The estimation of absolute and relative permeabilities for petroleum reservoirs on the basis of noisy data at wells is considered. The spatially varying absolute permeability is estimated by regularisation combined with a bi-cubic spline approximation. Relative permeability is represented by a given function of saturation with unknown coefficients. Numerical results provide an indication of the...

A piecewise rational cubic spline [5] has been used to visualize the positive data in its natural form. The spline representation is interpolatory and applicable to the scalar valued data. The shape parameters in the description of a rational cubic have been constrained in such a way that they preserve the shape of the positive data in the view of positive curve. As far as visual smoothness is ...

This work explores Kink soliton solution, periodic and rational function solutions for the fractional generalized anti-cubic (FGAC) nonlinearity in fiber Bragg gratings (BGs). The ((D_ζ^α G)/G)-expansion method is employed conjunction with idea of a conformable derivative. Due to its nature, solution looks have some restrictions.

In this paper we investigate Hesse’s elliptic curves Hμ : U + V 3 + W 3 = 3μUVW,μ ∈ Q − {1}, and construct their twists, Hμ,t over quadratic fields, and H̃(μ, t), μ, t ∈ Q over the Galois closures of cubic fields. We also show that Hμ is a twist of H̃(μ, t) over the related cubic field when the quadratic field is contained in the Galois closure of the cubic field. We utilize a cubic polynomial, R...

We define a so-called `-invariant for systems of homogeneous forms of the same degree, which coincides with the well known h-invariant for a single quadratic or cubic form, and bound the `-invariant of a system of rational forms F1, . . . , Fr in terms of the `-invariant of a single form α1F1 + . . . + αrFr in their complex pencil in case of algebraic α1, . . . , αr. As an application, we show ...

Two new oxides have been unambiguously identified as Bi2Tc2O7-delta with delta = 0.14(1) and Bi3TcO8 through X-ray absorption near-edge structure spectroscopy and neutron powder diffraction. The compound Bi2Tc2O7-delta has a cubic pyrochlore-type structure with a = 10.4746(1) A, space group Fd3m (origin choice 2), and Z = 8. The compound Bi3TcO8 is also cubic, a = 11.5749(1) A, space group P2(1...