Engineering Commons^™

Development Of A Comprehensive Modeling System For Remediation Of Contaminated Groundwater, Jeffrey P. Holland

United States Army: Publications

The U.S. Army Engineer Waterways Experiment Station (WES) has proposed development of a Groundwater Modeling System (GMS) for simulating groundwater flow, the transport/fate of subsurface contaminants, and the efficacy of remedial actions. The GMS is proposed to support the needs of the U.S. Army in three main areas: site characterization, contamination assessment, and evaluation of remediation alternatives. To do this, the GMS will include numerical algorithms for simulating the hydrogeologic and biogeochemical processes that must be considered when developing remediation programs for Army and other sites. An essential feature of the GMS will be user interfaces which augment model application …

Modeling Dredged Material Disposed In Open Water, B. H. Johnson, D. N. Mccomas, D. C. Mcvan

United States Army: Publications

Physical model disposal tests at a 1:50 scale have been conducted to provide guidance on numerical model developments and to provide data sets for numerical model verification. These tests have been conducted with a model split-hull barge and a multibin hopper vessel. Both stationary and moving disposals have been monitored. Results imply that the bulk behavior of the disposal material in both the descent and bottom surge phases can be approximately scaled to the prototype. Visual observations have resulted in modifications to an existing numerical model such that the disposal is represented by a series of downward convecting clouds from …

An Acoustic Impedance Method For Subbottom Material Characterization, Richard G. Mcgee, Robert F. Ballard, Jr.

United States Army: Publications

This paper discusses modified seismic reflection technique tailored to the characterization of bottom and subbottom materials. The application of acoustic impedance principles has resulted in the development of a method for rapidly determining the type and density of subbottom materials scheduled for dredging. Acoustic theory is discussed only in sufficient detail to enable the reader to understand basic concepts.

Overtopping Protection Alternatives For Dams, Noel R. Oswalt

United States Army: Publications

A reevaluation of design floods for dam safety within the united states showed that the need to modify dams to accommodate larger floods has greatly increased in recent years. The occurrence of larger design floods would result in overtopping of the dams at many existing reservoirs due to insufficient storage or release capacity. When the addition of storage or release capacity becomes impractical or too costly, dam owners must sometimes resort to providing overtopping protection.
An ASCE Hydraulics Division Task committee on Alternatives for Overtopping Protection for Dams was established in 1991 to inventory and evaluate modification alternatives for new, …

A Numerical Simulation Approach To Estimating Disposal Site Stability, Norman W. Sheffner

United States Army: Publications

A systematic methodology is described for estimating the long-term response of a dredged material site to local environmental forcings. The methodology is based on the development of user-accessible data bases of wave and current time series and the subsequent application of these boundary conditions to coupled hydrodynamic, sediment transport, and bathymetry change models. The approach was developed to provide an estimate of long-term material fate for use in determining whether an existing or proposed disposal site will be dispersive or nondispersive over periods of time on the order of months to years.

Reduced Recharge Capacity Of A Pump And Treat System, Cynthia L. Teeter, Douglas Gunnison, Norman R. Francingues, Mark E. Zappi

United States Army: Publications

The North Boundary treatment system at Rocky Mountain Arsenal (RMA), Commerce City, Colorado, involves pumping of contaminated groundwater from an unconfined aquifer from one side of a soil-bentonite (SB) slurry wall to three pulsed-bed activated carbon adsorbers and prefilter and postfilter systems. The treated water is injected into the unconfined aquifer on the other side of the slurry wall via 38 recharge wells and 15 recharge trenches, collectively referred to as the recharge system. Recharge capacity of the recharge system has declined over time, limiting the operating capacity of the system. Two probable causes for reduction of the recharge systems …

Design Of Pneumatic Diffuser System, Steven C. Wilhelms, Charles W. Downer, Richard E. Price

United States Army: Publications

During non-generation periods, leakage through the wicket gates of a hydroturbine often results in very poor quality water (low or zero dissolved oxygen) in the tailrace of the hydropower facility. Generally, the leakage rate is relatively small, usually about 5-10 cfs per turbine. A bottom-mounted diffuser system was designed based on laboratory-measured and manufacturer-supplied specifications about the gas transfer characteristics of the bubble plume generated by an 11- inch flexible head diffuser. The design criteria and the overall effectiveness of the system were evaluated in field tests at Lake Eufaula, Oklahoma. The analysis of field data is reported herein.

