Beyond supply and demand: addressing the complexities of workforce exclusion in Australia

Workforce exclusion is a complex and enduring problem in Australia, with some groups of job seekers more likely to be disadvantaged in the labour market than others. We identify a dominant unemployment narrative of ‘work first’ that surrounds unemployment interventions, and ignores the nature of disadvantage and its relationship to workforce exclusion, and reduces unemployment to a simple matter of labour market supply and demand. This approach privileges immediate economic productivity and exit from welfare payments over sustainable attachment to quality jobs. We examine fourteen programs for disadvantaged job seekers under one national provider network. Data was gathered from eleven semi-structured telephone interviews and eight evaluation reports and analysed using thematic analysis supported by NVivo. Our findings challenge the dominant narrative and argue that both ends of the supply and demand equation need to be examined, stressing the importance of a partnership-orientated and capacity building focus on the unemployed person, and the significance of quality employment with long term support. We identify the importance of acknowledging job seekers’ strengths, aspirations and preferences, and of job seekers having agency to determine their own pathways with support from service providers

Kinetic Electron and Ion Instability of the Lunar Wake Simulated at Physical Mass Ratio

The solar wind wake behind the moon is studied with 1D electrostatic particle-in-cell (PIC) simulations using a physical ion to electron mass ratio (unlike prior investigations); the simulations also apply more generally to supersonic flow of dense magnetized plasma past non-magnetic objects. A hybrid electrostatic Boltzmann electron treatment is first used to investigate the ion stability in the absence of kinetic electron effects, showing that the ions are two-stream unstable for downstream wake distances (in lunar radii) greater than about three times the solar wind Mach number. Simulations with PIC electrons are then used to show that kinetic electron effects can lead to disruption of the ion beams at least three times closer to the moon than in the hybrid simulations. This disruption occurs as the result of a novel wake phenomenon: the non-linear growth of electron holes spawned from a narrow dimple in the electron velocity distribution. Most of the holes arising from the dimple are small and quickly leave the wake, approximately following the unperturbed electron phase-space trajectories, but some holes originating near the center of the wake remain and grow large enough to trigger disruption of the ion beams. Non-linear kinetic-electron effects are therefore essential to a comprehensive understanding of the 1D electrostatic stability of such wakes, and possible observational signatures in ARTEMIS data from the lunar wake are discussed.Comment: 9 pages, 10 figure

Non-linear collisionless plasma wakes of small particles

The wake behind a spherical particle smaller than the Debye length ( De) in owing plasma is calculated using a particle-in-cell code. The results with di erent magnitudes of charge reveal substantial non-linear e ects down to values that for a oating particle would correspond to a particle radius approximately 102 De. The peak potential in the oscillatory wake structure is strongly suppressed by non-linearity, never exceeding approximately 0:4 times the unperturbed ion energy. By contrast, the density peak arising from ion focusing can be many times the ambient. Strong heating of the ions occurs in the non-linear regime. Direct ion absorption by the particle is not important for the far wake unless the radius exceeds 101 De, and is therefore never signi cant (for the far wake) in the linear regime. Reasonable agreement with full-scale linear-response calculations are obtained in the linear regime. The wake wavelength is con rmed and an explanation, in terms of the conical potential structure, is proposed for experimentally- observed oblique alignment of di erent-sized grains

Forces on a small grain in the nonlinear plasma wake of another

The transverse force on a spherical charged grain lying in the plasma wake of another grain is analyzed to assess the importance of ion-drag perturbation, in addition to the wake-potential-gradient. The ion-drag perturbation is intrinsically one order smaller than the wake-potential force in the ratio of grain size (rp) to Debye length (lambdaDe). So ion-drag perturbation is important only in nonlinear wakes. Rigorous particle-in-cell calculations of the force are performed in the nonlinear regime with two interacting grains. It is found that even for quite large grains, rp/lambdaDe=0.1, the force is dominated by the wake-potential gradient. The wake-potential structure can then help explain the preferred alignment of floating dust grains.National Science Foundation (U.S.) (NSF/DOE Grant DE-FG02-06ER54982

Kinematic Mechanism of Plasma Electron Hole Transverse Instability

It is shown through multidimensional particle-in-cell simulations that at least in Maxwellian background plasmas the long-wavelength transverse instability of plasma electron holes is caused not by the previously proposed focusing of trapped particles but instead by kinematic jetting of marginally passing electrons. The mechanism is explained and heuristic analytic estimates obtained which agree with the growth rates and transverse wave numbers observed in the simulations.United States. National Aeronautics and Space Administration (Grant NNX16AG82G

Particle in cell calculation of plasma force on a small grain in a non-uniform collisional sheath

The plasma force on grains of specified charge and height in a collisional DC plasma sheath is calculated using the multidimensional particle in cell code COPTIC. The background ion velocity distribution functions for the unperturbed sheath vary substantially with collisionality. The grain force is found to agree quite well with a combination of background electric-field force plus ion drag force. However, the drag force must take account of the non-Maxwellian (and spatially varying) ion distribution function, and the collisional drag enhancement. It is shown how to translate the dimensionless results into practical equilibrium including other forces such as gravity.United States. Dept. of Energy (National Science Foundation (U.S.). Grant DE-FG02-06ER54982