Performance and health of dairy calves fed limited amounts of acidified milk replacer

To compare growth performance of Brown Swiss calves fed acidified milk replacer (AMR) at 8% of birth weight, 20 newborn calves were reared under a new calf-feeding programme. Body weights, total weight gains and gains in body measurements, feed intake and feed efficiency values determined at different stages of growth of AMR-fed calves were comparable to those of calves fed sweet milk replacer (SMR). Faecal consistency scores and percent days with diarrhoea of calves offered AMR from four to 35 days of age were respectively 0.4 and 19.1% lower than those fed SMR. Most of the behavioural parameters studied were not unfavourably influenced by acidification of the replacer. In conclusion, growth, feed intake and feed efficiency characteristics of Brown Swiss calves fed AMR or SMR were not different from each other. However, incidence of diarrhoea of the young calves was decreased and health status of the calves was improved with the feeding of acidified milk. South African Journal of Animal Science Vol. 36(3) 2006: 149-15

Mesh update techniques for free-surface flow solvers using spectral element method

This paper presents a novel mesh-update technique for unsteady free-surface Newtonian flows using spectral element method and relying on the arbitrary Lagrangian--Eulerian kinematic description for moving the grid. Selected results showing compatibility of this mesh-update technique with spectral element method are given

A Schwarz lemma for K\"ahler affine metrics and the canonical potential of a proper convex cone

This is an account of some aspects of the geometry of K\"ahler affine metrics based on considering them as smooth metric measure spaces and applying the comparison geometry of Bakry-Emery Ricci tensors. Such techniques yield a version for K\"ahler affine metrics of Yau's Schwarz lemma for volume forms. By a theorem of Cheng and Yau there is a canonical K\"ahler affine Einstein metric on a proper convex domain, and the Schwarz lemma gives a direct proof of its uniqueness up to homothety. The potential for this metric is a function canonically associated to the cone, characterized by the property that its level sets are hyperbolic affine spheres foliating the cone. It is shown that for an $n$-dimensional cone a rescaling of the canonical potential is an $n$-normal barrier function in the sense of interior point methods for conic programming. It is explained also how to construct from the canonical potential Monge-Amp\`ere metrics of both Riemannian and Lorentzian signatures, and a mean curvature zero conical Lagrangian submanifold of the flat para-K\"ahler space.Comment: Minor corrections. References adde

Hamilton-Jacobi treatment of a non-relativistic particle on a curved space

In this paper a non-relativistic particle moving on a hypersurface in a curved space and the multidimensional rotator are investigated using the Hamilton-Jacobi formalism. The equivalence with the Dirac Hamiltonian formalism is demonstrated in both Cartesian and curvilinear coordinates. The energy spectrum of the multidimensional rotator is equal to that of a pure Laplace-Beltrami operator with no additional constant arising from the curvature of the sphere.Comment: 10 pages, LaTe

Strong strain path dependence of strain localizations and fracture in magnesium AZ31 sheet

This study compares the deformation and fracture behavior of a basal-textured Mg AZ31 alloy sheet under uniaxial tension and biaxial stretching by using an in-plane biaxial test setup capable of observing and measuring the deformation at both meso (millimeter) and microstructure scales. Strain distributions at the mesoscale and accompanying fracture surfaces indicate a significant dependence on strain path. At the microscale, limited slip activity in biaxial case promotes contraction twins, where severe strain localizations (epsilon(max)/epsilon(mean) approximate to 20) to the twins and their boundaries cause mainly transgranular fracture. This leads to a brittle, and a more pronounced shear-type fracture under biaxial stretching. In uniaxial case, considerable tensile twinning activity reorients the initial texture for slip activity. Strain localizations (epsilon(max)/epsilon(mean) approximate to 2) to the grain interiors and boundaries initiate mainly intergranular fracture. Samples fail by displaying both brittle and ductile fracture structures, with smaller shear lips compared to the biaxial case.Publisher's Versio

EPR study of Mn-implanted single crystal plates of TiO2 rutile

Single crystals of Mn-implanted TiO2 rutile have been investigated by electron paramagnetic resonance (EPR) technique at room temperature. We have observed an EPR signal on Mn4+ ions (S=frac(3, 2)) in the manganese-implanted single crystal TiO2 plates. Besides, weaker EPR signals due to Fe3+(S=frac(5, 2), L=0) and Cr3+(S=frac(3, 2)) ions have also been observed. Characteristic six-line splitting of the manganese EPR lines due to hyper-fine interaction with 55Mn nuclei (spin I=frac(5, 2)) has also been observed. Analysis of the EPR spectra shows that the manganese, iron and chromium ions substitute for Ti4+ ions in the TiO2 rutile host. Two structurally equivalent groups of the centers have been observed in the EPR spectra in correspondence with two octahedral positions of the Ti ions in the rutile structure. Spin Hamiltonian parameters for the crystal field of orthorhombic symmetry on the Mn4+, Fe3+ and Cr3+ centers have been obtained as result of computer modelling. © 2009 Elsevier B.V. All rights reserved

EPR study of Mn-implanted single crystal TiO2

Single crystals of manganese-implanted TiO2 rutile have been investigated by electron paramagnetic resonance (EPR) technique at room temperature. ESR spectra have been interpreted to correspond to the transitions among the spin multiplet (S=3/2) of the paramagnetic Mn4+ ion. Characteristic six-line hyper-fine splitting of the ESR spectra resulting from the spin I=5/2 of the Mn55 nucleus has been observed. Analysis of EPR spectra shows that manganese in TiO2 rutile host substitutes for Ti4+ ions. Two equivalent Mn4+ centers have been observed in the EPR spectra in correspondence with two equivalent octahedral positions of Ti ions in the rutile structure. Parameters of the crystal field of orthorhombic symmetry on the Mn4+ centers have been obtained as result of computer modelling. © 2009 IOP Publishing Ltd

Characterizing the universal rigidity of generic frameworks

A framework is a graph and a map from its vertices to E^d (for some d). A framework is universally rigid if any framework in any dimension with the same graph and edge lengths is a Euclidean image of it. We show that a generic universally rigid framework has a positive semi-definite stress matrix of maximal rank. Connelly showed that the existence of such a positive semi-definite stress matrix is sufficient for universal rigidity, so this provides a characterization of universal rigidity for generic frameworks. We also extend our argument to give a new result on the genericity of strict complementarity in semidefinite programming.Comment: 18 pages, v2: updates throughout; v3: published versio