The simulation of aerial movement—IV. A computer simulation model

A computer simulation model of human airborne movement is described. The body is modelled as 11 rigid linked segments with 17 degrees of freedom which are chosen with a view to modelling twisting somersaults. The accuracy of the model is evaluated by comparing the simulation values of the angles describing somersault, tilt and twist with the corresponding values obtained from film data of nine twisting somersaults. The maximum deviations between simulation and film are found to be 0.04 revolutions for somersault, seven degrees for tilt and 0.12 revolutions for twist. It is shown that anthropometric measurement errors, from which segmental inertia parameters are calculated, have a small effect on a simulation, whereas film digitization errors can account for a substantial part of the deviation between simulation and film values

Pulsar-wind nebulae and magnetar outflows: observations at radio, X-ray, and gamma-ray wavelengths

We review observations of several classes of neutron-star-powered outflows: pulsar-wind nebulae (PWNe) inside shell supernova remnants (SNRs), PWNe interacting directly with interstellar medium (ISM), and magnetar-powered outflows. We describe radio, X-ray, and gamma-ray observations of PWNe, focusing first on integrated spectral-energy distributions (SEDs) and global spectral properties. High-resolution X-ray imaging of PWNe shows a bewildering array of morphologies, with jets, trails, and other structures. Several of the 23 so far identified magnetars show evidence for continuous or sporadic emission of material, sometimes associated with giant flares, and a few possible "magnetar-wind nebulae" have been recently identified.Comment: 61 pages, 44 figures (reduced in quality for size reasons). Published in Space Science Reviews, "Jets and Winds in Pulsar Wind Nebulae, Gamma-ray Bursts and Blazars: Physics of Extreme Energy Release

Yacht sail aerodynamics Part 2; achievable mainsail specification

SIGLEAvailable from British Library Document Supply Centre- DSC:5294.94(LUT-TT--8904) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Yacht sail aerodynamics Part 1; optimising overall performance

SIGLEAvailable from British Library Document Supply Centre- DSC:5294.94(LUT-TT--8903) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Yacht sail aerodynamics Part 3; achievable jibsail specification

SIGLEAvailable from British Library Document Supply Centre- DSC:5294.94(LUT-TT--8905) / BLDSC - British Library Document Supply CentreGBUnited Kingdo