Doctor of Philosophy / The main issue to be articulated in this thesis is the proposition that Leibniz’s mature philosophy is best, or preferably, presented as a double-aspect ontology. All the arguments to be furnished herein support this case; however, their intrinsic weight and extent far exceeds that of the principal contention, so that the whole of Leibniz’s natural philosophy and metaphysics will be seen to be involved and to undergo some measure of re-orientation away from more traditional interpretive concerns. Part I follows Leibniz in his emendation of Aristotelian-Scholastic notions as a result of his need for a “higher, metaphysical principle” to remedy the defects of the ‘modern’ account of motion. From this flowed his new conception of substance. The fundamental premise of Leibniz’s metaphysics is that spirit and body lie in series. The cosmos presents itself as aspects of an unbroken continuum. Ineluctably our conclusions as to the ‘whole’ is therefore an intellectual reconstruction of the perspectives delivered to us by these aspects. This emerges most clearly from the phenomenotaxis which has been collated in this part of the thesis – apparently the first such exercise in the scholarly literature. All this involves a separation of domains which require appropriate levels of description to explain their autonomous features. A double-aspect theory seems indispensable to account for the one world to which these levels nonetheless refer. In Part II we engage with Leibniz’s conception of substance as a unit of force. From this protean idea (aka monad) the whole material and spiritual cosmos is derived. The basis of this theory is that to act is to be. Accordingly we arrive at an ontology of agency. The nature of a monad is to exert Daseinstreben, the equivalent of individuation. Included in its definition is an absolute freedom to act. God’s “concession” of existence therefore refers to the autonomous collectivisation of monads into universes eligible for actualisation. Accordingly Leibniz arrives at a theory of a self-constructing universe. Post-Arnauld, Leibniz discarded the complete concept, having realised that contingency breaks open the system of determinism. Accordingly Leibniz replaced the ‘sum of predicates’ doctrine with the law of the series. In this conception monads collect the asymmetrical and irreversible information relevant to their internal states; for it transpires that freely executed choices guarantee avoidance of indiscernibles. The section therefore presents a schema of the ten main issues entangled in the conception of agency as well as an analytical chart of the structure of monads. In Part III, the “Labyrinth of the Continuum” resolves the perspectives on the world. Leibniz declares his colours unambiguously – realism concerns the world of facts, idealism the realm of foun-dations. The Principle of Continuity covers a vast range of indeterminate parts which serve as the foundations of real parts. We investigate some case studies, e.g. petites perceptions and especially the Pacidius, in which the conception of an agent-in-motion is studied in depth to reveal Leibniz’s extraordinary conclusions on change. We also consider Shapes, Limits and Boundaries which are relevant to the theory of the self-constructing universe (infolding and unfolding order); and finally his models of self-similarity and scale invariance. PART IV is concerned with grounding existents from the principle of sufficient reason. The virtue claimed here for the double-aspect theory is the possibility of penetrating into the thought of an exceptionally complex thinker through more than one portal. It yields a greater variety of facets, an inner coherence and a much richer texture of thought than the traditional insistence on just one primary aspect reveals.

Les interneurones GABAergiques sont des composants cruciaux du réseau neocortical et la caractérisation fonctionnelle du neocortex a été fortement ralentie par l'absence de consensus concernant leur classification. Les interneurones se différencient du point de vue électrophysiologique et morphologique ainsi que par l'expression de marqueurs moléculaires. Une controverse demeure cependant, pour déterminer si la combinaison de ces caractéristiques définit des classes séparées ou au contraire, un continuum phénotypique où chaque cellule est unique. Pendant ma thèse, je me suis proposé d'étudier la diversité des interneurons neocorticaux en prenant en compte l'ensemble de ces critères. Des enregistrements de patch-clamp couplés à la technique de PCR sur cellule unique ont été réalisés sur un échantillon de plus de 300 interneurones et l'arborisation de près de 200 d'entre eux a été reconstruites en 3 dimensions. Les phénotypes électrophysiologiques, morphologiques et moléculaires de notre échantillon ont été quantifiés au travers d'un ensemble de 56 paramètres quantitatifs. Cet échantillon a d'abord été utilisé pour caractériser les interneurones dans la couche VI du neocortex, une région où ils n'avaient été que partiellement décrits. En utilisant une approche non supervisée, 4 classes d'interneurones ont pu être identifiées sur la base de propriétés électrophysiologiques, morphologiques et moléculaires. Additionnellement, en utilisant des immunomarquages sur des souris GAD67::GFP Knock-In, les distributions d'interneurones exprimant des marqueurs caractéristiques ont été cartographiées à travers la couche VI, mettant en évidence que des populations distinctes s'accumulent dans des sous-couches particulières. Ces analyses ont été soumises pour publication. Nous avons ensuite entrepris de caractériser la diversité des interneurones à travers l'ensemble des couches du neocortex. En utilisant des méthodes non supervisées reposant sur les propriétés électrophysiologiques et moléculaires des interneurones, nous avons montré que les classes que nous avions caractérisées dans la couche VI pouvaient être identifiées sur l'ensemble de notre échantillon. Toutefois, en analysant la séparation de ces classes avec des méthodes analytiques, nous avons trouvé que, si certaines formaient des archétypes distincts, une fraction substantielle de notre échantillon présentait des phénotypes intermédiaires à des classes particulières. Ce travail suggère donc que les interneurones du neocortex se séparent bien en plusieurs populations, mais que ces groupes ne constituent pas des classes distinctes mais plutôt des archétypes phénotypiques. Ces résultats supportent une nouvelle façon de regarder la diversité des interneurones GABAErgiques et seront rapportés dans un second article.

