We have investigated analytically the asymptotic behavior of the reflected high-order modes induced by the presence of the so-called DtN2 absorbing boundary condition when employed for solving exterior Helmholtz problems with

prolate spheroid shaped scatterers.

The axis lengths of a

prolate spheroid can be estimated from its maximum area if a ratio of the minor axis to the major axis is assumed.

On the basis of visual inspection, available photographs, or general familiarity with an organism, each species was sorted into one of three general categories of overall body geometry: the sphere (L = D), the

prolate spheroid (D [is less than] L [is less than or equal to] 3D; more or less terete cross section), and the cylinder (L [is greater than] 3D; terete or nonterete cross-sectional geometry).

The downside with the

prolate spheroids is that percolation will occur for smaller volume fraction than spheroid particles.

In our study we approximate these particles by

prolate spheroids.

If, however, the body of a

prolate spheroid has a region of higher density in the rear half of the body, as postulated in the gravity-buoyancy model, G is located posterior to B and H (Fig.

15], we have further expanded our studies to Stokes flow problems around nonconvex bodies, such as the inverted

prolate spheroids.

Since one semiaxis can be recovered from central section, we condition on the knowledge of its length and we are interested in the other semiaxis length, that is, A for

prolate spheroids, C for oblate spheroids and D for profiles.

It is worth noting that diffraction and scattering by

prolate spheroids are of continuous interest.

For

prolate spheroids where b > a, [chi] is larger than 2, and for oblate spheroids where b < a, x is less than 2.

Deleuil, "Multiple scattering of electromagnetic waves from two

prolate spheroids with perpendicular axes of revolution," Radio Science, Vol.

In fact, the parameter x equals 2 for a sphere, but for

prolate spheroids where b > a ([[xi].