1) La descarga del recurso depende de la página de origen
2) Para poder descargar el recurso, es necesario ser usuario registrado en Universia

Opción 1: Descargar recurso

Detalles del recurso


A theory for describing the elasticity of solids at simultaneous high pressures and high temperatures is developed by incorporating the fourth-order ahnarmonic theory of lattice dynamics into finite strain theory. The theory is applied to the analysis of a variety of data for MgO, SiO2 and NaCl, and the results for MgO and SiO2 used as the basis of a discussion of the constitution of the lower mantle. New results are reported of measurements of elastic properties of MgO shock-compressed to over 500 Kb.

The condition that finite strain equations be frame- indifferent is shown to require that only strain tensors belonging to a class of frame-indifferent strain tensors be used in finite strain expansion. It is shown that the generality of finite strain theory is not impaired by the inclusion of an explicit theory of thermal effects. Explicit equations for isotherms, isentropes and Hugoniots and for the effective elastic moduli of materials of cubic symmetry under hydrostatic stress are derived. The primary parameters of these equations are related to the elastic moduli and their pressure and temperature derivatives in an arbitrary reference state using thermodynamic identities, some of which are derived here.

Hugoniot data corresponding to different initial sample densities of MgO, SiO2 and NaCl and original ultrasonic data of NaCl are used to test both the compressional and thermal parts of the theory, and to refine the equations of state of these materials. The frame-indifferent analogue, E, of the usual "Eulerian" strain tensor, ε, is found to usually give faster convergence of finite strain expansions than the "Lagrangian" strain tensor, η. The effect of usinq differ­ent strain measures on the values of parameters derived from data is demonstrated, and the adverse effects of using inappropriately derived parameters in extrapolation equations is demonstrated. Thermal effects in Hugoniot data are reasonably well described, but higher-order anharmonic effects appear to be required in the theory in order to describe the high temperature ultrasonic and thermal expansion data.

Measured velocities of rarefaction waves propagating into shocked MgO are in accord with a two-stage longitudinal (elastic)-hydrodynamic (plastic) decompression model, and constrain the high-pressure elastic moduli of MgO.

The effects on the determination of the lower mantle constitution of temperature, varying composition, the presence of phases denser than oxides mixtures, and the presence of iron in the "low-spin" electronic state are estimated, and a trade-off between many of these factors demonstrated. Iron content could range between 6% and 15% by weight of FeO. Silica content could range from 33% to 50% or more by weight. Phases a few percent denser than oxides mixtures seem to be likely. The temperature is very indeterminable.

Pertenece a



Davies, Geoffrey Frederick - 

Id.: 70979748

Versión: 1.0

Estado: Final

Tipo:  application/pdf - 

Tipo de recurso: Thesis  -  NonPeerReviewed  - 

Tipo de Interactividad: Expositivo

Nivel de Interactividad: muy bajo

Audiencia: Estudiante  -  Profesor  -  Autor  - 

Estructura: Atomic

Coste: no

Copyright: sí

Formatos:  application/pdf - 

Requerimientos técnicos:  Browser: Any - 

Relación: [References] http://resolver.caltech.edu/CaltechTHESIS:02072018-154915291
[References] https://thesis.library.caltech.edu/10683/

Fecha de contribución: 09-feb-2018


* Davies, Geoffrey Frederick (1973) Elasticity of Solids at High Pressures and Temperatures : Theory, Measurement, and Geophysical Application. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechTHESIS:02072018-154915291

Otros recursos de la mismacolección

  1. Studies on Nuclear RNA

    The isolation of giant nuclear RNA (HnRNA) from rat ascites cells is described. By the criteria ...

  2. Characterization and Improvement of the Thermal Stability of TES Bolometers

    The successful detection and characterization of the B-modes in the Cosmic Microwave Background (...

  3. Functional Organization and Connections of the Middle Temporal Visual Area in the Macaque Monkey

    A variety of anatomical and physiological criteria have shown that the extrastriate visual cortex...

  4. Transition Metal Complexes of 1, 3-bis (2'-pyridylimino) Isoindolines and Their Use as Alcohol Oxidation Catalysts

    Condensation of 1, 2-dicyanobenzene and 2-amino-4-methylpyridine resulted in the formation of a l...

  5. General Methods for Analyzing Higgs Potentials

    This thesis is based on several papers published by the author and some more work to be published...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.