The Effectiveness of Telecommuting as a Transportation Control Measure
This paper examines the potential of telecommuting as a strategy for managing travel demand. In particular, the paper focuses on the travel and air quality implications of telecommuting....
Modified QUAL2E Modeling of a Stream Acutely Impacted by Photosynthesis and Respiration
The QUAL2E model was modified to account for time variable headwater conditions and the photosynthesis and respiration of attached aquatic plants. With these modifications, a stream that...
Hydropower, Water Quality and Waste Discharge
Development of multiple hydroelectric projects on large river systems can result in potential reductions in dissolved oxygen (DO) concentrations. Municipalities along the Ohio River basin...
Waterfall Aeration Works
When they sought an alternative for instream aeration in Chicago's Calumet Waterway System, engineers at the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC)...
The PowerBarge
Following a brief description of the prefabricated floating PowerBarge concept, the range of application and expected cost and time savings is presented. Environmental benefits are described...
Barometric Pumping of Contaminated Gases Through Fractured Permeable Media
Contaminated gases may be transported vertically through a fractured permeable medium by the breathing process which is associated with cyclical changes in the barometric pressure. A review...
Automated Sensitivity Analysis for FORTRAN Models
For complex computer models used in engineering design and assessment, a cost-efficient procedure for identifying the parameters that are important to a given model prediction is a necessity....
Evolution (1980-1990) of Ammonia and Dissolved Oxygen in Guanabara Bay, RJ, Brazil
The UFRJ is located on an island of Guanabara Bay and the Institute of Biology has been developing systematic studies on the bay. A synthesis of these studies and their different methodologies...
Environmental Impacts of Drought in the Tennessee Valley
Beginning in June 1984, the Tennessee Valley region entered the most severe, extended period of drought since record keeping began in 1890. The historical annual average rainfall across...
Review of Mitigation Methods for Fish Passage, Instream Flows, and Water Quality
Current environmental mitigation practices at nonfederal hydropower projects were analyzed. Information was obtained from project operators on dissolved oxygen (DO) mitigation, instream...
Factors Affecting Dissolved Oxygen in Hydropower Reservoirs
Dissolved oxygen (DO) is becoming a significant issue for hydropower projects. This paper identifies some key factors that can help hydropower operators better understand the nature of...
Side Effect of the Cross-Flow Turbine: Improved Water Quality
The working principle of the Original Cross-Flow Turbine with draft tube demands air induced into the turbine housing to operate at high efficiency. Reoxygenation of water will occur,...
The Gloryhole Approach to Increasing Dissolved Oxygen Content
Deep intakes at hydroelectric dams in southern states withdraw water that is oxygen deficient during summer months when reservoirs become stratified. The 'Gloryhole'...
Deflector Plate Turbine Aeration?Case Studies
Water quality requirements have become a focal point in recent re-licensing of hydroelectric projects. The Federal Energy Regulatory Commission has significantly increased the relevance...
Stream Water Quality Modeling in Ankara Metropolitan Area
At the time this study was undertaken, untreated wastewaters from Ankara metropolitan area (capital of Turkish Republic) were being discharged directly into Ankara Creek and its tributaries....
Tailwater Concerns and the History of Turbine Aeration
All new proposals for hydropower development and many of the almost 300 hydroelectric projects which will be relicensed before 2000 will have to address the issue of minimum dissolved...
Overview of Autoventing Turbine Technology Development Project
Low concentrations of dissolved oxygen (DO) in the discharge of hydro plants represent one of the most significant environmental concerns confronting the hydropower industry. This is especially...
Model Tests for the Evaluation of Auto-Venting Hydroturbines
The most significant environmental problem for many hydroelectric facilities is the water quality of turbine discharges. The primary water quality problem is often low dissolved oxygen...
Experimental Difficulties Encountered in Testing Air/Water Mixtures
The Tennessee Valley Authority and Voith Hydro, Inc., are conducting a joint research project to study the effects of air admission on hydraulic turbines. Francis turbine models, homologous...
Energy Losses Due to Air Admission in Hydroturbines
Admission of air at the exit of a hydroturbine runner is an attractive technique for raising dissolved oxygen levels downstream of a hydro plant. The air admission, however, is generally...
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