Determination of the drag coefficient of an autonomous solar lighting column using wind tunnel simulation and computational analysis

The Sun is the largest source of energy available and many studies for the development of technologies capable of harnessing this energy are constantly being conducted. Among the technologies developed are photovoltaic solar panels that have many applications and among them are the autonomous solar lighting columns that have been growing in popularity especially in urban and industrial environments. These columns are installed in open regions and have their structure exposed to the mechanical actions imposed by the wind, so they need to be correctly designed to support them. There are aerodynamic variables that must be determined for the design of these columns, especially the drag coefficient, a property linked to the geometry of a body, which represents its interaction with a flowing fluid. Due to the complexity of determining these variables, experimental methods are constantly used to obtain these values. Classically, wind tunnel simulations are used for this purpose, but they can be expensive and difficult to perform. Fluid dynamic computational analysis has been widely applied to replace physical analysis. In this work, the drag coefficient of an autonomous solar lighting column is determined by wind tunnel simulations and computational analysis. With the obtained results, a comparison is made to verify the fidelity of the data obtained by computational means when compared to those obtained through the wind tunnel simulations.info:eu-repo/semantics/publishedVersio

Saccharomyces cerevisiae strains and the reduction of Aspergillus parasiticus growth and aflatoxin B1 production at different interacting environmental conditions, in vitro

The effect of Saccharomyces cerevisiae RC008 and RC016, previously selected based on their aflatoxin B1 binding ability and beneficial properties, against Aspergillus parasiticus under different interacting environmental conditions was evaluated. Studies concerning the lag phase, growth rate and aflatoxin B1 production were carried out in vitro under different regimes of aw (0.95 and 0.99), pH (4 and 6), temperature (25 and 37°C), and oxygen availability (normal and reduced). Both yeast strains showed great antagonistic activity at pH 4, decreasing growth rate compared with the control. The RC008 strain showed the greatest inhibitory activity at all assayed conditions. A. parasiticus produced large amounts of AFB1in vitro. A significant decrease of AFB1 levels in comparison with the control were observed with yeast interaction. Differences between control and treatment values ranged from 130 to 5400 ng ml-1. S. cerevisiae RC008 and RC016 could be considered as effective agents in reducing growth and AFB1 production at different interacting environmental conditions, related to that found in stored feedstuff. The importance of the present work lies in the search for live strains with both probiotic and biocontrol properties able to prolong the safe storage of feedstuff and exert beneficial properties after animal consumption and which could be included in a novel product for animal feed. © 2012 Copyright Taylor and Francis Group, LLC.Fil: Armando, María Romina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Dogi, Cecilia Ana. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Instituto de Ciencias Veterinarias. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Ciencias Veterinarias.; ArgentinaFil: Rosa, C.A.R.. Conselho Nacional de Desenvolvimiento Científico e Tecnológico; Brasil. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Dalcero, Ana Maria. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cavaglieri, Lilia Reneé. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentin

Formal Modeling of a Generic Middleware to Ensure Invariant Properties

International audienceThe complexity of middleware leads to complex Application Programming Interfaces (APIs) and semantics, supported by configurable components in the middleware. Those components are selected to provide the desired semantics. Yet, incorrect configuration can lead to faulty middleware executions, detected late in the development cycle.We use formals methods to tackle this problem. They allow us to find appropriate composition of middleware components and the use of their APIs, and to detect valid or faulty sequences. To provide reusable results, we modeled a canonical middleware architecture using Z.We propose a validation scenario to verify middleware’s invariants. We define invariants to exhibit inconsistent usage of these APIs. The specification has been checked with the Z/EVES [13] theorem prover