1,107 research outputs found
Development of a computer program to simulate the predictions of the replaced elements model of Pavlovian conditioning
Vogel, E.H. Universidad de Talca, Escuela de PsicologĂa, Casilla N° 747, Talca, Chile.
Disponible http://www.psicothema.com/pdf/3392.pdfPese a la aparente simpleza del condicionamiento pavloviano, la investigaciĂłn acerca de sus mecanismos ha despertado considerable debate, como es el caso de la disputa acerca de si los estĂmulos que se asocian son codificados en forma >(un estĂmulo compuesto es equivalente a la suma de sus componentes) o >(un estĂmulo compuesto es un ejemplar Ăşnico). Esta controversia es evidente en la abundante investigaciĂłn sobre las predicciones contrastantes de los modelos elementalistas y configuracionales. Recientemente, han surgido soluciones mixtas, con las ventajas de ambos enfoques, pero difĂciles de evaluar dada su complejidad. Este artĂculo presenta un programa computacional para ejecutar simulaciones de un modelo mixto (replaced elements model o REM). Se incluyen instrucciones y ejemplos para utilizar el simulador con fines investigativos y educacionales
Battery Manufacturing Resource Assessment to Minimise Component Production Environmental Impacts
A promising route to attain a reliable impact reduction of supply chain materials is based on considering circular economy approaches, such as material recycling strategies. This work aimed to evaluate potential benefits of recycling scenarios for steel, copper, aluminium and plastic materials to the battery manufacturing stage. Focused on this aim, the life cycle assessment (LCA) and the environmental externalities methodologies were applied to two battery study cases: lithium manganese oxide and vanadium redox flow (VRFB) batteries, based on a cradle-to-gate LCA approach. In general, the results provided an insight into the raw material handling route. Environmental impacts were diminished by more than 20% in almost all the indicators, due to the lower consumption of virgin materials related to the implemented recyclability route. Particularly, VRFB exhibited better recyclability ratio than the Li-ion battery. For the former, the key components were the periphery ones attaining around 70% of impact reduction by recycling steel. Components of the power subsystem were also relevant, reaching around 40% of environmental impact reduction by recycling plastic. The results also foresaw opportunities for membranes, key components of VRFB materials. Based on findings, recycling strategies may improve the total circularity performance and economic viability of the studied systems
Monte Carlo simulation of metal deposition on foreign substrates
The deposition of a metal on a foreign substrate is studied by means of grand
canonical Monte Carlo simulations and a lattice-gas model with pair potential
interactions between nearest neighbors. The influence of temperature and
surface defects on adsorption isotherms and differential heat of adsorption is
considered. The general trends can be explained in terms of the relative
interactions between adsorbate atoms and substrate atoms. The systems
Ag/Au(100), Ag/Pt(100), Au/Ag(100) and Pt/Ag(100) are analyzed as examples.Comment: 26 pages, 9 figure
Application of Model-driven engineering to multi-agent systems: a language to model behaviors of reactive agents
Many users of multi-agent systems (MAS) are very commonly disinclined to model and simulate using current MAS platforms. More specifically, modeling the dynamics of a system (in particular the agents' behaviors) is very often a challenge to MAS users. This issue is more often observed in the domain of socio-ecological systems (SES), because SES domain experts are rarely programmers. Indeed, the majority of MAS platforms were not conceived taking into consideration domain-experts who are non-programmers. Most current MAS tools are not dedicated to SES, or nor do they possess an easily understandable formalism to represent the behaviors of agents. Moreover, because it is platform-dependent, a model realized in a given MAS platform cannot be properly used on another platform due to incompatibility between MAS platforms. To overcome these limitations, we propose a domain-specific language (DSL) to describe the behaviors of reactive agents, regardless of the MAS platform used for simulation. To achieve this result, we used model-driven engineering (MDE), an approach that provides tools to develop DSLs from a meta-model (abstract syntax), textual editors with syntax highlighting (for the concrete syntax) and code generation capabilities (for source-code generation of a model). As a result, we implemented a language and a textual editor that allow SES domain experts to describe behaviors in three different ways that are close to their natural expression: as equations when they are familiar with these, as a sequence of activities close to natural language or as an activity diagram to represent decisions and a sequence of behaviors using a graphic formalism. To