Treatment Of Contaminated Groundwater Using Chemical Oxidation, Mark E. Zappi, Beth C. Fleming, M. John Cullinane

United States Army: Publications

Chemical oxidation was evaluated for treatment of a groundwater contaminated with trichloroethylene, acetone, and other organic compounds as measured by the biochemical oxygen demand (BOD) test. Results indicated that maximum contaminant removal was obtained using a combination of hydrogen peroxide, high intensity ultraviolet light, and the addition of tungsten trioxide under acidic conditions.

Npdes Permitting For Storm Water Discharges Associated With Industrial Activity, Paul Makowski, John G. Garland Iii

United States Air Force: Publications

Recent changes to the National Pollutant Discharge Elimination System (NPDES) program require that storm water discharges associated with industrial activity and from municipal separate storm sewer systems serving a population of 100,000 or more be regulated under the NPDES program. These changes greatly expanded the number of industrial facilities subject to the NPDES program. An industrial facility that is subject to the regulation must apply for a storm water permit based on application requirements that were recently established. The NPDES permit application process for storm water discharges associated with industrial activity is discussed.

Structural And Non-Structural Alternatives For Accommodating Larger Floods At Dams, Louis E. Buck

United States Department of Energy: Publications

This paper provides an overview of structural and non-structural alternatives for accommodating larger floods at dams. The first two alternatives discussed, raising the height of the project and/or lowering the reservoir pool, can be used to prevent overtopping by increasing the available floodwater detention storage in the reservoir. Data gathered by an ASCE task committee survey on modifications that include increased storage by raising project height are summarized and discussed. The third alternative discussed, early warning systems, can provide a low cost alternative to structural modifications. Case studies for the warning systems at the Santee Cooper North Dam and the …

Integrated Assessment Of Temperature Change Impacts On The Tva Reservoir And Power Supply Systems, B. A. Miller, V. Alavian, M. D. Bender, D. J. Benton, P. Ostrowski Jr., J. A. Parsly, M. C. Shiao

United States Department of Energy: Publications

Power systems often depend upon reservoir operations to generate hydropower, as well as to support thermal (nuclear and fossil) power generation. Thermal power plants frequently utilize reservoirs/rivers to provide condenser cooling water, dissipate thermal waste discharges, and/or supply safety intake water for emergency cooling systems at nuclear plants. Support of power production, however, must usually be balanced against other reservoir multiple uses such as flood control, navigation, recreation, water supplies, and environmental management.

Contaminated Sediment Transport During Floodsl, Thomas A. Fontaine

United States Department of Energy: Publications

Over the past 48 years, operations and waste disposal activities at Oak Ridge National Laboratory have resulted in the contamination of parts of the White Oak Creek catchment. The contaminants presenting the highest risk to human health and the environment are particle reactive and are associated with the soils and sediments in the White Oak Creek drainage system. The erosion of these sediments during floods can result in the transport of contaminants both within the catchment and off-site into the Clinch River. A data collection program and a modeling investigation are being used to evaluate the probability of contaminated sediment …

Dynamic Plug Flow Reactor Network Model For Contaminant Transport In Water Distribution Systems, James Uber, Ken Hickey, Mao Fang, Lew Rossman

United States Environmental Protection Agency: Publications

We present a network water quality model that idealizes the distribution system as a network of ideal flow reactors, namely plug flow reactors. The plug flow reactors are linked together through an assumption of complete mixing at the network nodes. The resulting system of coupled 2-D (space - time) partial differential equations are discretized spatially using a finite difference scheme, and solved by numerical integration. The model will be evaluated with regard to its prediction capabilities, relative to previous modeling efforts.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 8, Number 1, January 1992, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Verification Techniques Used In Modeling Charleston Harbor, South Carolina, Samuel B. Heltzel

United States Army: Publications

Verification to field data provides a means to assess a model's ability to reproduce behavior of the natural system being modeled. Often neither time nor funds are available to collect extensive sets of field data, and alternate techniques are required. This study used the results of a laterally averaged model to provide limited verification for a two-dimensional depthaveraged hydrodynamic and sediment model.

