Search results for "Stirling"
showing 6 items of 26 documents
The pure descent statistic on permutations
2017
International audience; We introduce a new statistic based on permutation descents which has a distribution given by the Stirling numbers of the first kind, i.e., with the same distribution as for the number of cycles in permutations. We study this statistic on the sets of permutations avoiding one pattern of length three by giving bivariate generating functions. As a consequence, new classes of permutations enumerated by the Motzkin numbers are obtained. Finally, we deduce results about the popularity of the pure descents in all these restricted sets. (C) 2017 Elsevier B.V. All rights reserved.
A Numerical Optimisation of a Stirling Engine
2011
International audience; A zero dimensional finite-time thermodynamic, three zones model of a generic Stirling engine has been developed and experimentally validated. Taking into account time-dependant heat transfers and losses, the model calculates the evolution of gas temperature, mass and pressure in each zone.
Development of Neural Network Prediction Models for the Energy Producibility of a Parabolic Dish: A Comparison with the Analytical Approach
2022
Solar energy is one of the most widely exploited renewable/sustainable resources for electricity generation, with photovoltaic and concentrating solar power technologies at the forefront of research. This study focuses on the development of a neural network prediction model aimed at assessing the energy producibility of dish–Stirling systems, testing the methodology and offering a useful tool to support the design and sizing phases of the system at different installation sites. Employing the open-source platform TensorFlow, two different classes of feedforward neural networks were developed and validated (multilayer perceptron and radial basis function). The absolute novelty of this approac…
Energy and Environmental Assessment of a Hybrid Dish-Stirling Concentrating Solar Power Plant
2022
Although the 2019 global pandemic slowed the growing trend of CO2 concentrations in the atmosphere, it has since resumed its rise, prompting world leaders to accelerate the generation of electricity from renewable sources. The study presented in this paper is focused on the evaluation of the energy and environmental benefits corresponding to the hypothesis of hybridizing a dish-Stirling plant installed on the university campus of Palermo (Italy). These analyses were carried out by means of dynamic simulations based on an accurate energy model validated with the experimental data collected during the measurement campaign that occurred during the period of operation of the reference plant. As…
On the spatial spread of a pattern
1980
A simple process is considered for the spread of a pattern in a spatially distributed population. Expressions are given for the stochastic means, variances and covariances. Central limit theorems are obtained for the number of individuals that have the pattern, and the time needed for the pattern to reach the n-th subpopulation.
MODELLING, OPTIMIZATION, AND 3E-ANALYSIS OF DISH-STIRLING CONCENTRATING SOLAR POWER SYSTEMS
2022
raggiungimento degli obiettivi del precedente Accordo di Parigi, tutti i Paesi sono stati invitati a impegnarsi a garantire l'azzeramento globale entro la metà del secolo e a mantenere l'aumento della temperatura media globale significativamente al di sotto dei 2 °C, rispetto ai livelli preindustriali, entro il 2050, e più precisamente entro il limite superiore di 1,5 °C. Tutti i Paesi stanno concentrando le loro politiche su una transizione energetica globale che consiste nell'aumento dell'uso di fonti rinnovabili per la generazione di elettricità e nell'uso diretto di calore e biomassa rinnovabili, nell'uso diretto di elettricità pulita nei trasporti e nelle applicazioni termiche, nel mig…