Development of a low temperature battery for space probe applications second quarterly report, 24 sep. - 23 dec. 1964

Low temperature battery for space prob

Generation of Particles and Seeding

One of the most important elements in laser velocimetry, yet the most neglected, is the small particle embedded in the flow field that scatters the light necessary to make velocity measurements. An attempt to remove the confusion in choosing a seeding method by assessing many of the techniques currently used is presented. Their characteristics and typical limitations imposed by various applications are outlined. The ramifications of these methods on measurement accuracy are addressed

Frequency domain laser velocimeter signal processor

A new scheme for processing signals from laser velocimeter systems is described. The technique utilizes the capabilities of advanced digital electronics to yield a signal processor capable of operating in the frequency domain maximizing the information obtainable from each signal burst. This allows a sophisticated approach to signal detection and processing, with a more accurate measurement of the chirp frequency resulting in an eight-fold increase in measurable signals over the present high-speed burst counter technology. Further, the required signal-to-noise ratio is reduced by a factor of 32, allowing measurements within boundary layers of wind tunnel models. Measurement accuracy is also increased up to a factor of five

Non-Gaussianities in Multifield Inflation: Superhorizon Evolution, Adiabaticity, and the Fate of fnl

We explore the superhorizon generation of large fnl of the local form in two field inflation. We calculate the two- and three-point observables in a general class of potentials which allow for an analytic treatment using the delta N formalism. Motivated by the conservation of the curvature perturbation outside the horizon in the adiabatic mode and also by the observed adiabaticity of the power spectrum, we follow the evolution of fnl^{local} until it is driven into the adibatic solution by passing through a phase of effectively single field inflation. We find that although large fnl^{local} may be generated during inflation, such non-gaussianities are transitory and will be exponentially damped as the cosmological fluctuations approach adiabaticity.Comment: v3: Typos corrected, minor changes to match published version, references added, 18 pages, 1 figure. v2: Changed sign of fnl to match WMAP convention, minor changes throughout, references added, 18 pages, 1 figure. v1: 17 pages, 1 figur

Janeisms

In the May 1980 Kickshaws, Charles Bostick introduced a variety of wordplay called Ravenisms in which one mixes cliches like mad as a wet hatter (mad as a wet hen, mad as a hatter) don\u27t burn your bridges at both ends (don\u27t burn your bridges behind you, don\u27t burn the candle at both ends) put one\u27s oar in the ring (put in one\u27s oar, throw one\u27s hat in the ring)