<p>Continuum mechanics is used to model the mechanical behaviour of concrete structures subjected to high rates of loading in defence applications. Large deformation theory is used and an isotropic elastic-plastic constitutive equation with isotropic hardening, damage and strain rate dependent loading surface. The hydrostatic pressure is governed by an equation of state. Numerical analysis is performed using the finite element method and the central difference method for the time integration.</p><p>Projectile penetration is studied and it is concluded that it is not suitable to use material description of the motion of both the target and the projectile together with an erosion criterion. Instead, the material description should be used only for the projectile and the spatial description for the target. In this way the need for an erosion criterion is eliminated. Also, in the constitutive model used it is necessary to introduce a scaling of the softening phase in relation to the finite element size, in order to avoid strain localization.</p><p>Drop weight testing of reinforced concrete beams are analysed, where a regularisation is introduced that renders mesh objectivity regarding fracture energy release. The resulting model can accurately reproduce results from material testing but the regularisation is not sufficient to avoid strain localization when applied to an impact loaded structure. It is finally proposed that a non-local measure of deformation could be a solution to attain convergence.</p><p>The third study presents the behaviour of a concrete constitutive model in a splitting test and a simplified non-local theory applied in a tensile test. The splitting test model exhibits mesh dependency due to a singularity. In the tensile test the non-local theory is shown to give a convergent solution. The report https://www.diva-portal.org/liu/webform/form.jsp#paper0is concluded with a discussion on how to better model concrete materials.</p>

While rheological and microstructural complexities have posed tremendous challenges to researchers in developing first principles models and simulation techniques that can accurately and robustly predict the dynamical behaviour of polymeric flows, the past two decades have offered several significant advances towards accomplishing this goal. These accomplishments include: (1). Stable and accurate formulation of continuum-level viscoelastic constitutive models and their efficient implementation using operator splitting methods to explore steady and transient flows in complex geometries, (2). Prediction of rheology of polymer solutions and melts based on micromechanical models as well as highly parallel self-consistent multiscale simulations of non-homogeneous flows. The main objective of this study is to leverage and build upon the aforementioned advances to develop a quantitative understanding of the flow-micro-structure coupling mechanisms in viscoelastic polymeric fluids and in turn predict, consistent with experiments, their essential macroscopic flow properties e.g. frictional drag, interface shape, etc. To this end, we have performed extensive continuum and multiscale flow simulations in several industrially relevant bulk and free surface flows. The primary motivation for the selection of the specific flow problems is based on their ability to represent different deformation types, and the ability to experimentally verify the simulation results as well as their scientific and industrial significance.

No description available.