This numerical model investigation used the US Army Corps of Engineers TABS-MD numerical modeling system for open channel flow and sedimentation. Boundary conditions and a verification data set were obtained from the laterally averaged numerical model FIne-Grained Bed …

Properties Of Solidified/Stabilized Chromium Contaminated Soil, Beth C. Fleming, M. John Cullinane, Jr

United States Army: Publications

Solidification/stabilization (S/S) of chromium contaminated soils is influenced by the oxidation state of the chromium. The sum of the hexavalent chromium and trivalent chromium represent the total chromium concentration which is used to determine whether the soil meets the criteria for chromium in the Toxicity Characteristic Leaching Procedure (TCLP) or whether the levels of chromium in applicable extractions are below the drinking water standard. Hexavalent chromium is the more mobile form of chromium and also the more toxic.
Seven vendors and the U.S. Army Engineer Waterways Experiment Station (WES) evaluated SIS treatment of chromium contaminated soils collected from a Superfund …

A Demonstration Of Machine Control Using The Slc-150 Microprocessor Programmable Controller, Mike Courts, Richard Schmitz

Graduate Student Work

This project will use an Allen-Bradley SLC-150 microprocessor programmable controller to demonstrate an actual application being used in industry. The SLC-150 will be used to sequentially control a Pelco pan and tilt drive unit. This unit is mounted with a video camera that is used for security monitoring. The SLC-150 will also control the cameras zooming features.

Prior to microprocessors the electrical control of machines used input devices such as push buttons and limit switches connected to magnetically hard wired relay logic. Hard wiring meant that electrical wires were connected between all relay coils and contacts, making up what is …

Bulletin No 4216 - Broadscale Boom Spraying, Roger Doyle, Gary Dorr, Des Gilbey, John Peirce

Bulletins 4000 -

For spraying to be effective it must do the job required at a minimum cost, with no unwanted side effects. It is impo1tant to use the right chemical at the right rate, at the right tin1e and in the best conditions.

It is just as important that both the sprayer and the way it is used allows you to meet this objective. This Bulletin will help you select the right boom sprayer, maintain it for efficient operation and use it efficiently and safely.

Electromagnetic Focusing Properties Of Chirped Metallic Gratings, Jeffrey C. Schmidt

Retrospective Theses and Dissertations

The focusing properties of chirped diffraction gratings have long been studied and often used in applications at optical frequencies. Chirped metallic gratings of this type have also been studied theoretically at microwave frequencies, but no attempt has been made to experimentally examine or utilize the focusing properties of these structures at microwave frequencies. This thesis presents an experimental analysis of the focusing properties of chirped metallic gratings. These gratings are designed to focus electromagnetic energy at a predetermined position by varying strip width and spacing as a function of position. The diffraction gratings are characterized, and experimentally measured results are …

Effect Of Operating Conditions On Gearbox Noise, Fred B. Oswald, James J. Zakrajsek, Dennis P. Townsend, William Atherton, Hsiang Hsi Lin

Mechanical Engineering Faculty Publications

Low-contact-ratio spur gears were tested in the NASA gear noise rig to study the noise radiated from the top of the gearbox. The measured sound power from the gearbox top was obtained from a near-field acoustic intensity scan taken at 63 nodes just above the surface. The sound power was measured at a matrix of 45 operating speeds and torque levels. Results are presented in the form of a spectral speed map and as plots of sound power versus torque (at constant speed) and as sound power versus speed (at constant torque) Because of the presence of vibration modes, operating …

Comparison Of Analysis And Experiment For Gearbox Noise, Fred B. Oswald, A. F. Seybert, T. W. Wu, William J. Atherton

Mechanical Engineering Faculty Publications

Low-contact-ratio spur gears were tested in the NASA gearnoise rig to study the noise radiated from the top of the gearbox. Experimental results were compared with a NASA acoustics code to validate the code for predicting transmission noise. The analytical code is based on the boundary element method (BEM) which models the gearbox top as a plate in an infinite baffle. Narrow-band vibration spectra measured at 63 nodes on the gearbox top were used to produce input data for the BEM model. The BEM code predicted the total sound power based on this measured vibration. The measured sound power was …

Stubble : Friend And Foe, Department Of Agriculture And Food, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

Several articles in this issue of the Journal of Agriculture discuss some of the important issues of stubble management. The articles are condensed from some of the papers presented at a stubble workshop at Geraldton in 1991.

Stubble Handling Machinery, Greg Haydon

Journal of the Department of Agriculture, Western Australia, Series 4

Farming in Western Australia, and in Australia, has undergone a revolution over the past 15 to 20 years. Two significant changes have been the cessation of ploughing to kill weeds, that is, the change from discs to tines, and the reduction in tillage through the use of agricultural chemicals. These have been important changes that have had conservation benefits. However, to handle stubble to best effect, further changes in machinery, newer machinery and combinations of machines will be needed. In this article, the author discusses current and possible future practces.

