Love waves in an inhomogeneous interstratum

Summary The propagation of Love waves in an inhomogeneous interstratum, whose rigidity and density follow generalized power law variation, lying between two homogeneous half-spaces has been considered. The characteristic frequency equations have been obtained. The computational results for some special cases are presented in the form of dispersion curves showing the variation of phase and group velocity of Love waves with wave number.     

Cosmological models in generalized scalar-tensor theory with cosmological term and bulk viscosity

Exponential and power law solutions for homogeneous cosmological modelshave been discussed in a generalized scalar-tensor theory where both thecosmological term and coupling parameter are taken tobe functions of the scalar field , along with the bulk viscousstress of the cosmic fluid. Assuming simple relationships of the scalarfield with the cosmological term and the coupling parameter, all thesolutions are studied in Dicke's revised units. By use of a conformaltransformation, the solutions are also expressed in atomic units.     

An anisotropic cosmological model in Brans-Dicke theory

Solutions of Brans-Dicke field equations are obtained when the source of the gravitational field is a perfect fluid with pressure equal to energy density and the metric is cylindrically symmetric of Marder-type. Various physical and geometrical properties of the model have been discussed. Finally the solutions have been transformed to the original form of Brans-Dicke (1961) theory and then through unit transformation to a general form.     

Some general results in self-creation cosmologies

Raychaudhuri-type equations are written for a cosmological model filled with perfect fluid and obeying the equations of a self-creation theory recently proposed by G. A. Barber. In addition some general results on spatially homogeneous cosmological models are obtained. The Hawking-Penrose energy condition suggests that the singularity can be avoided in this theory.     

Calculation of the second vertical derivative of gravity field

Summary Two formulas, using Taylor's series expansion method, have been developed by means of which the second vertical derivative of gravity field may be computed at any point in the horizontal plane of observation. A comparative study of the resolving powers of different approaches by performing numerical and filter response tests suggests that the formulas provide a definite improvement over many existing methods.NGRI Contribution No. 69-130.     

Some results in the general scalar tensor theory

Raychaudhuri-type equations are written for a cosmological model filled with a perfect fluid and obeying the equations of general scalar-tensor theory proposed by Nordtvedt. It is found that a non-rotating cosmological model may, in general, have a minimum volume. The Hawking-Penrose energy condition suggests that the singularity can be avoided in this theory.     

Development of an ensemble data assimilation system with LMDZ5 AGCM for regional reanalysis

Climate Dynamics - The present study describes a newly developed LMDZ–DART data assimilation system based on the Ensemble Kalman Filter (EnKF) with a stretched grid atmospheric model and...     

Some general results in modified Brans-Dicke cosmologies

Raychaudhuri-type equations are derived for cosmological models filled with a perfect fluid and obeying the Brans-Dicke equations with a cosmological term depending on the scalar field. In addition, some general results on spatially homogeneous cosmological models are obtained in the theories due to Bergmann and Wagoner and Uehara and Kim.     

Coefficient sets for one dimensional gravity operations using filter theory

Summary Between three at a time of the four quantities ellipticity of the niveau-ellipsoid of the earth, gravity flattening, gravity gradient flattening and ellipticity of the isogravitational surface touching the niveau-ellipsoid at the equator there are functional relations in form of determinant equations.

---

Zusammenfassung Zwischen jeweils drei der vier Grössen Abplattung des Niveauellipsoids der Erde, Schwereabplattung, Schweregradientabplattung und Abplattung der das Niveauellipsoid im Äquator berührenden Fläche konstanter Schwerebeschleunigung werden Funktionalbeziehungen in Form von Determinantengleichungen aufgestellt.

     

Apparent resistivity over a three layer earth with an inhomogeneous interstratum

Summary The theory of resistivity sounding on a three layer earth comprising an inhomogeneous interstratum has been presented. The electrical conductivity in the intermediate layer, embedded between two layers of uniform conductivity, is assumed to follow either generalised power law or exponential variation. A point source of current is placed on the surface. The electric potential functions on the ground surface have been obtained. The expressions for apparent resistivity over the above models for the Wenner and Schlumberger electrode configurations have been derived.