In classical Kirchhoff flow, an ideal incompressible fluid flows past an obstacle and around a motionless wake bounded by free streamlines. Since 1869 it has been known that in principle, the two-dimensional Kirchhoff flow over a polygonal obstacle can be determined by constructing a conformal map onto a polygon in the log-hodograph plane. In practice, however, this idea has rarely been put to ...

The first application of atomic absorption spectra to chemical analysis was made as long ago as 1860 by Gustav Robert Kirchhoff (1824-87), who demonstrated the presence of various elements in the solar atmosphere. Together with Robert Wilhelm Bunsen (181199), he showed shortly afterwards that atomic spectra, whether in emission or absorption, could be the basis of a powerful method of chemical ...

It has been shown recently that the use of two pairs of resistors with enhanced Johnson-noise and a Kirchhoff-loop—i.e., a Kirchhoff-Law-JohnsonNoise (KLJN) protocol—for secure key distribution leads to information theoretic security levels superior to those of a quantum key distribution, including a natural immunity against a man-in-the-middle attack. This issue is becoming particularly timely...

In this paper we obtain the constitutive equation for the second Piola-Kirchhoff stress tensor according to the linearized finite theory of elasticity for hyperelastic constrained materials. We show that in such a theory the three stress tensors (Cauchy stress tensor, first and second Piola-Kirchhoff stress tensor) differ by terms that are first order in the strain, while in classical linear th...

Current algorithms for imaging seismic reflection data can be subdivided into two classes: Kirchhoff (generalized Radon transform) and wave-equation (double-square-root and reverse-time) migration. Kirchhoff type methods rely on asymptotic and ray-geometrical considerations. Wave-equation imaging algorithms (one-way or twoway) appear to be more robust in the case of complicated velocity models ...

In this sequel to a rather recent paper on the classical problem of Helmholtz–Kirchhoff flows by Vic. V. Sychev, TsAGI Science Journal 41(5), 531–533 (2010), the representation of the flow far from the body and its specific implications discussed in that study are revisited. Here the concise derivation of these findings resorts to well-known Levi-Cività’s method and, alternatively, only fundame...

We consider a two phase elastic thin film with soft inclusions subject to bending dominated deformations. The (void) may comprise asymptotically small droplets within the matrix. perform dimension reduction analysis and obtain novel ‘Blake-Zisserman-Kirchhoff’ functional on natural space of ‘flat fractured’ two-dimensional isometric immersions that combines Kirchhoff's classical plate theory Bl...

Gaussian network model (GNM) is one of the most accurate and efficient methods for biomolecular flexibility analysis. However, the systematic generalization of the GNM has been elusive. We show that the GNM Kirchhoff matrix can be built from the ideal low-pass filter, which is a special case of a wide class of correlation functions underpinning the linear scaling flexibility-rigidity index (FRI...

In the usual formulation of the Kirchhoff diffraction integral, a scalar field with harmonic time dependence at frequency ω is deduced at the interior of a charge-free volume from knowledge of the field (or its normal derivative) on the bounding surface. In particular, the field is propagated forwards in time from the boundary to the desired observation point. Construct a time-reversed version ...

In a previous paper [1], the author and Shmel’tser started the construction of an extended Lyusternik–Shnirelman–Morse theory for the study of single-valued and multivalued functionals on the space Ω̂(M) of losed directed curves in a manifold M. The authors applied these methods to the classical problem (Kirchhoffs problem) about the free motion of a rigid body in an ideal incompressible liquid,...