental Decision Makers In The Education And Training Of Air Force Remedial Project Managers, Roger R. Ouellette, Bruce K. Lyman

Theses and Dissertations

By the end of Fiscal Year 1991, the Air Force had identified 4,354 contaminated sites. Much like the 177 toxic sites at McClellan AFB, bases across the country and throughput the world are filled with chrome, lead, paint solvents and many other toxics that are rendering water supplies unusable and endangering the health of millions of people living in and around these bases. Air Force officials continue to identify contaminated sites with no end in sight. Since the cleanup of these toxic materials involves diverse, complex activities, the Air Force created the duty position of Remedial Project Manager to manage …

Comparison Of The Dynamic Behavior Of Composite Plates And Shells Incorporating Green's Strain Terms With The Von Karman And Donnell Models, Arthur E. Forral

Theses and Dissertations

The dynamic collapse behavior of thin, composite cylindrical shells subjected to transverse point loads is considered. The dynamic behavior of the undamped cylindrical shells of varying radii is analyzed with a finite element formulation that incorporates all nonlinear Green's strain terms in the in-plane directions; transverse strains are linear and vary parabolically through the shell thickness. This formulation is denoted as the simplified large displacement/rotation (SLR) theory. Graphical representations are used extensively to examine dynamic behaviors not noted in similar research that utilized the DSHELL finite element code. Composite plate behavior is also explored. Comparison of the higher-order formulations to …

Pavement Drainage And Pavement Shoulder Joint Evaluation Numerical Analysis Of Infiltration And Drainage In Pavement Systems, Reynaldo David. Espinoza, Philippe L. Bourdeau, Thomas D. White

JTRP Technical Reports

The continuing loss of pavement performance observed in the U.S. transportation infrastructure system raises the issue of the subdrainage design. Experience with the Indiana highways indicates that the lack of adequa the sub-drainage is probably a major cause of pavement distress. In order to provide highway engineers with a methodology to analyze the water migration and drainage into pavement systems a new numerical model has been developed. The numerical scheme is a finite difference formulation of the equations of water flow in unsaturated porous media. The resulting system of equations used is nonlinear and state-of-the-art numerical techniques have been used …

Computer Program For Analysis Of Embankments With Tensile Elements, Mikhail E. Slepak, Tommy C. Hopkins

Kentucky Transportation Center Research Report

A generalized computer program for analyzing stability of earth structures reinforced with geosynthetics (geogrids, geotextiles etc.) was developed in this research study. The newly proposed computer program was built in such a way that a reinforced slope stability problem may be analyzed using a variety of limit equilibrium methods including Hopkins', Morgenstern and Price's, Bishop's methods, Raulin's perturbation method, as well as new perturbation methods proposed by the authors of this study. It was shown in the research study that two versions of the Bishop's method were possible in the case of reinforced analyses: the traditionally used version referred to …

Seismic Code Analysis Of Buildings Without Locating Centers Of Rigidity, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Static force procedures of most building codes require that the lateral earthquake force at each floor level of an asymmetric-plan building be applied eccentrically from the centers of rigidity. To implement such procedures, it seemed necessary in the past to determine the locations of the centers of rigidity, an often confusing and cumbersome process. This paper presents a new approach for code lateral force analysis of asymmetric-plan buildings without locating the centers of rigidity. This procedure combines the results from three static analyses, which can be implemented directly on most commercially available computer programs for analysis of multistory buidings. The …

Water Quality Modeling Of The Tualitin River, Christopher John Berger

Dissertations and Theses

Water quality problems related to excessive algal growth, high nutrient loading, and low flows have been occurring along Oregon's Tualatin River. The Tualatin River is 86 miles long and has a drainage basin of 711 square miles. The drainage basin incorporates forest, agricultural, and urban areas. Located in the Portland metropolitan area, these problems have been acerbated by the effects of urban growth. To help analyze pollution control alternatives, a river model study, funded by the Oregon Department of Environmental Quality (DEQ}, was undertaken. An in-stream model of hydraulics and water quality was developed. The Corps of Engineer's CE-QUAL-W2 model, …