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Articles 13201 - 13230 of 13797

Full-Text Articles in Engineering

Gas Transfer In Diffused Bubble Plumes, Steven C. Wilhelms, Sandra K. Martin Jan 1992

Gas Transfer In Diffused Bubble Plumes, Steven C. Wilhelms, Sandra K. Martin

United States Army: Publications

The gas transfer in aeration systems is broken into two processes: gas transfer at the bubble interface and gas transfer at the water surface. Experiments were conducted to separate these two sources of dissolved gas. Oxygen absorption was measured in a laboratory tank with air being diffused through a porous diffuser and then with nitrogen gas being diffused. The combination of these experiments along with reformulation of the theoretical transfer equation permit separation of the gas transfer at the water surface and in the rising bubble plume. Estimates of the exchange coefficient for the plume and surface are given.

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Hydraulic Structures Versus Zebra Mussels, John J. Ingram, Andrew C. Miller Jan 1992

Hydraulic Structures Versus Zebra Mussels, John J. Ingram, Andrew C. Miller

United States Army: Publications

The United States Army Corps of Engineers (USAE) has begun a four-year research program to develop environmentally sound control strategies for zebra mussel (Dreissena polymorpha) infestations at public facilities. The USAE Waterways Experiment Station has initiated research for these facilities which include water-intake structures, navigation locks, gated dams, outlet works, pumping plants, hydropower plants, drainage structures, dredges and commercial vessels.

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Computation Of Long-Term Three-Dimensional Hydrodynamics Of New York Bight, Keu W. Kim, David J. Mark, Norman W. Scheffner, Lynn M. Bocamazo Jan 1992

Computation Of Long-Term Three-Dimensional Hydrodynamics Of New York Bight, Keu W. Kim, David J. Mark, Norman W. Scheffner, Lynn M. Bocamazo

United States Army: Publications

A time-varying three-dimensional (3D) numerical hydrodynamic model has been applied to the New York Bight to provide flow fields to a 3D water quality model. The spatial computational domain extends from Cape May, New Jersey at its south-west end and Narragansett Bay, Rhode Island, at the north-east end and seaward to the shelf-break. As illustrated below, the numerical model has more than 2500 active horizontal cells and ten vertical layers. Features of the hydrodynamic model include coupling of temperature grids to better represent geometric features, and an algebraic vertical turbulence model based upon the assumption that turbulence production and dissipation …

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Stable Channel And Environmental Design Considerations For An Urban Flood Control Project, Edward F. Sing, Daniel Pridal, Thea Lane Jan 1992

Stable Channel And Environmental Design Considerations For An Urban Flood Control Project, Edward F. Sing, Daniel Pridal, Thea Lane

United States Army: Publications

A case study will be presented of a two phase process of development of the hydraulic design of a flood control project incorporating a creek nestled within an urban greenbelt. The green belt reach consists of the existing, 5 to 15 foot wide tree-lined, low flow channel set within an approximate 100 to 150 foot wide floodway to be created by low berms. Any project features proposed for this reach would need to be environmentally and aesthetically acceptable. The design approach taken in developing the flood control and channel stabilization plan for the greenbelt reach will be presented. This approach …

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Rapid Detection Of Hydrocarbon Contamination In Ground Water And Soil, A. M. Chrestman, G. D. Comes, S. S. Kooper, P. G. Malone Jan 1992

Rapid Detection Of Hydrocarbon Contamination In Ground Water And Soil, A. M. Chrestman, G. D. Comes, S. S. Kooper, P. G. Malone

United States Army: Publications

In situ fluorometry is being developed as a method for rapidly detecting and quantifying hydrocarbon contamination in ground water and soil. The results of a fluorometry survey over a site having known fuel contamination are compared to results from a soil gas survey over the same site. The fluorometry data showed three additional contaminated areas that were not detected by soil gas measurements. Soil analyses confirmed the presence of the contaminated areas.

