A Modified Sulfate Process to Lunar Oxygen
A modified sulfate process which produces oxygen from iron oxide-bearing minerals in lunar soil is under development. Reaction rates of ilmenite in varying strength sulfuric acid have...

Steady State Composition with Low Fe?+ Concentrations for Efficient O2 Production by Magma Electrolysis of Lunar Soils
Parameters are estimated for a hypothetical, well stirred, continuous-feed electrolytic cell that converts 20% of a lunar soil feedstock to O2 gas,...

Beneficiation of Lunar Rocks and Regolith: Concepts and Difficulties
Considerations of the resources which can provide feedstocks of ilmenite, glass, agglutinates, anorthite, etc. at a lunar base require an appreciation of the geology of the situation....

Regolith Dynamics
Due to the differences of the gravitational accelerations of the Earth and Lunar environments, geotechnical engineering must be applied differently in the two environments. This study...

Principles of Control for Robotic Excavation
Excavation can be considered one of the most unstructured problems in the construction environment. On one hand, many technologies have been developed in the past to build shelters using...

Laboratory Evaluation of Footings for Lunar Telescopes
Presented here are the results of laboratory experiments with different footing shapes for lunar telescopes. These experiments used a variety of soils including some to simulate regolith...

Plot-scale Field Experiment of Surface Hydrologic Processes with EOS Implications
Plot-scale hydrologic field studies were initiated at NASA Marshall Space Flight Center to a) investigate the spatial and temporal variability of surface and subsurface hydrologic processes,...

Better Cover-Ups
Designing the final cover for a solid waste landfill or remediation site is often trickier than designing its lining because a cover will undergo more unpredictable stress and distress...

Earthquake Considerations in Earth Dam Design
In 1963, the writer was engaged by the State of California Department of Water Resources to make a study of the influence of the hazard of earthquakes on the design of embankment type...

Piping in Earth Dams of Dispersive Clay (Paper introduced by Norman L. Ryker)
In 1971 Jim Sherard was engaged to investigate the common failure of a group of Soil Conservation Service (SCS) floodwater retarding earthfill dams built between 1957 and 1970, eleven...

Land Use, Transportation and Air Quality Relationships
Increasing land development densities and reducing suburban sprawl is frequently considered as a tool to reduce vehicle miles of travel and resultant air pollution emissions. Two studies...

Surface Motion Due to Stochastic Plane Sources in a Layered Medium
To simulate the ground motion in the near field, a seismic fault is modeled as a two-strip plane. The width of each strip is so thin that the rupture process of the strip can be described...

Evaluation of Expansive Clay Soils in Tucson, Arizona
Research was conducted to investigate the mineralogy, engineering properties, and regional distribution of expansive clay soils in Tucson, Arizona. Data derived from X-ray diffraction...

Geotechnical Database Manipulation to Effect Stochastic Analysis
Existing or easily-developed databases of regional geotechnical information can be used to estimate prior probability distributions and parameters for use in stochastic analyses. Prior...

Predicting Effects of Subsidence on Landfill Caps
Groundwater protection at unlined, closed landfills relies upon limiting cover or cap infiltration. Depressions on closed landfills indicate infiltration from reduced runoff and loss of...

A Knowledge Based System with Uncertainty for the Soil
In this paper, we present the methodology that we used to develop the KBSOL Knowledge Based System for the soil. We describe the structure that contains the objects of the domain (layer,...

Seismic Response Variability of Soil Sites
The seismic response variability of soil sites due to randomness associated with both the input base motion and spatial inhomogeneity of the shear modulus is investigated. Some numerical...

Soil/Structure Seismic Investigation of Safety-Related Structures
This paper promotes an improved understanding of the type of earthquake motions felt at V.C. Summery, Perry and Krsko nuclear power plants. An analytical investigation is performed to...

Differential Motions in Sedimentary Valleys
The differential motions (strains), induced in sediment-filled valleys due to incident seismic waves, are investigated. The response of a two-dimensional model of an asymmetric wedge-shaped...

Probabilistic Particle-Related Constitutive Model for Clayey Material
Particle-related (microscopic) soil modeling has attracted attention of research community in recent years, because of complication and shortcoming associated with inelastic macroscopic...

 

 

 

 

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