Using a framework for variations of classroom inquiry (National Research Council [NRC], 2000, p. 29), this study explored 40 inservice elementary teachers' planning, modification, and enactment of kit-based science curriculum materials. As part of the study, a new observation protocol was modified from an existing protocol (Practices of Science Observation Protocol [P-SOP]) to measure the amount of teacher direction in science inquiry lessons (Practices of Science Observation Protocol + Directedness [P-SOPd]). An embedded mixed methods design was employed to investigate four questions: 1. How valid and reliable is the P-SOPd? 2. In what ways do inservice elementary teachers adapt existing elementary science curriculum materials across the inquiry continuum? 3. What is the relationship between the overall quality of inquiry and variations of inquiry in elementary teachers' enacted science instruction? 4. How do inservice elementary teachers' ideas about the inquiry continuum influence their adaptation of elementary science curriculum materials? Each teacher chose three lessons from a science unit for video-recorded observation, and submitted lesson plans for the three lessons. Lesson plans and videos were scored using the P-SOPd. The scores were also compared between the two protocols to determine if a correlation existed between the level of inquiry (measured on the P-SOP) and the amount of teacher direction (measured on the P-SOPd). Findings indicated no significant differences between planned and enacted lessons for the amount of teacher direction, but a correlation existed between the level of inquiry and the amount of teacher direction. In effect, the elementary teachers taught their science curriculum materials with a high level of fidelity for both the features of inquiry and the amount of teacher direction. A smaller group of three case study teachers were followed for the school year to give a more in-depth explanation of the quantitative findings. Case study findings revealed that the teachers' science instruction was teacher-directed while their conceptions of inquiry were student-directed. This study contributes to existing research on preservice teachers' learning about the continuum (Biggers & Forbes, 2012) and inservice teachers' ideas about the five features of inquiry (Biggers & Forbes, in press).

The principal contribution of this dissertation is a theory of Strongly Orthotropic Continuum Mechanics that is derived entirely from an assertion of geometric strain indeterminacy. Implementable into the finite element method, it can resolve widespread kinematic misrepresentations and offer unique and purportedly exact strain-induced energies by removing the assumptions of strain tensor symmetry. This continuum theory births the proposal of a new class of physical tensors described as the Intrinsic Field Tensors capable of generalising the response of most classical mechanical metrics, a number of specialised formulations and the solutions shown to be kinematically intermediate. A series of numerical examples demonstrate Euclidean objectivity, material frame-indifference, patch test satisfaction, and agreement between the subsequent Material Principal Co-rotation and P??I??C decomposition methods that produce the intermediary stress/strain fields. The encompassing theory has wide applicability owing to its fundamental divergence from conventional mechanics, it offers non-trivial outcomes when applied to even very simple problems and its use of not the Eulerian, Lagrangian but the Intrinsic Frame generates previously unreported results in strongly orthotropic continua.

Biological ion channels are responsible for, and regulate the communication system in the body. In this thesis I develop, test and apply theoretical models of ion channels, that can relate their structure to their functional properties. Brownian dynamics simulations are introduced, in which the motions of individual ions are simulated as they move through the channel and in baths attached to each end. The techniques for setting boundary conditions which maintain ion concentrations in the baths and provide a driving potential are tested. Provided the bath size is large enough, all boundary conditions studied yield the same results. ¶ Continuum theories of electrolytes have previously been used to study ion permeation. However, I show that these continuum models do not accurately reproduce the physics taking place inside ion channels by directly comparing the results of both equilibrium Poisson-Boltzmann theory, and non-equilibrium Poisson-Nernst-Planck theory to simulations. In both cases spurious shielding effects are found to cancel out forces that play an important role in ion permeation. In particular, the `reaction field' created by the ion entering the narrow channel is underestimated. Attempts to correct these problems by adding extra force terms to account for this reaction field also fail. ¶ A model of the L-type calcium channel is presented and studied using Brownian dynamics simulations and electrostatic calculations. The mechanisms of permeation and selectivity are explained as the result of simple electrostatic interactions between ions and the fixed charges in the protein. The complex conductance properties of the channel, including the current-voltage and current-concentration relationships, the anomalous mole fraction behaviour between sodium and calcium ions, the attenuation of calcium currents by monovalent ions and the effects of mutating glutamate residues, are all reproduced. ¶ Finally, the simulation and electrostatic calculation methods are used to study the gramicidin A channel. It is found that the continuum electrostatic calculations break down in this narrow channel, as the concept of applying a uniform dielectric constant is not accurate in this situation. Thus, the permeation properties of the channel are examined using Brownian dynamics simulations without electrostatic calculations. Future applications and improvements of the Brownian dynamics simulation technique are also described.

