Paid work associated with digital platform businesses (in taxi, delivery, maintenance and other functions) embodies features which complicate the application of traditional labour regulations and employment standards. This article reviews the extent of this type of work in Australia, and its main characteristics. It then considers the applicability of existing employment regulations to these ‘gig’ jobs, citing both Australian and international legislation and case law. There is considerable uncertainty regarding the scope of traditional regulations, minimum standards and remedies in the realm of irregular digitally mediated work. Regulators and policymakers should consider how to strengthen and expand the regulatory framework governing gig work. The article notes five major options in this regard: enforcement of existing laws; clarifying or expanding definitions of ‘employment’; creating a new category of ‘independent worker’; creating rights for ‘workers’, not employees; and reconsidering the concept of an ‘employer’. We review the pros and cons of these approaches and urge regulators to be creative and ambitious in better protecting the minimum standards and conditions of workers in these situations.

We present high-resolution Compton scattering spectra from Li single crystals together with corresponding highly accurate local-density-approximation (LDA) based computations.The data are analyzed to obtain Fermi surface radii along the three principal symmetry directions; the maximum measured anisotropy is found to be (4.6~1.0)%. Comparisons between the measured and computed spectra clearly reveal departures from the conventional one-particle LDA picture of the ground state momentum density of the electron gas. This study establishes the potential of Compton scattering as a tool for investigating Fermiology-related issues in materials. PACS numbers: 61.80.Ed, 41.60.Ap, 71.25.Hc, 71.45.Gm It is well known that in a Compton scattering experiment one measures the momentum distribution [1](2) J(p~) = n(p) dp~dpy,where n(p) is the ground state electron momentum density, 2 n(p) = g W;(r) exp(ip . r) dr in terms of the electron wave functions 'Ir;(r). The summation in (2) extends over all occupied states. Therefore, the Compton profile J(p, ) contains fingerprints of Fermi surface (FS) breaks in the underlying 3D momentum distribution n(p). The size of the FS discontinuity in the momentum density and its possible renormalization due to electron-electron correlations is a fundamental property of the ground state electronic structure, inaccessible to other k-resolved spectroscopies such as angle-resolved photoemission, the de Haasevan Alphen effect (dHvA), and positron annihilation [2]. This unique capability of the Compton technique for exploring Fermiology-related issues has, however, been difficult to exploit to date because the momentum resolution available using y-ray sources is not adequate for this purpose. The advent of high intensity, high energy, well polarized synchrotron sources removes this limitation and offers new opportunities for developing Compton scattering as a tool for investigating spectral properties of the electron gas at and near the Fermi energy in wide classes of materials [3].With this motivation, we present in this Letter a highresolution synchrotron-based Compton study of Li single crystals [4], and identify, for the first time, Fermi surface signatures in the data. The presence of a 2D integral in Eq. (1) implies that the structure associated with FS cross-ings will generally be more apparent in the derivatives of J(p, ), rather than J(p, ) itself. Accordingly, parallel highly accurate computations of the Compton profiles (CP's) within the band theory framework are reported; we are not aware of a previous calculation of CP's in the literature where the line shape in the derivative spectra has been properly computed. Comparisons between the measured and computed Compton spectra clearly reveal departures from the simple one-particle local-densityapproximation (LDA) based picture of the momentum density.It is noteworthy that the Compton experiment essentially measures a ground state property of the electron gas [5] in contrast with techniques such as dHvA and angle-resolved photoemission. Als...

Angular correlation of annihilation radiation (ACAR) from silica-powder pellets and silica aerogel has been measured in order to investigate the slowing down of free positronium (Ps) atoms by collisions with silica grains and gas molecules. The data for the pellets and the aerogel in vacuum show that the slowing down of parapositronium (p-Ps) in the free space between the silica grains depends on the number of collisions and hence on the mean distance between the grains. The momentum distribution of orthopositronium (o-Ps) shows further slowing down because of its long lifetime. From the ACAR data obtained from specimens of aerogel 611ed with gases (He, Ne, Ar, Kr, Xe, H2, CH4, CO2, and iso-C4Hqo), the momentum-transfer cross sections between Ps and the gas molecules are estimated. It is concluded that the Ps kinetic energy is transferred only to the translational motion of the gas molecules, i.e. , the excitations of vibration and rotation of the molecules are negligible. PACS number(s): 36.10.Dr, 34.50. -s, 78.70.Bj I. INTR. ODU CTIONIt was observed in the mid 1960s that the angular correlation of annihilation radiation (ACAR) and positron lifetime spectra in metal oxide and metal Huoride powders [1,2] showed formation of positronium (Ps). In 1968, Paulin and Ambrosino [3] reported that the Ps component in the positron lifetime spectra for silica powders depends on the grain diameter. It was postulated that the Ps atoms form inside the grains and then disuse out of them [4]. Paulin and Ambrosino also observed the eA'ect of air on the o-Ps annihilation. Following this, silica powders were used for investigating the interactions between Ps and paramagnetic gases [5 -8].

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