Coupling of Rigorous Multiphase Flash with Advanced Linearization Schemes for Accurate Compositional Simulation

The properties of fluids flowing in a petroleum reservoir are quantified by understanding the thermodynamic behavior of each flowing phase in the system. This work describes proper techniques to formulate and execute a thermodynamic model for accurately predicting the equilibrium behavior of oil-gas-brine systems within the practical range of pressure and temperature. The three-phase flash algorithm is validated against published data from the available literature. The multiphase flash procedure is implemented to generate linearized physical properties by using an Operator Based Linearization (OBL) modelling technique allowing for a combination of multiple complex physics in the nonlinear solution of governing equations. This is the first implementation of three-phase flash calculations for hydrocarbons and brines based on fugacity-activity models coupled with an advanced highly efficient linearization scheme. Our approach increases the efficiency and flexibility of the modelling process of physical phenomena such as fluid flow in porous subsurface reservoirs.

Empirical Support for the Tenets of Sport Participation and Physical Activity-Based Models: A Scoping Review

Notwithstanding their wide-spread use, it is unclear what level of empirical evidence exists to support sport participation and physical activity-based models. Sport participation and physical activity-based models characterize different stages of sport involvement based on sport activities (organized and unorganized) individuals take part in throughout their lifespan. The objectives of this scoping review was to explore the nature of empirical support for tenets of sport participation and physical activity-based models describing the evolution of an individuals' sport participation. Seventeen different sport participation models were identified through an iterative literature review, using a snowball search strategy and expert (n = 8) consultation. Of the identified models, three described the evolution of an individual's sport participation based on their participation in different activities at various stages of sport involvement and were retained for the review. A second literature review identified peer-reviewed publications supporting at least one tenet of these three models. Many tenets of retained models received some empirical support from some of the 38 publications identified, but some tenets were not tested. Most of the evidence supporting tenets originated from studies among elite-level athletes. Whereas some evidence exists to support current sport participation and physical activity models, more research is warranted, particularly among the general population of non-elite athletes, for the models to be used in full confidence to guide sport policies, programs, and practices.

Dynamics of an artificial recurrent neural network for the problem of modeling a cognitive function

The purpose of this work is to build an artificial recurrent neural network whose activity models a cognitive function relating to the comparison of two vibrotactile stimuli coming with a delay and to analyze dynamic mechanisms underlying its work. Methods of the work are machine learning, analysis of spatiotemporal dynamics and phase space. Results. Activity of the trained recurrent neural network models a cognitive function of the comparison of two stimuli with a delay. Model neurons exhibit mixed selectivity during the course of the task. In the multidimensional activity, the components are found each of which depends on a certain task parameter. Conclusion. The training of the artificial neural network to perform the funciton analogous to the experimentally observed process is accompanied by the emergence of dynamic properties of model neurons which are similar to those found in the experiment.

A domain specific language notation for a language learning activity generation tool

Globalization has increased the need for society to master new languages. This need has encouraged the launch of many applications dedicated to language learning. This paper presents a graphical notation for a domain specific language to represent language learning activities. It describes how this notation enables developers to represent language learning activity characteristics using workflow, presentation, content, media and activity model conforming a metamodel that defines the abstract syntax of the domain specific language. This notation is implemented as part of an integrated development environment to build model-based applications. Finally, this proposal is evaluated with a framework that uses the cognitive dimensions of notations for notational systems. The proposed graphic diagram editor exceeds the experience that the user has with the reflexive model editor. In relation to the creation and editing of workflow models and presentation/activity models, the proposed graphical notation its more intuitive and easy to maintain visually than the traditional reflexive tree notation used by many model-based development frameworks.

Phytochemical screening and evaluation of the antioxidant and anti-bacterial activity of Woundwort (Anthyllis vulneraria L.)

For millennia, medicinal plants have been used to prevent and cure diseases. Up to now there is a growing interest in their use in several areas as conducted for Anthyllis in our investigation. Actually the present research aims to investigate the biochemical characterisation of a medicinal plant collected from Tunisia named Woundwort [Anthyllis vulneraria L. (Jones and Turrill 1933)] by determining the mineral content, phenolic compound contents and biological activities of its leaf and flower extracts. On the one hand, the results obtained showed that A. vulneraria accumulated minerals at different amounts with significant differences between leaves and flowers extracts. On the other hand, the data revealed that the hydroethanolic flower extract contained the highest content of total polyphenols, flavonoids and condensed tannin, as it exhibited the strongest antioxidant activity. The flower extract also showed better antibacterial effect than leaf extract. These results support the exploitation of active compounds extracted from the leaves and especially the flowers of A. vulneraria, which can provide new alternatives to the use of certain drugs, additives, among others, as they can be used as structure–activity models for the development of new products.

The effects of taxes on wealth inequality in Artificial Chemistry models of economic activity

We consider a number of Artificial Chemistry models for economic activity and what consequences they have for the formation of economic inequality. We are particularly interested in what tax measures are effective in dampening economic inequality. By starting from well-known kinetic exchange models, we examine different scenarios for reducing the tendency of economic activity models to form unequal wealth distribution in equilibrium.

Cross talk-dependent cortical patterning of Rho GTPases during cell repair

Rho GTPases such as Rho, Rac and Cdc42 are important regulators of the cortical cytoskeleton in processes including cell division, locomotion and repair. In these processes, Rho GTPases assume characteristic patterns wherein the active GTPases occupy mutually exclusive “zones” in the cell cortex. During cell wound repair, for example, a Rho zone encircles the wound edge and is in turn encircled by a Cdc42 zone. Here we evaluated the contributions of crosstalk between Rho and Cdc42 to the patterning of their respective zones in wounded Xenopus oocytes using experimental manipulations in combination with mathematical modeling. The results show that the position of the Cdc42 zone relative the Rho zone and relative to the wound edge is controlled by the level of Rho activity. In contrast, the outer boundary of the Rho zone is limited by the level of Cdc42 activity. Models based on positive feedback within zones and negative feedback from Rho to the GEF-GAP Abr to Cdc42 capture some, but not all, of the observed behaviors. We conclude that GTPase zone positioning is controlled at the level of Rho activity and we speculate that the Cdc42 zone or something associated with it limits the spread of Rho activity. [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text]