Stubble Handling Begins At Harvest, Ed Blanchard

Journal of the Department of Agriculture, Western Australia, Series 4

Long stubble left in the paddock after harvest causes major difficulties at seeding time. To demonstrate the benefits of having short stubble at seeding, the Trayning Land Conservation District Committee created four stubble treatments at harvest in 1988 and sowed into these stubble treatments in 1989.

Effect Of Surface Treatments On Dentin Bonding Shear Strength, James L. Drummond, D. Racean, J. Van Scoyoc, A. Steinberg

Cells and Materials

The purpose of this study was to determine whether four different treatments on wet or dry teeth, on the buccal and occlusal surfaces, affected the shear bond strength. The surface treatments consisted of a dentin conditioner (pH = 4.0), 10% phosphoric acid (pH = 1.6), 2.5 % nitric acid (pH = 1.0), and 2.5 % citric acid (pH = 1.0). One dentin bonding system and one dental composite was used for all of the specimens. The teeth were mounted in acrylic, ground and etched with the appropriate agent for 15 seconds. The dentin adhesive and composite were applied and the …

Review: Biomaterials For Abdominal Wall Reconstruction, Roger K. J. Simmermacher, Robert P. Bleichrodt, Jeff M. Schakenraad

Cells and Materials

The reconstruction of large abdominal wall defects still is a major surgical problem. Many different techniques have been developed for this purpose, most of which appeared to be unsatisfactory. The lack of sufficient tissue requires the insertion of prosthetic material. Non-absorbable prostheses used to reconstruct abdominal wall defects showed the best results . Polypropylene mesh (PPM) and expanded polytetrafluoroethylene (ePTFE) soft-tissue patch are the most frequently used materials for this purpose . However, PPM induces extensive visceral adhesions and erosion of the skin, whereas ePTFE is insufficiently anchored to the adjacent tissue and therefore both materials are not ideal. As …

Optimizing Ground Water Planning And Management, Richard C. Peralta, L. S. Willardson

Civil and Environmental Engineering Faculty Publications

Simulation/optimization (S/0) models can be used to speed the process of computing long term groundwater pumping strategies. These combined models can also greatly ease the planning tasks of water management agencies. They make the process of computing optimal perennial yield groundwater management strategies fairly straightforward. S/0 models dramatically improve conjunctive water management and can help minimize the cost of groundwater contaminant clean-up. The differences between S/0 models and the simulation (S) models currently used by over 98 % of practitioners are illustrated with recent applications of S/0 models in regional planning.

Optimal Groundwater Quantity/Quality Planning For Salt Lake Valley, Ali Gharbi, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Generally, the embedding technique for optimizing groundwater management has been limited to small scale or steady-state groundwater flow management cases. The embedding approach causes sparse, highly structured constraint matrices which have been sometimes difficult to solve. Embedding applications have been limited by lack of: optimization algorithms able to easily address such matrices for large scale problems, and efficient methods for addressing common nonlinearities and converging to a solution. Computer software, USUEM, addresses these issues by: creation of alternative linear, nonlinear, combined and partitioned formulations of the same problem, implemention of an efficient cycling procedure, and good selection of optimization algorithm …

Bioengineering For Water Cleanup: State-Of-The-Art Assessment, Judith L. Sims, Ronald C. Sims, Jon S. Ginn

Reports

No abstract provided.

Evaluation Of Mechanisms Of Alteration And Humification Of Pahs For Water Quality Management, Ronald C. Sims, Carolyn K. Abbott

Reports

Introduction: Creosote-pentachlorophenol (PCP) is a mixture commonly used as a wood preservative in the U.S. (1). A 1988 survey (2) indicated that 1,397 wood preserving waste contaminated sites exist in the United States consisting of 555 active wood treatment plants and 842 inactive plants. Stinson (3) indentifed 58 wood preserving sites on the National Priorities List, of which 51 have PCP and/or creosote or polycyclic aromatic hydrocarbon (PAH) contamination. Principal classes of organic constituents present in creosote waste are PAHs (~85% by weight) and phenolics. PAHs with less than three fused benzene rings comprise 69% (i.e., naphthalene, anthracene and phenanthrene); …