The continuum theory provides a framework in which the growth of a plant root as a dynamic process involving interactions among transport of water and solute, cell division, and the subsequent cell elongation can be described. A plant root is modeled as a one-dimensional, multi-phase, mathematical continuum. The network of cell walls constitute the solid phase of the system. The symplast and the apoplast pathways reside in this network of cell walls. Water and carbohydrates move in opposite directions through the apoplast and symplast pathways within the deforming network of cell walls. The division and elongation of cells depends on the mechanical stress imposed on the cell walls, the rate of metabolic stress relaxation process, and the physical properties of the cell walls. The model consists of five systems of differential equations. The kinematic equations are derived which allow, specifically, the different roles of cell division and elongation in root growth to be considered. These provide the reference system of the model. Equations of water transport in the coupled system of apoplast and symplast pathways are derived from considerations of theories of transport in the porous media and the cellular and membrane properties of the plant root. Equations of solute transport are derived by considering, specifically, the mechanisms involved in solute transport both at the membranes separating individual cells and within the cytoplasm. The rate of cell elongation is described as a function of the mechanical stress in the cell walls, the viscoelastic properties of the cell walls, and a metabolically controlled strain energy relaxation process. Growth in the meristem is modeled as the result of continuous cell elongation and division. The equations of water and solute transport, cell elongation, and meristem growth are solved simultaneously under the reference system provided by the kinematic theory. The model is used to examine the effects of soil water stress, soil resistance to root penetration, and temperature, as well as the carbohydrate supply from the upper part of the plant on the dynamic process of root elongation. The close correspondence between the material coordinate system and the underlying cellular structure of the root allows the comparison between the continuum theory and the results of cell growth studies. Agreement of the model predictions of the pattern of growth along the root axis, as well as the effects of temperature and soil water stress on root growth, with the experimental measurements reported in the literature provides the justification for the theories. / Graduation date: 1991

No description available.

In modern democratic country, the complexity of public affairs is a difficult topic of public policy. Only admires the objective analysis technology is insufficient to in accordance to the complex public decision-making. Therefore, the public policy formulation needs the suitable political judgment. But populace's policy-making cognition mode then is the key to carry out the policy formulation. Today Taiwan society had the certain democratized degree and the economic basis, the populace had opportunity to participate in public affairs. As a result of is extremely insufficient in the participation public affairs training, the populace has not been able by rational when discuss the public subject that he faces. Here cognition is uncoordinated and possible to initiate the policy-making conflict. If we want to reduce the policy-making conflict to achieve higher policy-making quality, it is the necessary thorough understanding common populace's policy-making cognition mode. This research is based on the Cognitive Continuum Theory, take sets up a wetland park as the example, designs a quasi-experiment to directly compares efficacies of analytical, intuitive and quasi-rational cognition mode of the populace in the public decision-making. The research target lies in to regards the analytical cognition and the intuitive cognition is dichotomous proposes the counter-evidence, proved they are the beginnings and ends of the cognitive continuum. The findings showed that, (1) the characteristic policy-making judgment cognition mode of the populace to the wetland park judgment is a continuous distribution state. (2) The cognition identity of judgment method to be able to induce the cognition identity of the policy-making judgment. (3) The populace's policy-making judgment behavior has the analysis cognition identity that they can depend on analytical judgment method to carry on the policy-making judgment. (4) The policy-making cognition mode can come under cognition of identity influence the policy-making judgment method. The better correlation of judgment method and the goal cognition identity, the more consistent policy-making performance.

Hot mix asphalt (HMA) is a granular composite material stabilized by the presence of asphalt binder. The behavior of HMA is highly influenced by the microstructure distribution in terms of the different particle sizes present in the mix, the directional distribution of particles, the distribution of voids, and the nucleation and propagation of cracks. Conventional continuum modeling of HMA lacks the ability to explicitly account for the effect of microstructure distribution features. This study presents the development of elastic and visco-plastic models that account for important aspects of the microstructure distribution in modeling the macroscopic behavior of HMA. In the first part of this study, an approach is developed to introduce a length scale to the elasticity constitutive relationship in order to capture the influence of particle sizes on HMA response. The model is implemented in finite element (FE) analysis and used to analyze the microstructure response and predict the macroscopic properties of HMA. Each point in the microstructure is assigned effective local properties which are calculated using an analytical micromechanical model that captures the influence of percent of particles on the microscopic response of HMA. The moving window technique and autocorrelation function are used to determine the microstructure characteristic length scales that are usedin strain gradient elasticity. A number of asphalt mixes with different aggregate types and size distributions are analyzed in this paper. In the second part of this study, an elasto-visco-plastic continuum model is developed to predict HMA response and performance. The model incorporates a Drucker- Prager yield surface that is modified to capture the influence of stress path direction on the material response. Parameters that reflect the directional distribution of aggregates and damage density in the microstructure are included in the model. The elasto-visco-plastic model is converted into a numerical formulation and is implemented in FE analysis using a user-defined material subroutine (UMAT). A fully implicit algorithm in time-step control is used to enhance the efficiency of the FE analysis. The FE model used in this study simulates experimental data and pavement section.

Thesis (M.A.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains v, 75 p. : ill., maps (some col.). Includes abstract. Includes bibliographical references (p. 53-57).