The development of affirmative action strategies designed to achieve equal employment opportunity has been studied along six dimensions of functioning within four separate organisations. Three of these organisations were participants in the Federal Government's Affirmative Action Pilot Program in 1984/5, and one was not. It has been shown that change occurred in a continuous developmental sequence, here called an "Affirmative Action Continuum", within each of these six dimensions over the period of study, with each organisation following a similar sequence of movement. Exceptions occurred where an organisation made no movement at all, or where one or more of the sequential processes was omitted or displaced, in a dimension. The reasons for some of these exceptions, and some of their consequences for later action, have been explored. It has been shown that simultaneous activity occurred across several, dimensions, so that no organisation acted upon only one dimension in isolation from all others. There was some chronological sequencing between dimensions. The indicators of movement along the Affirmative Action Continuum within each dimension were used to describe the change process in each organisation. These indicators proved to be useful both in this regard, and in placing each organisation an the Affirmative Action Continuum in each dimension at two different points in time. In this way, the indicators' usefulness was shown to generalise to four very different institutions, thus suggesting applicability beyond the bounds of this particular study. It is intended that the results of this dissertation, and in particular the model of the Affirmative Action Continuum and the indicators described in Chapter Two, be used by Equal Employment Opportunity practitioners to facilitate their decision making about sequencing of activities designed to achieve equal employment oppportunity.

In this thesis we develop and use a continuum random walk framework to solve problems that are usually studied using a discrete random walk on a discrete lattice. Problems studied include; the time it takes for a random walker to be absorbed at a trap on a fractal lattice, the calculation of the spectral dimension for several different classes of networks, the calculation of the density of states for a multi-layered Bethe lattice and the relationship between diffusion exponents and a resistivity exponent that occur in relevant power laws. The majority of the results are obtained by deriving an expression for a Laplace transformed Green’s function or first passage time, and then using Tauberian theorems to find the relevant asymptotic behaviour. The continuum framework is established by studying the diffusion equation on a 1-d bar with non-homogeneous boundary conditions. The result is extended to model diffusion on networks through linear algebra. We derive the transformation linking the Green’s functions and first passage time results in the continuum and discrete settings. The continuum method is used in conjunction with renormalization techniques to calculate the time taken for a random walker to be absorbed at a trap on a fractal lattice and also to find the spectral dimension of new classes of networks. Although these networks can be embedded in the d- dimensional Euclidean plane, they do not have a spectral dimension equal to twice the ratio of the fractal dimension and the random walk dimension when the random walk on the network is transient. The networks therefore violate the Alexander-Orbach law. The fractal Einstein relationship (a relationship relating a diffusion exponent to a resistivity exponent) also does not hold on these networks. Through a suitable scaling argument, we derive a generalised fractal Einstein relationship which holds for our lattices and explains anomalous results concerning transport on diffusion limited aggregates and Eden trees.

Le but de cette thèse est de caractériser un continuum généré en régime femtoseconde dans une fibre microstructurée (puissance spectrale, durée des pulses, fluctuations tir à tir) et de valider son utilisation comme source optique dans des instrumentations dédiées aux domaines biologique et clinique.<br />La première application est l'élaboration d'un microscope confocal de fluorescence entièrement versatile en longueur d'onde : le continuum, filtré par un cristal acousto-optique, est ainsi utilisé comme une source accordable permettant l'excitation de n'importe quel fluorophore. Des images de cellules identifiées par différents marqueurs ont été réalisées.<br />Afin de disposer d'un outil alliant une grande versatilité spectrale à une très haute résolution spatiale, le dispositif précédent a été modifié en un microscope STED. Notre continuum est trop peu énergétique pour apporter une validation expérimentale, mais des simulations numériques prenant en compte les fluctuations du continuum permettent d'estimer que la résolution latérale peut atteindre 90 nm, voire 35 nm pour les pulses les plus puissants.<br />La troisième application est l'utilisation du continuum en tant que source large bande pulsée pour une expérience de spectroscopie de temps de vol dans les milieux diffusants tels le muscle, l'os, la moelle osseuse. Grâce à un modèle adapté de propagation de la lumière, les coefficients d'absorption, de diffusion et d'anisotropie des tissus ont été extraits des traces expérimentales, avec d'autant plus de précision que la plage spectrale utilisée est grande.<br />Même si des améliorations sont attendues, l'emploi de continua en microscopie de fluorescence et en spectroscopie est validé.

