BACKGROUND To evaluate the impact and safety of different surgical techniques for aortic root replacement (ARR) on early and late morbidity and mortality in septuagenarians undergoing ARR. METHODS Ninety-five patients (73.8 +/- 3.2 years) were operated and divided into three groups according to the aortic root procedure; MECH-group (n = 51) patients with a mechanical composite graft, BIO-grou...

The contour method of residual stress measurement has recently been adapted to measure fractured, rather than cut specimens. The fracture contour method was capable of determining normal residual stresses acting prior to the planestrain failure of a large aluminium alloy forging, but shear residual stresses could not be measured (Prime et al., 2014, Eng. Fract. Mech., 116, 158-171). We demonstr...

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C. G. Johnson, J. M. N. T. Gray (2010), J. Fluid Mech., (Submitted) • “Weak, strong and detached oblique shocks in gravity driven granular free-surface žows”, J. M. N. T. Gray, X. Cui (2007), J. Fluid Mech., 579, 113–136 • “Dežecting dams and the formation of oblique shocks in snow avalanches at Flateyri, Iceland”, X. Cui, J. M. N. T. Gray, T. Johannesson (2007), J. Geophys. Res., 112, F04012 •...

This work is concerned with some extensions of the classical compressible Euler model of fluid dynamics in which the fluid internal energy is a measure-valued quantity. A first extension was derived from the hydrodynamic limit of a kinetic model involving a specific class of collision operators typical from quasi-linear plasma theory (see Eur. J. Mech. B Fluids 20 (2001) 303–327, and Contin. Me...

We trained two starlings (Sturnus vulgaris) to fly in a wind tunnel whilst wearing respirometry masks. We measured the metabolic power (P(met)) from the rates of oxygen consumption and carbon dioxide production and calculated the mechanical power (P(mech)) from two aerodynamic models using wingbeat kinematics measured by high-speed cinematography. P(met) increased from 10.4 to 14.9 W as flight ...

A non-traditional approach to the discretization of differential-geometrical connections was suggested by the authors in 1997. At the same time we started studying first order difference “black and white triangle operators (equations)” on triangulated surfaces with a black and white coloring of triangles. In this work, we develop the theory of these operators and equations, showing their simila...

We investigate the existence of quantum disentangled liquid (QDL) states in the half-filled Hubbard model on bipartite lattices. In the one dimensional case we employ a combination of integrability and strong coupling expansion methods to argue that there are indeed finite energy-density eigenstates that exhibit QDL behaviour in the sense of J. Stat. Mech. P10010 (2014). The states exhibiting t...

Observations of streamwise and crossflow instabilities on swept circular cylinders over a range of inclinations are presented. By considering sweep angles through the full range between the two extremes studied in the literature, we relate the streamwise vorticity of the unswept case (Kestin & Wood, J. Fluid Mech. 44) to the more aggressive crossflow instability at high sweep angles (Poll, J. F...