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Using A Numerical Model To Evaluate Dredging Options, Ronald R. Copeland Jan 1992

Using A Numerical Model To Evaluate Dredging Options, Ronald R. Copeland

United States Army: Publications

A study was conducted to address a shoaling problem in the vicinity of the Cubits Gap distributary on the lower Mississippi River. Upstream from Cubits Gap the river is relatively deep, but the channel depth decreases as it approaches the distributary, where frequent dredging is required. A one-dimensional numerical model was used to evaluate alternative dredging operations and to forecast sediment accumulation. The numerical model was also used to forecast sediment accumulation based on 30-day flow projections. This information can be used to help determine when to initiate dredging fleet mobilization.

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Environmental Engineering Options For Managing Contaminated Sediment, Norman R. Francingues. Jr. Jan 1992

Environmental Engineering Options For Managing Contaminated Sediment, Norman R. Francingues. Jr.

United States Army: Publications

Technologies that have been identified as feasible for remediating contaminated sediment and are peing considered for demonstration in the Great Lakes are presented in this paper. This review is limited to the components and technologies required for removal and management of highly contaminated sediment. Over two hundred technology process options were reviewed for effectiveness, implementability and costs. However, few of these processes have actually been applied to contaminated sediment on a full scale. Most of the technology evaluations have been conducted at the bench scale with limited data available for pilot scale assessment. Therefore, further testing and evaluation of the …

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In-Channel Sediment Basins: An Alternative To Dam-Style Debris Basins, Wendy S. Gist, Scott E. Stonestreet, Ronald R. Copeland Jan 1992

In-Channel Sediment Basins: An Alternative To Dam-Style Debris Basins, Wendy S. Gist, Scott E. Stonestreet, Ronald R. Copeland

United States Army: Publications

In-channel sediment basins were designed, in lieu of a traditional debris basin, to capture large sediment loads at the upstream end of a proposed flood control channel. A numerical model, HEC-6, was used to size the basins.

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Numerical Modeling Of Reservoir Tailrace Hydraulics For Water Quality And Habitat Analysis, Brad R. Hall, John Nestler Jan 1992

Numerical Modeling Of Reservoir Tailrace Hydraulics For Water Quality And Habitat Analysis, Brad R. Hall, John Nestler

United States Army: Publications

The Waterways Experiment Station has developed dynamic numerical hydraulic and water quality simulation models of the Missouri River reaches downstream of Fort Peck, Garrison, and Fort Randall Dams in support of Master Water Control Manual studies. The numerical modeling approach is to compute spatial and temporal variations in stage and discharge in each of these reaches using UNET, a one-dimensional dynamic flow model. Hydraulic and geometric parameters calculated by UNET are then linked with transport algorithms in the CE-QUAL-RIV1 numerical model for computing spatial and temporal variation in water temperature and dissolved oxygen in each of the modeled reaches. Parameters …

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Development Of A Comprehensive Modeling System For Remediation Of Contaminated Groundwater, Jeffrey P. Holland Jan 1992

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 …

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Modeling Dredged Material Disposed In Open Water, B. H. Johnson, D. N. Mccomas, D. C. Mcvan Jan 1992

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 …

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An Acoustic Impedance Method For Subbottom Material Characterization, Richard G. Mcgee, Robert F. Ballard, Jr. Jan 1992

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.

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Overtopping Protection Alternatives For Dams, Noel R. Oswalt Jan 1992

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, …

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A Numerical Simulation Approach To Estimating Disposal Site Stability, Norman W. Sheffner Jan 1992

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.

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Reduced Recharge Capacity Of A Pump And Treat System, Cynthia L. Teeter, Douglas Gunnison, Norman R. Francingues, Mark E. Zappi Jan 1992

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 …

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Design Of Pneumatic Diffuser System, Steven C. Wilhelms, Charles W. Downer, Richard E. Price Jan 1992

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.

