Observation of Single Transits in Supercooled Monatomic Liquids

A transit is the motion of a system from one many-particle potential energy valley to another. We report the observation of transits in molecular dynamics (MD) calculations of supercooled liquid argon and sodium. Each transit is a correlated simultaneous shift in the equilibrium positions of a small local group of particles, as revealed in the fluctuating graphs of the particle coordinates versus time. This is the first reported direct observation of transit motion in a monatomic liquid in thermal equilibrium. We found transits involving 2 to 11 particles, having mean shift in equilibrium position on the order of 0.4 R_1 in argon and 0.25 R_1 in sodium, where R_1 is the nearest neighbor distance. The time it takes for a transit to occur is approximately one mean vibrational period, confirming that transits are fast.Comment: 19 pages, 8 figure

Metal alloy resistivity measurements at very low temperatures

High speed, automated system accurately measures to approximately one percent in three minutes. System identifies materials having constant thermal or electric conductivity, predicts new material properties, develops alloys in accordance with desired specifications, and develops nondestructive devices for measuring precipitation hardening

A farm creaming experiment

A short time ago we were asked whether any injustice would result to either creamery-man or patron, if the latter should set his evening’s milk, skim it in the morning, mix the cream with the morning’s milk and send the mixture to the creamery instead of sending the milk of both evening and morning, as is the usual custom. The most satisfactory way to answer all such queries is by practical demonstrations, and it was determined to conduct an experiment bearing on the point in question. A short time ago we were asked whether any injustice would result to either creamery-man or patron, if the latter should set his evening’s milk, skim it in the morning, mix the cream with the morning’s milk and send the mixture to the creamery instead of sending the milk of both evening and morning, as is the usual custom. The most satisfactory way to answer all such queries is by practical demonstrations, and it was determined to conduct an experiment bearing on the point in question

Low-energy interaction of composite spin-half systems with scalar and vector fields

We consider a composite spin-half particle moving in spatially-varying scalar and vector fields. The vector field is assumed to couple to a conserved charge, but no assumption is made about either the structure of the composite or its coupling to the scalar field. A general form for the piece of the spin-orbit interaction of the composite with the scalar and vector fields which is first-order in momentum transfer ${\bf Q}$ and second-order in the fields is derived.Comment: 10 pages, RevTe

Wind Tunnel Investigation of the Effect of Jet-Motor Operation Stability

The effects of jet-motor operation on the stability and control characteristics of two fighter-type airplanes as determined by wind-tunnel tests of 1/5-scale models are presented. It is shown that the action of the jets is to cause a small loss in stick-fixed stability which is predictable from known theories