One-Dimensional Radionuclide Transport Under Time-Varying Conditions
New analytical and numerical solutions are presented for one-dimensional radionuclide transport under time-varying fluid-flow conditions including radioactive decay. The analytical solution...

A Gas-Flow Source Term from a Nuclear Waste Container in an Unsaturated Medium
The potential nuclear waste repository at Yucca Mountain is to be in partially saturated rock. Released radioactive gases would have a direct pathway to the biosphere. The entry of air...

Permeability and Dispersivity of Variable-Aperture Fracture Systems
A number of recent experiments have pointed out the need of including the effects of aperture variation within each fracture in predicting flow and transport properties of fractured media....

A Stratified Percolation Model for Saturated and Unsaturated Flow Through Natural Fractures
The geometry of the asperities of contact between the two surfaces of a fracture and of the adjacent void spaces determines fluid flow through a fracture and the mechanical deformation...

Study of Fractal Aperture Distribution and Flow in Fractures
This study examines the roughness profiles and aperture distributions of fractures and faults by using concepts from fractal geometry. Simple models of flow of fluid in rough fractures...

Geochemical Modeling: An Integrated Approach to Nuclear Waste Disposal Issues
To meet nuclear waste repository licensing requirements, the response of repository components and of the enclosing host rocks and fluids to temperature fluctuations, fluid flow, radionuclide...

Simulation of Heat Transfer in the Unsaturated Zone
It is well known that heat transfer can play an important roll in fluid flow near the emplacement site of high-level nuclear waste (K. Pruess and J.S.W. Wang, 1987). Heat transfer effects...

Combined Analytical/Numerical Approaches to Solving Fluid Flow Problems in the Unsaturated Zone at Yucca Mountain
Various analytical and numerical approaches are presented for the study of unsaturated flow processes in the vicinity of the Yucca Mountain, Nevada, the proposed site of an underground...

Modeling of Coupled Heat-Mass-Stress Effects in Geologic Media
To investigate the importance of coupled hydraulic-thermal-mechanical processes for the potential nuclear waste storage repository at the Yucca Mountain, a computer code is being developed....

Fluid Line Deployment and Repair for Space Station
Deployment of the utility system for providing services to the NASA Space Station Freedom provides a unique challenge in design and material technology. The system must be lightweight,...

Clearing Space Debris Using Energetic Materials
Space debris is growing at an alarming rate. It consists not only of old, unusable payloads but also aluminum oxide combustion products of various space delivery systems and small fragments...

Post-MECO Propulsion System Requirements for Placement of an STS External Tank in Low Earth Orbit
This paper discusses the findings of a series of computer simulations carried out at the National Institute of Standards and Technology to investigate the requirements for powered flight...

Investigation of HVAC Systems in Low Gravity Application
This paper has been developed to identify and summarize the principal areas of investigation necessary to design and install functional HVAC systems in low gravity applications. These...

Fluid Behavior Considerations for Waste Management in Low-Gravity Environments
Design of waste recycling systems for spacecraft requires a knowledge of fluid behavior in microgravity. As gravity is reduced, phenomena usually ignored in the One-G environment of earth...

Design Considerations for a Ceramic Fabric Radiator
The design of an Advanced Ceramic Fabric (ACF) thermal management device for use in both interplanetary and near-earth space must consider several important aspects of the environment....

Identification of Aquifer Parameters in Confined Groundwater Flow
The logarithm of the aquifer properties, log transmissivity (log T) and log storativity (log S), are regarded as realizations of stochastic processes whose estimates are required. The...

Flownets by Computer Graphics
A new method of drawing flownets for determining seepage losses in earth dams is developed. The flow and equipotential lines are drawn by modifying W. Kinzelbagh's method....

Flow Separation of Currents in Shallow Water
Flow separation of currents in shallow coastal areas is investigated using a boundary layer model for two-dimensional (depth-averaged) tidal flow past an elliptic headland. If the shoaling...

Calibration of a Transport Model Using Halocarbons
A field study was conducted during April 1987 in which the concentrations of volatile halocarbon tracers, discharged from two existing outfalls, were measured throughout Boston Harbor...

Comparison of Computed and Observed Velocities at Three Estuarine Sites
The Generalized, Longitudinal-Vertical Hydrodynamic and Transport model (GLVHT) has been applied to the Patuxent River estuary, the Raritan River Estuary and the Arthur Kill. The applications...

 

 

 

 

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