Introduction: Polarisation mode dispersion (PMD) is an important factor in the performance of long-distance high speed optical transmission systems. There is clearly a need for a practical approach that supports the network provider’s planning and route design process for possible capacity upgrading in existing fibre plants, such as to retrofit 10 Gbit/s dense wave division multiplexing (DWDM) ...

We have measured the spin polarisation of electrons scattered superelastically from laser-excited Na atoms at a collision energy of 20 eV and a scattering angle of 30’. The measured spin polarisation is 0.095 zt0.048 for scattering from the 3p zPl/z excited state of Na. The polarisation changes sign if the laser is tuned to the 3p 2P3,z state, as is expected on formal grounds. We also present c...

We present preliminary polarisation VLBI maps of the gravitational lens system B0218+357, made at 3 different frequencies. 1. Summary We have made VLBI polarisation observations of the gravitational lens system Reduction of the data was made using standard procedures in the AIPS software package. Preliminary maps are presented in Figure 1. The " core " and " knot " components , seen by Patnaik ...

Abstract Individual and household based aggregate measures of worklessness can, and do, offer conflicting signals about labour market performance. We outline a means of quantifying the extent of any disparity, (polarisation), in the signals stemming from individual and household-based measures of worklessness and apply this index to data from 5 countries over 25 years. Built around a comparison...

We develop an analytic approach to calculation of the temperature and polarisation power spectra of the cosmic microwave background due to inflationary gravitational waves. This approach complements the more precise numerical results by providing insight into the physical origins of the features in the power spectra. We explore the use of analytic approximations for the gravitational-wave evolu...

The amino-acids which form the building blocks of biological proteins are all left-handed molecules. By contrast, when these molecules are made in the laboratory equal numbers of the right and left-handed versions are made. This homochirality found in biological material may well be a prerequisite for the origin of life and a number of processes have been proposed to produce the required enanti...

The study of the interaction of positrons with atoms and molecules has become increasingly popular, because more and more experimental activities have become feasible. Although exchange effects are absent, the polarisation effects, caused by the attractive nature between the positron and the target electrons, make the positron-molecule collisions more difficult to handle than the corresponding ...

We study by means of experiments and Monte Carlo simulations, the scattering of light in random media, to determine the distance upto which photons travel along almost undeviated paths within a scattering medium, and are therefore capable of casting a shadow of an opaque inclusion embedded within the medium. Such photons are isolated by polarisation discrimination wherein the plane of linear po...

Context. The high intensities and narrow bandwidths exhibited by some astronomical masers make them ideal tools for studying star-forming giant molecular clouds. The water maser transition JK−1K1 = 532−441 at 620.701 GHz can only be observed from above Earth’s strongly absorbing atmosphere; its emission has recently been detected from space. Aims. We sought to further characterize the star-form...