Lunar soil properties and soil mechanics

The long-range objectives were to develop methods of experimentation and analysis for the determination of the physical properties and engineering behavior of lunar surface materials under in situ environmental conditions. Data for this purpose were obtained from on-site manned investigations, orbiting and softlanded spacecraft, and terrestrial simulation studies. Knowledge of lunar surface material properties are reported for the development of models for several types of lunar studies and for the investigation of lunar processes. The results have direct engineering application for manned missions to the moon

FLUORINE DISPOSAL USING CHARCOAL

Wood, coke, and coconut-shell charcoals were evaluated for fluorine entrapment. The coconut-shell charcoal produced the smallest amount of solid and liquid reaction products. Efficient removal of fluorine was accomplished by the coconut-shell charcoal in a 5-in.-diameter reactor with a feed containing 25% fluorine at flow rates from 100 to 400 scfh and reactor-wall temperatures of 1200 to 1800 deg F. (C.J.G.

Investigation of Hole Caving Due to Vibrations

Foundations for a power plant were constructed by drilling holes in cemented sand for 36 piers. The boreholes in the cemented sand did not cave. A major design change required the demolition of the original piers and pile caps with large hoe rams and the drilling of new 36 boreholes in the same location. The new drilling contractor experienced widespread caving, which he was unable to remedy. The authors first investigated the possibility that the second contractor used inferior equipment or techniques. Then the authors investigated the possibility that a loss in soil cohesion occurred due to the vibrations from pier/pile cap demolition and casing installation. Analyses performed included (1) peak particle velocity evaluation, (2) laterally loaded pile/fatigue analysis, and (3) finite element analysis. It was concluded that significant loss of cohesion due to these vibrations was plausible and that the loss of cohesion could account for the bole caving

Lunar surface engineering properties experiment definition Quarterly report, 1 Oct. - 31 Dec. 1968

Mechanical properties of simulated lunar soil

Experimental demonstration of painting arbitrary and dynamic potentials for Bose-Einstein condensates

There is a pressing need for robust and straightforward methods to create potentials for trapping Bose-Einstein condensates which are simultaneously dynamic, fully arbitrary, and sufficiently stable to not heat the ultracold gas. We show here how to accomplish these goals, using a rapidly-moving laser beam that "paints" a time-averaged optical dipole potential in which we create BECs in a variety of geometries, including toroids, ring lattices, and square lattices. Matter wave interference patterns confirm that the trapped gas is a condensate. As a simple illustration of dynamics, we show that the technique can transform a toroidal condensate into a ring lattice and back into a toroid. The technique is general and should work with any sufficiently polarizable low-energy particles.Comment: Minor text changes and three references added. This is the final version published in New Journal of Physic

Measuring atomic NOON-states and using them to make precision measurements

A scheme for creating NOON-states of the quasi-momentum of ultra-cold atoms has recently been proposed [New J. Phys. 8, 180 (2006)]. This was achieved by trapping the atoms in an optical lattice in a ring configuration and rotating the potential at a rate equal to half a quantum of angular momentum . In this paper we present a scheme for confirming that a NOON-state has indeed been created. This is achieved by spectroscopically mapping out the anti-crossing between the ground and first excited levels by modulating the rate at which the potential is rotated. Finally we show how the NOON-state can be used to make precision measurements of rotation.Comment: 14 preprint pages, 7 figure

Lunar surface engineering properties experiment definition. Volume 1: Mechanics, properties, and stabilization of lunar soils

Lunar soil simulation and stabilization, and impact penetrometer studie

An adaptive variable order quadrature strategy

In this article we propose a new adaptive numerical quadrature procedure which includes both local subdivision of the integration domain, as well as local variation of the number of quadrature points employed on each subinterval. In this way we aim to account for local smoothness properties of the function to be integrated as effectively as possible, and thereby achieve highly accurate results in a very efficient manner. Indeed, this idea originates from so-called hp-version finite element methods which are known to deliver high-order convergence rates, even for nonsmooth functions

Landau-Zener transitions in a linear chain

We present an exact asymptotic solution for electron transition amplitudes in an infinite linear chain driven by an external homogeneous time-dependent electric field. This solution extends the Landau-Zener theory for the case of infinite number of states in discrete spectrum. In addition to transition amplitudes we calculate an effective diffusion constant.Comment: 3 figure