Supporting postgraduate students in their efforts to soar through the rings is a crucial endeavour of contemporary universities. A variation on this approach is ringing the changes for such students – that is, identifying the distinct stages in their learning journeys and seeking ways to maximise opportunities to facilitate their movement through each stage and in the transition from one stage ...

4. Series of lectures on statistical turbulence written for amateurs but not experts. Elementary aspects and problems of turbulence in two and three dimensional Navier-Stokes equation are introduced. A few properties of scalar turbulence and transport phenomena in turbulent flows are described. Kraichnan’s model of passive advection is discussed a bit more precisely. Part 1: Approaching turbule...

Direct numerical simulations are used to compare turbulent diffusivities of heat and salt during the growth and collapse of Kelvin–Helmholtz billows. The ratio of diffusivities is obtained as a function of buoyancy Reynolds number Reb and of the density ratio R (the ratio of the contributions of heat and salt to the density stratification). The diffusivity ratio is generally less than unity (he...

The gene for polysyndactyly (Ps) arose during a neutron irradiation experiment at the M.R.C. Radiobiological Unit at Harwell (Batchelor, Phillips & Searle, 1966), and was offered to the author in November 1964. The mice from Harwell were outcrossed to CB $? (the Fx of CBA/Gr &?xC57 BL/Gr $?). The stock was outcrossed again in late 1966 to improve fertility. Rigorous brother/sister mating has no...

The theory of supermanifolds, first proposed by Salam and Strathdee [15] as a geometrical framework for understanding the supersymmetry, is now well understood mathematically and can be formulated in roughly two different ways: either by defining a notion of superdifferential structure with ”supernumbers” which generalizes the differential structure of R and by gluing together these local model...

The mixing of substances is present in various turbulent systems. Examples arise in reacting flows and combustion, mixing of salt and plankton in oceans and of chemical pollutants in the stratosphere [1]. The physics of scalar mixing depends strongly on the ratio of the kinematic viscosity ν of the fluid to the diffusivity κ of the scalar. It is given by the Schmidt number Sc = ν/κ. For the fol...

Genomic sequencing projects are beginning to reveal regions of extensive DNA homology between bacterial genera. Public fears of the spread of genetically modified organisms into the food chain and the increasing prevalence of multi-drug resistant disease in humans highlight the implications of horizontal gene transfer. The striking DNA sequence similarity between the two uniquely identified tet...

The spread of an alien invasive grass (gamba grass—Andropogon gayanus) in the tropical savannas of Northern Australia is a major threat to habitat quality and biodiversity in the region, primarily through its influence on fire intensity. Effective control and eradication of this invader requires better insight into its spatial distribution and rate of spread to inform management actions. We use...

The present work considers the turbulent air flow inside an annular high speed rotor-stator cavity opened to the atmosphere at the periphery. The interdisk-spacing is sufficiently large so that the boundary layers developed on each disk are separated and the flow belongs to the regime IV of Daily and Nece (1960). In such a system, the solid body rotation of the core predicted by Batchelor in ca...

-The effect of elevated pressure on the stability of the homogeneous bubbly flow regime in a gas-liquid bubble column is examined. Experiments were performed in a 0.15 m diameter bubble column operated at pressures in the range 0.1-1.3 MPa with nitrogen as the gas phase and water as the liquid phase. The transition from homogeneous to heterogeneous flow regime was determined by two procedures. ...