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Treatment Of Contaminated Groundwater Using Chemical Oxidation, Mark E. Zappi, Beth C. Fleming, M. John Cullinane Jan 1992

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.

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Verification Techniques Used In Modeling Charleston Harbor, South Carolina, Samuel B. Heltzel Jan 1992

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 …

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Properties Of Solidified/Stabilized Chromium Contaminated Soil, Beth C. Fleming, M. John Cullinane, Jr Jan 1992

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 …

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A Methodology For Customer Requirements Generation In Communication Systems Planning, Negaa Albegami, Yildirim Omurtag Jan 1992

A Methodology For Customer Requirements Generation In Communication Systems Planning, Negaa Albegami, Yildirim Omurtag

Engineering Management and Systems Engineering Faculty Research & Creative Works

In electronic communication systems it is nearly impossible to keep up with changing technology. This problem is further aggregated in the developing countries where the contractor (probably a western company) is expected to develop the system from the ground up. A basic problem which confronts this approach is either: 1) The customer will start adding or rejecting some of the capabilities, or 2) The local operation will never use some of the capabilities. Both of these outcomes are costly in terms of time and resources available to a developing country. This paper describes a new methodology for requirements generation to …

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Computer Networking For Operation Management And Optimization In Power Utility Industry, Ali K. Kamrani, Kamran K. Kamrani Jan 1992

Computer Networking For Operation Management And Optimization In Power Utility Industry, Ali K. Kamrani, Kamran K. Kamrani

Engineering Management and Systems Engineering Faculty Research & Creative Works

The connectivity, flexibility, and real time control capability of computer systems have led electric utility companies to consider the use of computers and telecommunication networks. The application of such an environment includes data acquisition, supervisory control, operation optimization, and data management. This paper presents the layout of a computer system network for an electric power utility.

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Moving Object Recognition And Guidance Of Robots Using Neural Networks, Abhijit Neogy, S. N. Balakrishnan, Cihan H. Dagli Jan 1992

Moving Object Recognition And Guidance Of Robots Using Neural Networks, Abhijit Neogy, S. N. Balakrishnan, Cihan H. Dagli

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The design of a robust guidance system for a robot is discussed. The two major tasks for this guidance system are the online recognition of a moving object invariant to rotation and translation, and tracking the moving object using a neural-network-driven vision system. This system included computer software ported to the IBM PC and interfaced with an IBM 7535 robot. The operation of this guidance system involved recognition of a moving object and the ability to track it till the robot and effector was in close proximity of the object. It was found that the robot was able to track …

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Flow Impingement Velocities, Snake River, Wyoming, Stephen T. Maynord Jan 1992

Flow Impingement Velocities, Snake River, Wyoming, Stephen T. Maynord

United States Army: Publications

Flow impingement, which occurs when approach channels direct flow into a bank line at large acute angles, results in flow concentration along bank lines, which creates large forces on bank material or bank protection. As part of studies conducted to determine the required riprap size for impinged flow, velocities were measured on the Snake River near Jackson, Wyoming. High velocities and steep water-surface slopes were observed at each impingement site.

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Revised Hydraulic Design Of The Los Angeles County Flood Control System, Michael E. Mulvihill, Scott E. Stonestreet Jan 1992

Revised Hydraulic Design Of The Los Angeles County Flood Control System, Michael E. Mulvihill, Scott E. Stonestreet

United States Army: Publications

The US Army Engineer District, Los Angeles, recently completed a study regarding the adequacy of an existing flood control system in Los Angeles County. Results of this study indicate that the level of protection afforded by the system is as low as 25-year in heavily urbanized areas. The Corps of Engineers plans to increase the capacity in two mainstem channels, raising the level of protection to greater than 1OO-year, by constructing parapet walls on top of existing levees and modifying constrictive bridges. A physical model study will be conducted to aid in analysis of complex design problems and will provide …

