African University of Science and Technology: Recent submissions

Now showing items 641-660 of 4790

  • Birational geometry of hypersurfaces in products of projective spaces 

    Ottem, John Christian (SpringerMathematische Zeitschrift, 2015)
    We study the birational properties of hypersurfaces in products of projective spaces. In the case of hypersurfaces in Pm x Pn, we describe their nef, movable and e ective cones and determine when they are Mori dream ...

  • Freezing colloidal suspensions: periodic ice lenses and compaction 

    Anderson, Anthony M; Worster, Michael Grae (CUP, 2014-10-14)
    Recent directional solidification experiments with aqueous suspensions of alumina particles (Anderson & Worster 2012) motivate a model for freezing colloidal suspensions that builds upon a theoretical framework developed ...

  • Modelling of partially-resolved oceanic symmetric instability 

    Bachman, Scott Daniel; Taylor, John Ryan (ElsevierOcean Modelling, 2014-08-04)
    A series of idealized numerical models have been developed to investigate the effects of partially resolved symmetric instability (SI) in oceanic general circulation models. An analysis of the energetics of symmetric instability ...

  • Noise generation by turbulence-propeller interaction in asymmetric flow 

    Robison, Rosalyn AV; Peake, Nigel (Cambridge University PressJournal of Fluid Mechanics, 2014)
    This paper is concerned with a particular source of both broadband and tonal aeroengine noise, termed Unsteady Distortion Noise (UDN). UDN arises from the interaction between turbulent eddies, which occur naturally in the ...

  • Zonally symmetric adjustment in the presence of artificial relaxation 

    Hitchcock, Adam Peter; Haynes, Peter Howard (American Meteorological SocietyJournal of the Atmospheric Sciences, 2014-06-15)
    Numerical experiments, presented in a companion paper, have been performed in which the zonal mean state of the stratosphere in a comprehensive, stratosphere-resolving, general circulation model is strongly relaxed (or ...


  • Astrophysical tests of modified gravity 

    Sakstein, Jeremy Aaron (University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, 2014-10-07)
    Einstein's theory of general relativity has been the accepted theory of gravity for nearly a century but how well have we really tested it? The laws of gravity have been probed in our solar system to extremely high precision ...

  • Stratified shear flow: experiments in an inclined duct 

    Meyer, Colin R; Linden, Paul Frederick (Journal of Fluid Mechanics, 2014-07-22)
    We present results of experiments on stratified shear flow in an inclined duct. The duct connects two reservoirs of fluid with different densities, and contains a counterflow with a dense layer flowing beneath a less-dense layer ...

  • The downward influence of stratospheric sudden warmings 

    Hitchcock, Adam Peter; Simpson, Isla R (Journal of the Atmospheric Sciences, 2014-07-14)
    The coupling between the stratosphere and the troposphere following two major stratospheric sudden warmings is studied in the Canadian Middle Atmosphere Model using a nudging technique by which the zonal mean evolution of ...

  • Entrainment in two coalescing axisymmetric turbulent plumes 

    Cenedese, Claudia; Linden, Paul Frederick (Journal of Fluid Mechanics, 2014-07-11)
    A model of the total volume flux and entrainment occurring in two coalescing axisym-metric turbulent plumes is developed and compared to laboratory experiments. The dynamical evolution of the two plumes is divided into three ...

  • The flow of rivers into lakes: Experiments and models 

    Hogg, Charles (University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, 2014-06-12)
    This study considers the motion of river water flowing into a lake. The study has two parts: field observations of an interflowing river in Lake Iseo (Italy); and laboratory experiments on basins fed by an underflow. In ...

  • Shear flow instabilities in viscoelastic fluids 

    Miller, Joel C. (University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, 2006-05-23)
    This dissertation is concerned with the theoretical study of the stability of viscoelastic shear flows. It is divided into two parts: part I studies inertialess coextrusion flows at large Weissenberg number where the ...


  • Solving Quasi-Variational Inequalities for Image Restoration with Adaptive Constraint Sets 

    Lenzen, F; Lellmann, Jan; Becker, F; Schnörr, C (SIAMSIAM Journal on Imaging Sciences, 2014-07-11)
    We consider a class of quasi-variational inequalities (QVIs) for adaptive image restoration, where the adaptivity is described via solution-dependent constraint sets. In previous work we studied both theoretical and numerical ...

  • The impact and rupture of a water-filled balloon on a rigid surface 

    Lund, Hugh Michael (University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, 2014-06-10)
    The dropping of a water-filled latex balloon onto a flat, rigid surface is an experiment that is known and has been performed by many, but on which there is no existing published work. High-speed images taken of the process ...

  • Quantum information, Bell inequalities and the no-signalling principle 

    Pitalúa-García, Damián (University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, 2014-02-04)
    This PhD thesis contains a general introduction and three main chapters. Chapter 2 investigates Bell inequalities that generalize the CHSH and Braunstein-Caves inequalities. Chapter 3 shows a derivation of an upper bound ...

  • Nonlinear and non-modal stability of structures evolving in shear flows 

    Daly, Conor Anthony (University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, 2014-04-08)
    This thesis explores a range of stability techniques applied to fluid structures that develop in various constant density flows. In particular, the stability of nonlinear structures which develop in rotating plane Couette ...

  • Dynamical instabilities in disc-planet interactions 

    Lin, Min-Kai (University of Cambridge, 2012-01-10)
    Protoplanetary discs can be dynamically unstable due to structure induced by an embedded giant planet. In this thesis, I discuss the stability of such systems and explore the consequence of instability on planetary ...

  • Pattern-forming in non-equilibrium quantum systems and geometrical models of matter 

    Franchetti, Guido (University of CambridgeDepartment of Applied Mathematics and Theoretical Physics, 2014-01-07)
    This thesis is divided in two parts. The first one is devoted to the dynamics of polariton condensates, with particular attention to their pattern-forming capabilities. In many configurations of physical interest, the ...

  • Designing a more nonlinearly stable laminar flow via boundary manipulation 

    Rabin, SME; Caulfield, Colm-cille Patrick; Kerswell, Richard Rodney (Cambridge University PressJournal of Fluid Mechanics, 2013-12-04)
    We show how a fully nonlinear variational method can be used to design a more nonlinearly stable laminar shear flow by quantifying the effect of manipulating the boundary conditions of the flow. Using the example of plane ...