demonstrate interoperability, we also developed code generators targeting two different MAS platforms (Cormas and Netlogo). We tested the code generators by implementing two SES models with the developed DSL. The generated code was targeted to both MAS platforms (Cormas and Netlogo), and successfully simulated in one of them. We conclude that the MDE approach provides adequate tools to develop DSL and code generators to facilitate MAS modeling and simulation by non-programmers. Concerning the DSL developed, although the behavioral aspect of MAS simulation is part of the complexity of modeling in MAS, there are still other essential aspects of model and simulation of MAS that are yet to be explored, such as model initialization and points of view on the model simulated worl
Heritability of fasting glucose levels in a young genetically isolated population
Aims/hypothesis: The heritability of fasting glucose levels in Northern European populations has been examined previously in twins and samples of small pedigrees. In this study the heritability of fasting plasma glucose (FPG) was estimated in participants in the Erasmus Rucphen Family study, who were members of a single pedigree from a young genetic isolate. We also studied the relationship between FPG and components of the metabolic syndrome. Methods: FPG, lipid, blood pressure and body composition measurements were completed for 852 participants without diabetic medication. The most significant predictors of FPG were used as covariates in heritability estimation. The sibship effect, which is a composite of genetic dominance and shared early-life environmental effects, was included as a random effect. Results: The age- and sex-adjusted heritability of log normal-transformed FPG was 36.6%. When further adjusted for metabolic risk factors, namely body composition parameters, systolic blood pressure, triglycerides and cholesterol:HDL ratio, the heritability estimate rose to 42.8%. After adjustment for the sibship effect, the additive component of heritability was estimated to be 28.3% (age-and sex-adjusted) and 24.9% (full model). Conclusions/ interpretation: Genes control a significant proportion of the variance in FPG levels. Adjustment for other metabolic risk factors did not substantially change the heritability estimate, which suggests that a large part of the variance in FPG levels is due to genes that act through pathways that are independent of those controlling body composition, blood pressure and lipid levels
Bound Pairs: Direct Evidence for Long-range Attraction between Like-Charged Colloids
We report observations of stable bound pairs in very dilute deionized aqueous
suspensions of highly charged polystyrene colloidal particles, with monovalent
counterions, using a confocal laser scanning microscope. Through an analysis of
several thousands of time series of confocal images recorded deep inside the
bulk suspension, we find that the measured pair-potential, U(r) has a
long-range attractive component with well depths larger than the thermal
energy. These observations provide a direct and unequivocal evidence for the
existence of long-range attraction in U(r) of like-charged colloidal particles.Comment: 8 pages, 4 figures, submitted to Phys. Rev. Let
Simulation of Channel Segregation During Directional Solidification of In—75 wt pct Ga. Qualitative Comparison with In Situ Observations
International audienceFreckles are common defects in industrial casting. They result from thermosolutal convection due to buoyancy forces generated from density variations in the liquid. The present paper proposes a numerical analysis for the formation of channel segregation using the three-dimensional (3D) cellular automaton (CA)—finite element (FE) model. The model integrates kinetics laws for the nucleation and growth of a microstructure with the solution of the conservation equations for the casting, while introducing an intermediate modeling scale for a direct representation of the envelope of the dendritic grains. Directional solidification of a cuboid cell is studied. Its geometry, the alloy chosen as well as the process parameters are inspired from experimental observations recently reported in the literature. Snapshots of the convective pattern, the solute distribution, and the morphology of the growth front are qualitatively compared. Similitudes are found when considering the coupled 3D CAFE simulations. Limitations of the model to reach direct simulation of the experiments are discussed
Diabetes, Diabetic Complications, and Fracture Risk
Diabetes and osteoporosis are both common diseases with increasing prevalences in the aging population. There is increasing evidence corroborating an association between diabetes mellitus and bone. This review will discuss the disease complications of diabetes on the skeleton, highlighting findings from epidemiological, molecular, and imaging studies in animal models and humans. Compared to control subjects, decreased bone mineral dens
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