Mechanics of Granular Materials at Very Low Effective Stress Levels
Gravity's influence on laboratory specimens of uncemented granular materials subjected to low effective stresses, makes it impossible to evaluate constitutive properties in an unambiguous...

Influence of Gas Phase Turbulence on the Transport of Particles
An interesting and perhaps unexpected flow feature characterizing the transport of a gas-solid suspension in a vertical duct is the radial nonuniformity of particles over the tube cross-section....

Structural Characterization of an Articulated-Truss Joint
A first generation space crane articulated-truss joint was statically and dynamically characterized in a configuration which approximated an operational environment. The articulated-truss...

Mechanical Properties of Lunar Soil and Simulants
Investigation of the physical and mechanical properties of lunar soil carried out by the USSR and the USA; both in situ and on returned samples, has resulted in considerable information...

Hydrogen Reduction of Lunar Soil and Simulants
Carbotek, Inc., and the Energy and Environmental Research Center (EERC) are cooperating on further development of the Carbotek process to produce oxygen from lunar ilmenite by hydrogen...

Structural Considerations in the Design of a Mars Mission Aerobrake
A new area of civil engineering is emerging. This area will provide structures for outposts on the moon, resource development and exploration of Space. Spacecraft traveling at very high...

Vacuum Melting and Mechanical Testing of Simulated Lunar Glasses
Lunar silicate glasses may possess superior mechanical properties compared to terrestrial glasses because the anhydrous lunar environment should prevent hydrolytic weakening of the strong...

Mechanical Properties of Compacted Lunar Simulant Using New Vacuum Triaxial Equipment
Mechanical stress-strain-strength properties of Arizona Lunar Simulant (ALS) are investigated by using a newly developed vacuum triaxial device that allows compaction under different initial...

An Analysis of Human Performance in Simulated Partial-Gravity Environments
Three unique partial gravity test environments; parabolic flight, water immersion and a mechanical-relief device provide the environment to evaluate human locomotion, reach sweeps, and...

A PC Modelling System for the Simulation of Transport and Fate of Solutes and Suspended Substances
PARTICLE is a numerical computer model for the simulation of transport and fate of discharged, dissolved or suspended substances. The model is based upon the Lagrangian approach and calculates...

Continuum Model for Flows in Emergent Marsh Vegetation
Modeling of flows in tidal marshes requires modifications to the classical equations of open channel flow. In this study, the authors formulate an equivalent continuum model for tidal...

Modeling the Pathways of Nonconservative Substances in Estuaries
ELAmet is a model for nonconservative chemical transport which solves the advection/dispersion/transformation equation using a modification of Eulerian-Lagrangian methods. In this paper...

3-D Modelling of Heat Discharge from Ul-Jin Power Plant into Coastal Waters of Korea East Sea
This study focuses on the problems of simulating the coastal currents and their effect on the distribution of heated cooling water from the Ul-Jin power plant into coastal waters of Korea...

A Modified Adjoint Method for Inverse Eddy Viscosity Estimation for Use in Coastal Circulation Models
The adjoint method is used to develop an objective analysis technique for estimating the vertical eddy viscosity used in three dimensional oceanic models. A cost functional which consists...

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...

Stochastic Dynamics of Hysteretic Systems
A frequency domain method is discussed in order to evaluate the second order statistical response of nonlinear hysteretic structures. Both shear type systems and lumped mass frames involving...

Variability Response Functions and Stochastic Field Discretization in Stochastic Finite Element Methods
Stochastic systems whose mechanical properties vary spatially are investigated in the present paper. The stochastic response variability of the systems is characterized by means of the...

Responses of Nonlinear Oscillators Excited by Non-Gaussian Pulse Processes
The estimation of the response statistics of nonlinear systems subjected to Poisson-distributed pulse processes is addressed. The procedure to be followed is based on an extension of the...

Earthquake Ground Motion Modeling with Stochastic Line Source
Principles of geophysics and stochastics are applied to develop an earthquake model, in which the earth medium is idealized as consisting of stratified elastic layers, responding to seismic...

Site-Dependence of Spatial Coherency
The spatial coherency of ground motion from nine dense arrays are analyzed to examine the site-dependence of spatial coherency. The spatial coherencies computed for arrays located on alluvium...

 

 

 

 

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