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Levee/Floodwall Freeboard Design For An Urban Flood Control Project, Daniel B. Pridal, Edward F. Sing Jan 1992

Levee/Floodwall Freeboard Design For An Urban Flood Control Project, Daniel B. Pridal, Edward F. Sing

United States Army: Publications

A methodology for the design of levee/floodwall freeboard using evolving guidelines based on the concept of superiority is presented. A case study illustrating the application of the freeboard design guidelines to the Truckee Meadows Project is shown. The Truckee Meadows Project provides a 100 year level of flood protection through the Reno-Sparks, Nevada metropolitan area along an approximate ten mile reach of the Truckee River. Major features of the project include levees, floodwalls, channel modifications, bridge replacement or reconstruction, a detention basin, and drainage improvements. The project is presently in the Preconstruction, Engineering and Design (PED) Phase within the Sacramento …

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Removal Of Extremely Low Levels Of Munitions In A Drinking Water Supply, R. Mark Bricka, Wayne Sharp Jan 1992

Removal Of Extremely Low Levels Of Munitions In A Drinking Water Supply, R. Mark Bricka, Wayne Sharp

United States Army: Publications

Past military operations have resulted in the contamination of soils by chemical munitions such as RDX, HMX and TNT (contaminant description, page 2) . The migration of water through the soils can transport the contaminants into groundwater and contaminate drinking water sources . Many military munitions are known or suspected to be carcinogenic and, therefore, must be removed from drinking water .

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Analyses Of Special Hazards And Flooding Problems In Tropical Island Environments, Robert C. Macarthur, Douglas L. Hamilton, Michael D. Harvey, Hudson W. Kekaula Jan 1992

Analyses Of Special Hazards And Flooding Problems In Tropical Island Environments, Robert C. Macarthur, Douglas L. Hamilton, Michael D. Harvey, Hudson W. Kekaula

United States Army: Publications

Data and results summarized in this paper show that development of urban projects and design of flood control works in tropical island catchments must consider clear water flooding as well as special hazards such as landslides, flow bulking, high sediment concentrations, mud and debris flows and flow avulsions. The needs for and methods to estimate peak flows, event volumes and the potential extent and depths of flooding during severe storm events in urbanizing tropical environments are described.

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Contaminant Groundwater Interception - Rma, S. Paul Miller, William L. Murphy Jan 1992

Contaminant Groundwater Interception - Rma, S. Paul Miller, William L. Murphy

United States Army: Publications

Resolution of groundwater contamination is the major environmental concern at most contamination sites. At some sites immediate control is required to prevent further damage. This paper describes a pioneer groundwater interception and treatment system developed and evaluated at a major Army installation.

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The Management Of Change: A Case Study, Stephen A. Raper, Richard Neal Callahan Jan 1992

The Management Of Change: A Case Study, Stephen A. Raper, Richard Neal Callahan

Engineering Management and Systems Engineering Faculty Research & Creative Works

A literature review was conducted to identify some of the requirements for competitiveness and change that are being promoted by leaders in the manufacturing field. A survey was developed based on the literature review and was subsequently administered, via the case study method, at a midwestern US agricultural chemicals firm to determine the company's degree of compliance with the literature''s recommendations. To a large degree, the company complied with the requirements.

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Application Of Total Quality Management To Research And Development: An Historical Perspective, Scott A. Dellana, Henry Allen Wiebe Jan 1992

Application Of Total Quality Management To Research And Development: An Historical Perspective, Scott A. Dellana, Henry Allen Wiebe

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper discusses the historical applications of Total Quality Management (TQM) to Research and Development (R&D). Research aimed at establishing an effective model for the application of TQM philosophies and tools to the R&D environment must start from this historical perspective. The emphasis of this paper is on the relationship of quality tools and techniques to the application of TQM in R&D, providing the foundation for further model development. The scope and definition of R&D is presented and is followed by an overview of the TQM philosophy and its associated tools and techniques. Special attention is given to defining performance …

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