Engineering Commons^™

The Components And Benefits Of An Advanced Surface Arterial Traffic Management System, Ted M. Andrews, Kumares C. Sinha

JTRP Technical Reports

Traffic congestion has become an increasing problem on major surface arterial roadways. Demand for accessibility to adjacent land uses yields increased vehicular turning movement activity at driveways and intersections. As turning and cross-road traffic volumes increase, the need for traffic signalization will eventually be warranted. When numerous, independently operating traffic signals are present on a given arterial roadway, adverse effects can result. First, continous movement along the arterials at a desirable speed may not be assured. Second, vehicular delay will increase because of the slower operating speeds and increased number of stops. Third, safety can be threatened as poor traffic …

South Dakota Project P 0019(20)0 Pcems 238h Nebraska Project Stpd-57-4(108) Missouri River Bridge Near Vermillion Clay County, South Dakota Cedar And Dixon Counties, Nebraska, James Nelson, Arthur Yonkey, Lubin Quinones

United States Army Corps of Engineers, Omaha District

The South Dakota Department of Transportation (SDDOT) and the Nebraska Department of Roads (NDOR) propose to build a bridge over the Missouri River in the vicinity of Vermillion, South Dakota and Newcastle, Nebraska. (See Figure 1 for a computer image of this proposed bridge.) SO Highway 19, SO Highway 50 and Interstate 29 would connect with Nebraska Highway 12. The Nebraska approach roadway would be designed to provide two 3.6 meter (11.8-foot) driving lanes with 1.8 meter (6-foot) shoulders. The South Dakota inter-connecting roadway will be designed to provide two 3.6 meter (11.8-foot) driving lanes with two 3 meter (10-foot) …

Final Environmental Assessment For Endangered Species Habitat Improvement/Creation In The Missouri River Between The Niobrara River And Ponca, Nebraska

United States Army Corps of Engineers, Omaha District

An environmental assessment has been prepared for new habitat development in upper Lewis and Clark Lake and the Missouri River below Gavins Point Dam. The actions described are in response to the November 1990, U.S. Fish and Wildlife Service Biological Opinion on the operation of the Missouri River Main Stem System, and will provide safer nesting habitat for the interior least tern (endangered species) and the piping plover (threatened species).

Vegetation on the river islands will be removed and maintained in the "sparsely vegetated" state needed for nesting habitat for the terns and plovers. After vegetation removal, the islands will …

The Status Of Nebraska Fishes In The Missouri River. 6. Sauger (Percidae: Stizostedion Canadense), Larry W. Hease

United States Army Corps of Engineers, Omaha District

Saugers were once common representatives of the Missouri River fish assemblage. Prior to channelization and impoundment, they comprised from 10 to 65% of the main channel big-river fish group. They utilized the slower side channels and backwaters seasonally for feeding, resting, and maturing, but the main channel was important for breeding habitat, Since the onset of channelization and impoundment, saugers have been reduced by as much as 98% in some areas, and the trend toward extirpation continues unabated today. Recovery of native sauger stocks will require a complete cessation of harvest, recovery of the natural hydrograph, recovery of sediment transport, …

Monte Carlo Calculation Of Effective Diffusivities In Two- And Three-Dimensional Heterogeneous Materials Of Variable Structure, Mark R. Riley, Fernando J. Muzzio, Helen M. Buettner, Sebastian C. Reyes

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A Monte Carlo technique that simulates tracer diffusion in multiphase materials of arbitrary complexity has been developed. Effective diffusivities are calculated for structures consisting of either overlapping or nonoverlapping inclusions with diffusivity D_c, distributed in a continuous phase with diffusivity D₀>D_c. Two-dimensional simulations for various values of D₀/D_c generate normalized diffusivities that correspond closely to their three-dimensional counterparts; they nearly collapse to a common curve when a simple scaling relation is applied.

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 …

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 …

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 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 …

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 …

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 …

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.

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, …

Preventing Pesticide Contamination Of Groundwater While Maximizing Irrigated Crop Yield, Richard C. Peralta, M. A. Hegazy, G. Musharrafieh

Civil and Environmental Engineering Faculty Publications

A simulation/optimization model is developed for maximizing irrigated crop yield while avoiding unacceptable pesticide leaching. The optimization model is designed to help managers prevent non-point source contamination of shallow groundwater aquifers. It computes optimal irrigation amounts for given soil, crop, chemical, and weather data and irrigation frequencies. It directly computes the minimum irrigated crop yield reduction needed to prevent groundwater contamination. Constraint equations used in the model maintain a layered soil moisture volume balance; describe percolation, downward unsaturated zone solute transport and pesticide degradation; and limit the amount of pesticide reaching groundwater. Constraints are linear, piecewise linear, nonlinear, and exponential. …

Bs News

Building Services Engineering

No abstract provided.

