Representations of solutions of the wave equation based on relativistic wavelets

A representation of solutions of the wave equation with two spatial coordinates in terms of localized elementary ones is presented. Elementary solutions are constructed from four solutions with the help of transformations of the affine Poincar\'e group, i.e., with the help of translations, dilations in space and time and Lorentz transformations. The representation can be interpreted in terms of the initial-boundary value problem for the wave equation in a half-plane. It gives the solution as an integral representation of two types of solutions: propagating localized solutions running away from the boundary under different angles and packet-like surface waves running along the boundary and exponentially decreasing away from the boundary. Properties of elementary solutions are discussed. A numerical investigation of coefficients of the decomposition is carried out. An example of the field created by sources moving along a line with different speeds is considered, and the dependence of coefficients on speeds of sources is discussed.Comment: submitted to J. Phys. A: Math. Theor., 20 pages, 6 figure

Impact of Optimized Breastfeeding on the Costs of Necrotizing Enterocolitis in Extremely Low Birthweight Infants

To estimate risk of NEC for ELBW infants as a function of preterm formula and maternal milk (MM) intake and calculate the impact of suboptimal feeding on NEC incidence and costs

Bidimensional sodium ionic conduction of oxyborates Na(2)M(2)(BO(3))(2)O (M = Al, Ga) and Na(2-2x)Ca(x)Ga(2)(BO(3))(2)O (x=0.25, 0.50)

Crystalline samples of Na2M2(BO3)2O (M = Al, Ga), Na1.5Ca0.25Ga2(BO3)2O and NaCa0.5Ga2(BO3)2O are prepared by conventional high temperature solid state synthesis technique. Temperature dependent impedance spectroscopy measurements are performed. For Na2Al2(BO3)2O and Na2Ga2(BO3)2O, high and low temperature regimes have to be distinguished. Only one regime is observed for the calcium-substituted samples Na1.5Ca0.25Ga2(BO3)2O and NaCa0.5Ga2(BO3)2O

Critical behaviour of the electrical resistivity in amorphous ferromagnetic alloys

Electrical resistivity ρ of the amorphous FexNi80-xB19Si1 (χ = 10, 13, 16), Fe20Ni60B20 and Fe20Ni60P14B6 alloys has been measured in a wide temperature range which embraces the second-order magnetic phase transition at the Curie point TC. Analysis of the data reveals that in these systems critical region has a much wider range compared with that in crystalline ferromagnets even though dρ/dT for T≥TC decreases at a rate that is comparable in both the cases. For the glassy ribbons coming from the same alloy batch, TC and the specific heat critical exponent a have the same values as those determined from our previous magnetic measurements. a for all the investigated alloys possesses values that are typical of a Heisenberg ferromagnet

3D Reconstruction of Cochlea Geometries Using Human microCT Images

Understanding of the pathophysiology of hearing process and its connection with pathologic conditions which are linked with hearing loss requires an accurate description of the inner ear geometry. In this study, a semi-automated methodology for three-dimensional (3D) reconstruction of the main inner ear structures: i) scalae, ii) basilar membrane, iii) vestibule, iv) stapes and v) round window is proposed. The methodology is based on the acquisition of microCT images and the employment of appropriate image processing techniques for accurate and semi-automated reconstruction. The Level Set algorithm employed with marching cubes algorithm is the main component of the methodology. The proposed methodology outcome is a 3D representation of the inner ear structures in a geometry format which can be used for further processing for inner ear modeling