Applications of material coordinates in the soil and plant sciences.

1987 ◽  
Vol 35 (3) ◽  
pp. 361-370
Author(s):  
P.A.C. Raats
Keyword(s):  
Soil Water ◽  
Solid Phase ◽  
Continuum Theory ◽  
Central Problem ◽  
Plant Tissues ◽  
Common Basis ◽  
Plant Sciences ◽  
Theory Of Mixtures ◽  
The Common ◽  
The Continuum

The continuum theory of mixtures is used to show the common basis of models in three areas. In each, the central problem is the description of the deformation and motion of a reference continuum and of the movement of one or more constituents relative to this reference continuum. The three applications concern the movement of solutes relative to soil water, the movement of soil water relative to the solid phase of swelling/shrinking soils, and the movement of water, solutes, and gases relative to growing plant tissues. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Toward A Diffusing Continuum Theory of Composite Materials

1971 ◽  
Vol 38 (1) ◽  
pp. 8-14 ◽  
Author(s):  
A. Bedford ◽  
M. Stern
Keyword(s):  
Composite Materials ◽  
Dynamical Behavior ◽  
Continuum Theory ◽  
Relative Displacement ◽  
Classical Solutions ◽  
Longitudinal Wave Propagation ◽  
Theory Of Mixtures ◽  
The Individual ◽  
Laminated Materials ◽  
The Continuum

A theory of composite materials is proposed which is based on the continuum theory of mixtures. The constituents of a composite are modeled as superimposed continua which undergo individual deformations. Effects of structure on dynamical processes in composite materials are then simulated by specifying the coupling between the individual constituent motions. A novel feature of this model is the inclusion of diffusion with relative displacement coupling for perfectly bonded composites. A simple one-dimensional form of such a theory is presented, and, when compared with classical solutions for longitudinal wave propagation in laminated materials, predicts some aspects of the dynamical behavior extremely well.

Lubrication With Binary Mixtures: Liquid-Liquid Emulsion

1993 ◽  
Vol 115 (1) ◽  
pp. 46-55 ◽  
Author(s):  
A. Al-Sharif ◽  
K. Chamniprasart ◽  
K. R. Rajagopal ◽  
A. Z. Szeri
Keyword(s):  
Hydrodynamic Lubrication ◽  
Continuum Theory ◽  
Squeeze Film ◽  
Water Emulsion ◽  
Oil In Water ◽  
Squeeze Film Dampers ◽  
Liquid Emulsion ◽  
Theory Of Mixtures ◽  
Oil Water ◽  
The Continuum

There are numerous instances of technical importance in which multicomponent lubricants are utilized either by design or by necessity. In many of these cases one of the components is a liquid while the other component is a gas, as in squeeze film dampers during high frequency operation, or both components are liquids, as in the oil-water emulsion used in metal forming processes. In this paper our objective is to develop a self-consistent theory of hydrodynamic lubrication with bicomponent, liquid-liquid lubricants. The basic scientific method utilized is the continuum theory of mixtures. In this, first instance we test the model on journal bearings lubricated with water-in-oil and oil-in-water emulsions.

Lubricating Properties of Water in Oil Emulsions

2005 ◽  
Vol 128 (2) ◽  
pp. 296-311 ◽  
Author(s):  
James J. Benner ◽  
Farshid Sadeghi ◽  
Michael R. Hoeprich ◽  
Mark C. Frank
Keyword(s):  
Continuum Theory ◽  
Operating Conditions ◽  
Steel Ball ◽  
Lubricant Film Thickness ◽  
Lubricated Contacts ◽  
Steel Disc ◽  
Theory Of Mixtures ◽  
Oil Emulsions ◽  
The Continuum ◽  
Lubricating Properties

In this study the effect of water as a contaminant in lubricated contacts was analytically and experimentally investigated. A steel ball on glass disc apparatus was used to measure lubricant film thickness of pure oil and water in oil emulsions under various operating conditions. A steel ball on steel disc rig was used to measure friction as a function of various loads, slide to roll ratios and water in oil emulsions. A finite difference numerical model was developed using the continuum theory of mixtures and results were corroborated with the experimental measurements. Numerical results are in excellent agreement with the experimental results and indicate that water will flow around the contact. The experimental and analytical results suggest that for heavily loaded contacts water-in-oil emulsions perform essentially the same as pure oils.

Creep and recrystallization of large polycrystalline masses. I. General continuum theory

2006 ◽  
Vol 462 (2069) ◽  
pp. 1493-1514 ◽  
Author(s):  
Sérgio H Faria
Keyword(s):  
Continuum Theory ◽  
Transversely Isotropic ◽  
Current Approach ◽  
Symmetry Groups ◽  
Lattice Orientation ◽  
Balance Equations ◽  
Theory Of Mixtures ◽  
General Continuum ◽  
Continuous Diversity ◽  
The Continuum

This is the first of a series of works on the continuum mechanics and thermodynamics of creep and recrystallization of large polycrystalline masses. The general continuum theory presented here is suited to mono- and multi-mineral rocks. It encompasses several symmetry groups (e.g. orthotropic and transversely isotropic) and diverse crystal classes of triclinic, monoclinic and rhombic systems, among others. The cornerstone of the current approach is the theory of mixtures with continuous diversity, which allows one to regard the polycrystal as a ‘mixture of lattice orientations’. Following this picture, balance equations of mass, linear momentum, lattice spin, energy, dislocations, and entropy are set forth to describe the response of the polycrystal (i.e. the ‘mixture’), as well as of a group of crystallites sharing the same lattice orientation ( viz . a ‘species’). The connection between the balance equations for a species and those for the mixture is established by homogenization rules, formulated for every field of the theory.

