New generalized dispersion relation for low-frequency electromagnetic waves in Hall-magnetohydrodynamic dusty plasma

A generalized linear theory for electromagnetic waves in a homogeneous dusty magnetoplasma is presented. The waves described are characterized by a frequency which is much smaller (larger) than the electron gyrofrequency (dust plasma and dust gyrofrequencies), and a long wavelength (in comparison with the ion gyroradius and the electron skin depth). The generalized Hall- magnetohydrodynamic (GH-MHD) equations are derived by assuming massive charged dust macroparticles to be immobile, and Fourier transformed to obtain a general dispersion relation. The latter is analyzed to understand the influence of immobile charged dust grains on various electromagnetic wave modes in a magnetized dusty plasma.

Dynamics of a dust crystal with positive and negative dust

A dust crystal consisting of charged dust grains of alternating charge sign (.../+/-/+/-/+/...) and mass is considered. Considering the equations of longitudinal motion, a linear dispersion relation is derived from first principles, and then analyzed. Two modes are obtained, including an acoustic mode and an inverse-dispersive optic-like one. The nonlinear aspects of longitudinal dust grain motion are also briefly addressed, via a Boussineq and Korteweg- de Vries description.

Postbuckling Behaviour of Hat Stiffened Thin Skinned Carbon Fibre Composite Panels

The results of a combined experimental and numerical study of hat-stiffened co-cured carbon-fibre composite panels loaded in uniaxial compression are presented. All panels consisted of two integrated stiffeners separated by an eight-ply thick skin bay of lay-up [*45/0190], . The effects of a 100 mm circular cutout in the skin was also investigated. The ultimate strength of all panels was governed by the load carrying capacity of the stiffeners. A change in the skin's buckling mode-shape was also observed for all panels loaded deep in the postbuckling region. The strains induced at the interior free-edge were not found to be critical. Non-linear finite element results correlated well with the prebuckling and initial postbuckling strain and displacements results obtained by experiment.

Man-up Against Suicide

Male suicide rates are high in Western countries including the US and Canada. Underpinned by men’s resistance to health help-seeking and challenges diagnosing mental illness including male depression, suicide ends the lives of many men amid inflicting pain and grief on the family and friends who are left behind. Fuelled by the discordant relationship between men’s low rates of depression and high rates of suicide we embarked on a unique and novel photovoice study title Man-Up Against Suicide. Specifically, men who have contemplated suicide in the past, and individuals (men and women) who have lost a male partner, family member or friend to suicide were invited to take photographs representing their experiences with men’s suicide with the ultimate goal of messaging ‘at risk’ men that there are alternatives to taking one’s life. Participants subsequently completed semi-structured individual interviews narrating the photographs and providing captions to accompany their selected images. In this presentation we share the preliminary study findings along with some participant photographs and narratives as a means to discussing; 1) men’s experiences of suicidal behaviours and their management strategies; and, 2) how men’s and women’s experiences of losing a male to suicide can de-stigmatize men’s mental illness and raise public awareness about male suicide.