Using a full-potential ab-initio technique I study the electronic and magnetic properties of the (001) surfaces of the half-Heusler alloys, NiMnSb, CoMnSb and PtMnSb and of the full-Heusler alloys Co 2 MnGe, Co 2 MnSi and Co 2 CrAl. The MnSb terminated surfaces of the half-Heusler compounds present properties similar to the bulk compounds and, although the half-metallicity is lost, an important...

Butterflies of the genus Papilio have polarisation-sensitive photoreceptors in all regions of the eye, and different spectral types of receptor are sensitive to different e-vector orientations. We have studied the consequences of this eye design for colour vision in behavioural tests and find that Papilio spp. see false colours due to the polarisation of light. They discriminate between vertica...

Polarised stereoscopic projection involves the polarisation of the two projected images in orthogonal directions e.g. +/45 degrees for linear polarisation, or clockwise and counter-clockwise for circular polarisation. When LCD projectors are used for polarised stereoscopic projection it is important to take into consideration the fact that the output of these types of projectors is already pola...

Model polarisation potentials for use in calculating positron-molecule cross sections are often based on approximations in which terms that depend on the sign of the charge of the projectile are neglected. Thus, these potentials do not fully distinguish between electron and positron scattering. The validity of using such potentials for positronH2 collisions is investigated by performing scatter...

We have analysed the angular power spectra of the Parkes radio continuum and polarisation survey of the Southern galactic plane at 2.4 GHz. We have found that in the multipole range l = 40–250 the angular power spectrum of the polarised intensity is well described by a power-law spectrum with fitted spectral index αL = 2.37 ± 0.21. In the same multipole range the angular power spectra of the E ...

grading of agricultural products has always been a subject of research by scientists. one of the criteria to be chosen for grading of fruits is the fruit's level of ripeness. different methods have been employed to assess the status of fruit ripeness some of which are destructive and others are not so. in this research, a noninvasive capacitive method was used to estimate the ripeness leve...

some issues; leakage, tunneling currents, boron diffusion are threatening sio2 to be used as a good gate dielectric for the future of the cmos (complementary metal- oxide- semiconductor) transistors. for finding an alternative and novel gate dielectric, the nio (nickel oxide) and pva (polyvinyl alcohol) nano powders were synthesized with the sol-gel method and their nano structural properties w...

We report a study in which Andreev reflection using a Nb point contact is used to measure the transport spin polarisation of the 4d itinerant ferromagnet SrRuO3. By performing the study in high quality thin films with residual resistivities less than 7μΩ-cm, we ensure that the study is done in the ballistic limit, a regime which is difficult to reach in oxide ferromagnets. The degree of transpo...

Planar polarity describes the coordinated polarisation of cells or structures in the plane of a tissue. The patterning mechanisms that underlie planar polarity are well characterised in Drosophila, where many events are regulated by two pathways: the 'core' planar polarity complex and the Fat/Dachsous system. Components of both pathways also function in vertebrates and are implicated in diverse...

We propose a new method for dynamic nuclear polarisation in a quasi one-dimensional quantum wire utilising the spin-orbit interaction, the hyperfine interaction, and a finite sourcedrain potential difference. In contrast with current methods, our scheme does not rely on external magnetic or optical sources which makes independent control of closely placed devices much more feasible. Using this ...