Atomic Beams

Contains a report on a research project.Lincoln Laboratory (Purchase Order DDL-B222)United States Department of the ArmyUnited States Department of the NavyUnited States Department of the Air Force (Contract AF19(122)-458

The Challenge of Pulmonary Emphysema

I feel very privileged to be invited to be your Stoneburner Lecturer for this year. When I came to consider what I really wanted to say and what might interest people in widely different areas of medicine, there really was little choice. I perhaps can claim to be able to talk about emphysema from a rather broad standpoint than some other physicians. Not because I suffer from it, which is sometimes a good reason for talking about a disease, but because I have been trained both in England and in America, and the outlook on this disease has differed in Europe and in the States

Design study of general aviation collision avoidance system

The selection and design of a time/frequency collision avoidance system for use in general aviation aircraft is discussed. The modifications to airline transport collision avoidance equipment which were made to produce the simpler general aviation system are described. The threat determination capabilities and operating principles of the general aviation system are illustrated

The Modern Treatment of Respiratory Failure

I suppose it is appropriate that we come to respiratory failure at the end of a longish day. The definition of respiratory failure has an interesting history. Barcroft, 30 to 40 years ago, understood respiratory failure as a tissue phenomenon. He would have described cyanide poisoning to you as an example of respiratory failure. Ventilatory failure came into fashion but is not a very good term because total ventilation may be fine but gas exchange may be very poor. Europeans have invented various terms like global insufficiency, which sounds very impressive in German, but always sounds to me more like a term from the Pentagon than a medical or physiological definition. I prefer to use the term respiratory failure to mean everything related to disordered gas tensions; but if you attempt a precise definition, you run into unexpected difficulties

Toroidal Vortices in Resistive Magnetohydrodynamic Equilibria

Resistive steady states in toroidal magnetohydrodynamics (MHD), where Ohm's law must be taken into account, differ considerably from ideal ones. Only for special (and probably unphysical) resistivity profiles can the Lorentz force, in the static force-balance equation, be expressed as the gradient of a scalar and thus cancel the gradient of a scalar pressure. In general, the Lorentz force has a curl directed so as to generate toroidal vorticity. Here, we calculate, for a collisional, highly viscous magnetofluid, the flows that are required for an axisymmetric toroidal steady state, assuming uniform scalar resistivity and viscosity. The flows originate from paired toroidal vortices (in what might be called a ``double smoke ring'' configuration), and are thought likely to be ubiquitous in the interior of toroidally driven magnetofluids of this type. The existence of such vortices is conjectured to characterize magnetofluids beyond the high-viscosity limit in which they are readily calculable.Comment: 17 pages, 4 figure