A BOUNDARY VALUE PROBLEM IN GROUNDWATER MOTION ANALYSIS — COMPARISON OF PREDICTIONS BASED ON DARCY’S LAW AND THE CONTINUUM THEORY OF MIXTURES

1993 ◽  
Vol 03 (02) ◽  
pp. 231-248 ◽  
Author(s):  
D. MUNAF ◽  
A.S. WINEMAN ◽  
K.R. RAJAGOPAL ◽  
D.W. LEE
Keyword(s):  
Radial Flow ◽  
Darcy’S Law ◽  
Classical Problem ◽  
Mixture Theory ◽  
Continuum Theory ◽  
Darcy's Law ◽  
Low Flow ◽  
Theory Of Mixtures ◽  
Equations Of Motions ◽  
The Continuum

The classical problem of the radial flow to a well in a confined horizontal aquifer is solved using two theories: (1) when the flow is based on Darcy’s law, and (2) when the flow is based on equations of the Continuum Theory of Mixtures. The latter reduce to Darcy’s law when the inertia of the fluid can be neglected, and when the viscosity of the fluid does not enter into the expression for the partial stress for the fluid. A comparison of the two solutions shows that there are conditions when Mixture Theory could predict results that provide a significant departure from those predicted by Darcy’s Law. In this paper we delineate the extent of validity of Darcy’s law, within the context of a more general theoretical framework. The results of our work indicate that Darcy’s law is indeed quite good for low flow rates for a fluid like water. However this is not the case for dense fluids, say oils or effluents, due to the inclusion of inertial effects in the equations of motions.

A Continuum Theory of Fluid Saturated Porous Media

1971 ◽  
Vol 38 (1) ◽  
pp. 1-7 ◽  
Author(s):  
A. Bedford ◽  
J. D. Ingram
Keyword(s):  
Constitutive Relations ◽  
Deformation Gradient ◽  
Continuum Theory ◽  
Elastic Solid ◽  
Entropy Inequality ◽  
Heat Conducting ◽  
Saturated Porous Media ◽  
Theory Of Mixtures ◽  
Biot Equations ◽  
The Continuum

A continuum theory, for a heat-conducting, porous elastic solid saturated by a mixture of heat-conducting, viscous compressible fluids, is developed using the continuum theory of mixtures. Gradients of the fluid densities and the second deformation gradient of the solid constituent are included among the independent constitutive variables as proposed by Mu¨ller [17]. The Clausius-Duhem entropy inequality and the principle of material indifference are used to obtain rational constitutive relations for the medium. Linear constitutive equations are presented, and a theory equivalent to a generalization of the Biot equations is obtained.

Increasing adolescent girls’ social competence through cognitive counseling by social workers

2021 ◽  
pp. 146801732110102
Author(s):  
Chau-kiu Cheung
Keyword(s):  
Social Competence ◽  
Social Workers ◽  
Adolescent Girls ◽  
Cognitive Theory ◽  
Daily Life ◽  
Young Female ◽  
Common Basis ◽  
The Social ◽  
The Common ◽  
Lower Education

Summary Despite the common basis of cognitive theory for cognitive counseling and social competence development, no research has charted the effectiveness of the counseling in raising social competence in young female residents of the residential service. To examine the effectiveness, this study analyzed data gleaned from monthly surveys of young female residents and their social workers regarding the latter’s daily life cognitive counseling. The data consisted of 391 cases pairing the female residents and social workers in Hong Kong over 33 months. Findings The cases afforded a cross-lagged analysis showing the raising of the girl’s social competence by the worker’s cognitive counseling earlier in the previous month. In substantiating this raising, the analysis also indicated that earlier social competence did not affect the counseling. Applications The findings imply the worth of promoting the social worker’s daily life cognitive counseling to advance girl residents’ social competence. Such counseling is particularly helpful to girls with lower education, who are lower in social competence.

The Common Denominator of Land Classification in Canada: an Ecological Approach to Mapping

1980 ◽  
Vol 56 (1) ◽  
pp. 19-20 ◽  
Author(s):  
J. S. Rowe
Keyword(s):  
Ecological Approach ◽  
Common Denominator ◽  
Land Classification ◽  
Ecological Land Classification ◽  
Common Basis ◽  
The Common

The cores and boundaries of land units are located by reference to relationships between climate, landform and biota in ecological land classification. This appeal to relationships, rather than to climate, or to geomorphology, or to soils, or to vegetation alone, provides the common basis for land classification.

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