Bs News

Building Services Engineering

No abstract provided.

Determination Of Aashto Layer Coefficients For Granular Materials By Use Of Resilient Modulus, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The layer coefficients a₂ or a₃ for an unbound granular base or subbase material are found from a relationship with resilient modulus, E_b. The resilient modulus for a given material can be found by test using the "theta model" or by use of an estimation regression equation. E_b is a function of several factors, as discussed below.

Estimation Of Resilient Modulus Of Fine-Grained Subgrade Soils, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Edge Strength Of Window Glass By Mechanical Test, Chris P. Pantelides, Gregory P. Sallee, Joseph E. Minor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A mechanical test is described that can be used to measure the edge strength of annealed and heat-strengthened glass. The mechanical test apparatus stresses only one of the two edge-lines on the edge of a glass specimen. The testing concept employs the theory of unsymmetrical bending. The test device loads glass specimens in a manner that places tensile stresses on the tested edge-line while keeping the other edge-lines at zero stress or in compression. In annealed glass tests, the scored edge-line was found to be 20% weaker than the edge-line opposite the scored edge-line. Comparisons between the edge strengths of …

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 …

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 …

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 …

Critical Evaluation Of The Effects Of Changes Made To Roughing Filters Of Mpira-Balaka Plant On Its Treatment And Operational Performance, C Zulu

Tanzania Journal of Engineering and Technology (TJET)

Mpira Balaka, a full scale rural water supply project was constructed in Ntcheu, Malawi, in 1988 utilising Slow Sand Filtration (SSF) as the main treatment process and roughing filtration as the pretreatment method,following the promo- tion of this technology by various international institutions. During the rainy seasons, the treatment plant for Mpira Balaka failed to cope with the high raw water turbidity, resulting into very short filter run times and hence also to unavoidable distribution Of very turbid water to the rural communi- ties as a result Of by-passing the filters. Of the fifty or so existing rural projects in …

Modeling Technique For Optimal Recovery Of Immiscible Light Hydrocarbons As Free Product From Contaminated Aquifer, Grant S. Cooper Jr., Richard C. Peralta, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

Contamination sites associated with light non-aqueous phase liquids {LNAPL) are numerous and represent difficult cleanup problems. Remediation methods for cleanup of LNAPL fluids in subsurface systems are continuously evolving with the development of various technologies for pump.-and~treat, soil venting, and in-situ bioremediation. Evaluating the effectiveness of remediation techniques as well as attempting to improve their efficiency has been a focus of many researchers, These efforts have included the development of computer simulation models to predict and analyze the fluid movement, entrapment, and mobilization of three~phase systems in porous media. The capability of computer models that not only simulate but optimize …

Wildlife Exposure Factors Handbook, Appendix: Literature Review Database, Volume Ii Of Ii, United States Environmental Protection Agency

United States Environmental Protection Agency: Publications

This Appendix is intended to accompany the Wildlife Exposure Factors Handbook (hereafter referred to as the Handbook) and should be used only by individuals familiar with the Handbook. The species-specific values for the exposure factors presented in Chapter 2 of the Handbook of are a subset of the data included in the tables of this Appendix. Most values identified in the literature reviewed for the Handbook are included in this Appendix. For some exposure factors for some species, large quantities of data are available. For these factors and species, we tried to select data that represented a range of values …

Bulletin 4265 - Termites, Peter Davis

Bulletins 4000 -

Termites are small, soft-bodied, social insects that feed on wood, grass, dead leaves, bark, humus, fungi or the dung of herbivore. They are commonly known as white ants, but are not related to true ants.

There are over 2300 species of termite of which about350 occur in Australia, and of these about 12 damage sound timber.

Development Of Guidelines And Performance For Asphalt Concrete Containing Recycled Rubber, Kamyar C. Mahboub, Donn E. Hancher

Kentucky Transportation Center Research Report

The primary objective of this study was to investigate the feasibility of implementation of the crumb rubber technology in Kentucky. The impetus for this study was provided by the lntermodal Surface Transportation Efficiency Act of 1991 (ISTEA).

This study included an overview of existing literature on the subject from an implementation point of view for Kentucky's conditions. Upon completion of this phase of the study, guidelines were developed by the KTC research team and were submitted to the Transportation Cabinet for field implementation of the crumb rubber modifier (CAM) technology in Kentucky. From the ease of implementation point of view, …