Solid state studies in ceramic alloys Quarterly progress report, 1 Jun. - 31 Aug. 1969

Solid state characteristics of ceramic alloy

Low temperature specific heat of vanadium carbide

Low temperature specific heat measurements on vanadium carbide crystal

Bonding, structure and mechanical behavior of vanadium carbide single crystals

Bonding, structure, and mechanical behavior of vanadium carbide single crystal

Confidence Intervals for Estimates of Elasticities

Elasticities are often estimated from the results of demand analysis however, drawing inferences from them may involve assumptions that could influence the outcome. In this paper we investigate one of the most common forms of elasticity which is defined as a ratio of estimated relationships and demonstrate how the Fieller method for the construction of confidence intervals can be used to draw inferences. We estimate the elasticities of expenditure from Engel curves using a variety of estimation models. Parametric Engel curves are modelled using OLS, MM robust regression, and Tobit. Semiparametric Engel curves are estimated using a penalized spline regression. We demonstrate the construction of confidence intervals of the expenditure elasticities for a series of expenditure levels as well as the estimated cumulative density function for the elasticity evaluated for a particular household.Engel curves, Fieller method, Tobit, robust regression, semiparametric

Magnetic susceptibility of vanadium carbide

Magnetic susceptibility of vanadium carbide from 77 to 300 K measured by magnetomete

A Bose-Einstein condensate in a random potential

An optical speckle potential is used to investigate the static and dynamic properties of a Bose-Einstein condensate in the presence of disorder. For strong disorder the condensate is localized in the deep wells of the potential. With smaller levels of disorder, stripes are observed in the expanded density profile and strong damping of dipole and quadrupole oscillations is seen. Uncorrelated frequency shifts of the two modes are measured for a weak disorder and are explained using a sum-rules approach and by the numerical solution of the Gross-Pitaevskii equation

Quality of Condensate from Air-Handling Units

Areas with humid climates, such as Georgia, are currently experiencing a severe drought. Collecting condensate from large AHUs for on-site use is compelling, but how do you assess the quality of this water? The authors discuss how condensate from properly maintained large AHUs is high-quality water. They go on to explain how system design and maintenance affect its quality, and they give the readers guidance for how to use the condensate for on-site application

Effect of optical disorder and single defects on the expansion of a Bose-Einstein condensate in a one-dimensional waveguide

We investigate the one-dimensional expansion of a Bose-Einstein condensate in an optical guide in the presence of a random potential created with optical speckles. With the speckle the expansion of the condensate is strongly inhibited. A detailed investigation has been carried out varying the experimental conditions and checking the expansion when a single optical defect is present. The experimental results are in good agreement with numerical calculations based on the Gross-Pitaevskii equation.Comment: 5 pages, 5 figure

Classical noise and flux: the limits of multi-state atom lasers

By direct comparison between experiment and theory, we show how the classical noise on a multi-state atom laser beam increases with increasing flux. The trade off between classical noise and flux is an important consideration in precision interferometric measurement. We use periodic 10 microsecond radio-frequency pulses to couple atoms out of an F=2 87Rb Bose-Einstein condensate. The resulting atom laser beam has suprising structure which is explained using three dimensional simulations of the five state Gross-Pitaevskii equations.Comment: 4 pages, 3 figure

Unstable regimes for a Bose-Einstein condensate in an optical lattice

We report on the experimental characterization of energetic and dynamical instability, two mechanisms responsible for the breakdown of Bloch waves in a Bose-Einstein condensate interacting with a 1D optical lattice. A clear separation of these two regimes is obtained performing measurements at different temperatures of the atomic sample. The timescales of the two processes have been determined by measuring the losses induced in the condensate. A simple phenomenological model is introduced for energetic instability while a full comparison is made between the experiment and the 3D Gross-Pitaevskii theory that accounts for dynamical instability