A Comparison of Propulsion Systems for Space Exploration
There are three promising propulsion systems that might be used for space missions: chemical, direct nuclear, and nuclear electric. Selecting the best system for a mission involves comparing...
Reducing the Long-Term Effects of Zero-Gravity
Maintaining the physical health of scientists has been a longstanding problem in space flight research. Several ideas have been proposed to solve this problem. These include creating artificial...
Spacecab: A Concept for Commercial Human Spaceflight
This paper will describe the Spacecab conceptual design and operational scenario. Spacecab is not necessarily a unique design solution but it does illustrate a design philosophy that differs...
Synthetic Estimation of Development Cost of Satellite
An analysis and estimation of life cycle cost (LCC) is one of the important parts of a conceptual study or feasibility study on a satellite....
Engineering R&D Strategy
Accurate data on the levels and focus of U.S. civil engineering-related R&D are important to establish a benchmark from which a knowledge base can be constructed; to highlight...
Current State of Development and Future Trends in Employment of Air-Supported Roofs in Long-Span Applications
Considered here is the low-profile, long span air-supported roof, as opposed to the high-profile 'bubble' variety, which has seen a substantially different development and expectation....
Checking of CAD Drawings for Fabrication Issues
Communication between the fabricator and engineer is crucial to the production of an economical, safe, and functional steel structure. However, the transfer of information between involved...
ASCE Salary Survey 1993
The 22nd biennial ASCE salary survey of the engineering profession conducted by the ASCE Committee on Employment Conditions during the first half of 1993 is presented. It consists of an...
Rehabbing for Remediation
Workers for Moses Lake detected trichloroethylene (TCE) in three of the city's water wells. The concentrations were low, around 5 to 15 parts per billion, just above the maximum...
Federal Cleanups: Good News from Bad
Since the end of the Cold War the news about the Department of Energy has been grim: Thousands of acres poisoned with radioactive and toxic wastes, massive cleanup cost overruns due to...
Cost Considerations in Planning Pier Terminals
The deregulation of the air transport economy is gradually leading to the involvement of private developers in airport terminal financing. Even the airports run by government agencies...
Optimal Groundwater Reclamation with Captial Costs
A dynamic optimal control model for groundwater remediation was extended to incorporate treatment facility capital costs. Incorporation of the capital costs had the greatest impact on...
Aquifer Remediation Design: Nonlinear Programming and Genetic Algorithms
Nonlinear programming and genetic algorithm solutions of a pump-and-treat aquifer remediation design model are presented and discussed. These models find the minimum cost design of the...
Arizona Groundwater Management Alternatives
Sustainable groundwater management policies are examined through the use of a hydrologic-economic impact model of Arizona surface and groundwater use. Present water use practices were...
Effectiveness of Retrofit in Multi-Family Apartments
This paper reports the results of an evaluation research study of the cost-effectiveness of water-conserving, residential retrofit plumbing devices. By means of a 'quasi-experimental,'...
Designing Under Uncertainty When We Can Reduce Uncertainty: When is Another Observation Worth the Cost?
A method is presented that optimizes the selection of sites for observation of an uncertain parameter when that parameter is used in the risk-based design of an engineered system. The...
Water and Wildlife Enhancement with Land Retirement
This case analysis compares costs of land retirement and current on-going structural improvements for salinity reduction in the Colorado River. Results suggest land retirement programs...
The Economic Cost of Stocking Catchable Rainbow Trout
States annually stock about 20 million pounds of catchable trout in public waters. Complete information on cost is essential to help wildlife agencies make operating and planning decisions....
Activity Based Costing in Water Resources Management
This paper examines the relatively new accounting tool, Activity Based Costing (ABC), and describes its potential application in water resources planning, management, and operations. The...
Development of Missouri River Navigation Analysis
The navigation analysis for the Master Manual review examined mainstem reservoir regulation alternatives by evaluating the benefits of reservoir releases for barge transportation. Navigation...
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