Cette thèse a deux parties. La première traite des jeux stratégiques non-atomiques, la seconde propose des applications de la théorie des jeux aux réseaux de télécommunications. Dans la première partie, les modèles de jeux non-atomiques proposés par Schmeidler (1973) et par Mas-Colell (1984) sont décrits et comparés. Nous montrons alors que ces jeux non-atomiques sont de bonnes approximations de jeux avec un nombre finis de joueurs et dans lesquels l'influence de chacun sur le paiement des autres joueurs est évanescente. Nous proposons ensuite une extension et des variations du modèle de Mas-Colell afin d'obtenir un cadre unificateur pour diverses applications des jeux non-atomiques, telles les jeux de routage, les jeux de foule et les jeux évolutionnaires. Ces trois types de jeu sont étudiés. Enfin nous étendons le concept de stratégie évolutionnairement stable au modèle de Schmeidler, ce qui donne un critère de sélection des équilibres. La deuxième partie traite de problèmes de routage dans les réseaux. Tout d'abord nous modélisons des situations où deux types de joueur partagent un réseau, des joueurs ayant une influence certaine sur la répartition des paquets dans le réseau et des joueurs n'en ayant pas. Puis, nous étudions la convergence de dynamiques de meilleures réponses dans des réseaux d'architecture simple. Finalement, nous modélisons le problème du routage mutipoint-à-multipoint.

Cette étude sur les propositions (clauses) introduites par "quand" s'ancre dans une démarche descriptive qui se veut à l'interface entre syntaxe, sémantique et discours. Il s'agit donc dans un premier temps de définir des critères permettant de rendre compte de la syntaxe particulièrement variable de cette structure introduite par quand. Nous nous sommes inspirée des travaux de Smessaert et al. (2005) pour la distinction entre micro- et macro-syntaxe et Berrendonner & Reichler-Béguelin (1989), Berrendonner (1990) et Béguelin (2004) pour la description macro-syntaxique. L'utilisation des ces outils de descriptions nous a permis de sortir de la dichotomie traditionnelle (hypotaxe vs parataxe) par l'intégration d'un niveau intermédiaire (exotaxe, épitaxe et endotaxe) afin d'élaborer un continuum scalaire d'intégration de la clause introduite par "quand", sur l'exemple de ce que propose Lehmann (1988). Ce continuum d'intégration présente une double orientation de l'intégration : de la coalescence au dégroupage et inversement. Ce continuum d'intégration syntaxique de la clause introduite par quand est corroboré par l'interprétation plus ou moins subjective de cette même clause. Nous souhaitons que ce travail soit à l'origine d'une étude plus vaste sur les intégrateurs temporels en français (cependant, alors, en même temps, à ce moment-là etc.) afin de vérifier la constance prévisible de certains phénomènes.

Thesis (M.A. (Psychology))--North-West University, Potchefstroom Campus, 2008.

This dissertation presents the development of an anisotropic viscoplastic continuum damage model to describe the permanent deformation of asphalt pavements. The model is developed to account for several phenomena that influence the permanent deformation of Asphalt Concrete (AC) at high temperatures. These phenomena include strain rate dependency, confining pressure dependency, dilation, aggregate friction, anisotropy, and damage. The model is based on Perzyna's theory of viscoplasticity with Drucker-Prager yield function modified to account for the microstructure anisotropy and damage. A parametric study was conducted to study the effect of key factors such as inherent anisotropy and damage on the model response. A preliminary investigation was conducted to demonstrate the capabilities of the model and its sensitivity to changes in the microstructure distribution and loading conditions. The model was used to describe laboratory experimental measurements obtained from the Federal Highway Administration (FHWA) Accelerated Loading Facility (ALF). The model had a good match with these experimental measurements. In particular, using the damage parameter, the model was able to capture the point at which AC experienced tertiary creep in a static creep test. A comprehensive experiment was conducted to systematically determine the model parameters and the evolution laws that describe AC hardening, anisotropy, and damage. The experiment consisted of a set of compressive triaxial strength tests conducted at three confining pressures and five strain rates. Based on these experimental measurements, the model was modified to include a nonassociated flow rule. The model was shown to capture the experimental measurements very well. Furthermore, an experiment was conducted to capture and characterize damage evolution in AC due to permanent deformation. AC specimens were loaded using a triaxial compression setup to four predefined strain levels at three confining pressures. X-Ray computed tomography and image analysis techniques were used to capture and characterize the evolution of cracks and air voids in the deformed specimens. Damage was found to be a localized phenomenon in the sense that there exists a critical section in an AC specimen that is mainly responsible for failure. The results of the damage experiment supported the damage evolution function proposed in the viscoplastic model.