Statistical summary: Study to determine the IFR operational profile of the general aviation single pilot

The statistical summary of data resulting from a mail questionnaire survey designed to develop information on the general aviation single pilot operating under instrument flight rules is presented

Beliefs about brain injury in Britain

Primary objective: Surveys have revealed that a high proportion of the public in the US and Canada hold misconceptions pertaining to the sequelae of brain injury. This study examined whether similar misconceptions are endorsed by adults in Britain. Research design: Survey. Methods and procedures: Three hundred and twenty-two participants completed a 17-item questionnaire containing true or false statements about general knowledge of brain injury, coma and consciousness, memory impairments and recovery. Main outcomes and results: Regardless of age, sex, level of education and familiarity with brain injury, participants held mistaken beliefs about consciousness, were inclined to under-estimate the extent of memory deficits and were unaware that patients are more vulnerable and less resistant to further injury. A large proportion of respondents indicated that their knowledge of brain injury had been derived from the popular media. Conclusions: Similar misconceptions to those reported in previous studies exist in Britain. Notably in this study these misconceptions were endorsed by a greater percentage of respondents. Greater public awareness is needed for decisions concerning funding and patient care. It is therefore important for healthcare professionals and public health campaigns to dispel myths about brain injury

Technical summary of accomplishments made in preparation for the USSR barley exploratory experiment

The highlights of the work accomplished under each subcomponent of the U.S.S.R. Barley Pilot Experiment, which is scheduled for completion in 1984, are summarized. A significant amount of developmental system implementation activity was in the final stages of preparation prior to the rescoping of project tasks. Unpublished materials which are significant to this exploratory experiment are incorporated into the appendixes

The stability of charged-particle motion in sheared magnetic reversals

We consider the motion of charged particles in a static magnetic reversal with a shear component, which has application for the stability of current sheets, such as in the Earth's geotail and in solar flares. We examine how the topology of the phase space changes as a function of the shear component by. At zero by, the phase space may be characterized by regions of stochastic and regular orbits (KAM surfaces). Numerically, we find that as we vary by, the position of the periodic orbit at the centre of the KAM surfaces changes. We use multiple-timescale perturbation theory to predict this variation analytically. We also find that for some values of by, all the KAM surfaces are destroyed owing to a resonance effect between two timescales, making the phase space globally chaotic. By investigating the stability of the solutions in the vicinity of the fixed point, we are able to predict for what values of by this happens and when the KAM surfaces reappear

Comment on Bramwell et al, "Universal Fluctuations in Correlated Systems"

This is a comment on "Universal Fluctuations in Correlated Systems", by Bramwell et al, Phys. Rev. Lett., 84, 3744 (2000.Comment: To appear in Phys. Rev. Let

Flight and ground tests of a very low density elastomeric ablative material

A very low density ablative material, a silicone-phenolic composite, was flight tested on a recoverable spacecraft launched by a Pacemaker vehicle system; and, in addition, it was tested in an arc heated wind tunnel at three conditions which encompassed most of the reentry heating conditions of the flight tests. The material was composed, by weight, of 71 percent phenolic spheres, 22.8 percent silicone resin, 2.2 percent catalyst, and 4 percent silica fibers. The tests were conducted to evaluate the ablator performance in both arc tunnel and flight tests and to determine the predictability of the albator performance by using computed results from an existing one-dimensional numerical analysis. The flight tested ablator experienced only moderate surface recession and retained a smooth surface except for isolated areas where the char was completely removed, probably following reentry and prior to or during recovery. Analytical results show good agreement between arc tunnel and flight test results. The thermophysical properties used in the analysis are tabulated