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

Fungi infection in honeybee hives in regions affected by Brazilian sac brood

The Brazilian Sac Brood is a disease that affects apiaries of Africanized bee hives in Brazil, thereby making them susceptible to high losses. This study investigated the pathogenicity of Africanized bee hives by the entomopathogenic fungi in a Brazilian Sac Brood endemic region. The degree of fungal contamination, presence of mycotoxins in beehive elements, and vulnerability of healthy beehives in environments subjected and not subjected to the disease were investigated. From the contaminating fungal load, species that are mycotoxin producers and pathogenic causing mortality in the bees have been isolated. The analysis of bee pollen and bee bread samples did not show the presence of the toxic pollen of Stryphnodendron (Fabaceae), which has been indicated as the causative agent of mortality in pre-pupal stage larvae. However, bee bread showed the highest correlation between substrate and fungal contamination

Ochratoxin A in wines from 2002 to 2008 harvest marketed in Rio de Janeiro, Brazil

The occurrence of ochratoxin A (OTA) in wine from 2002 to 2008 harvest, traded in Rio de Janeiro State, was evaluated by analysing 43 national and 37 imported wines from Argentina (32) and Chile (5), adding up to 80 samples in total. OTA determination was performed using immunoaffinity columns and high-performance liquid chromatography. In 80 wine samples analysed, 25 (31.3%) were positive, presenting levels greater than 0.020 ng OTA mL(-1). It was not detected in imported wines. Within national wines, 58.1% of the samples were contaminated, with levels ranging from 0.020 to 0.050 ng mL(-1). The toxin was detected in 18 (69.2%) of 26 samples analysed of red table wine. Wines from 2008 harvest presented 84.6% of samples contaminated in 13 samples analysed. Despite the levels found in this study, they are below Brazilian tolerance limits. Nevertheless, the presence of OTA as found contributes to the human exposure to this toxin