Classification of Triadic Chord Inversions Using Kohonen Self-organizing Maps

In this paper we discuss the application of the Kohonen Selforganizing Maps to the classification of triadic chords in inversions and root positions. Our motivation started in the validation of Schönberg´s hypotheses of the harmonic features of each chord inversion. We employed the Kohonen network, which has been generally known as an optimum pattern classification tool in several areas, including music, to verify that hypothesis. The outcomes of our experiment refuse the Schönberg´s assumption in two aspects: structural and perceptual/functional

Spatial patterns and biodiversity in off-lattice simulations of a cyclic three-species Lotka-Volterra model

Stochastic simulations of cyclic three-species spatial predator-prey models are usually performed in square lattices with nearest neighbor interactions starting from random initial conditions. In this Letter we describe the results of off-lattice Lotka-Volterra stochastic simulations, showing that the emergence of spiral patterns does occur for sufficiently high values of the (conserved) total density of individuals. We also investigate the dynamics in our simulations, finding an empirical relation characterizing the dependence of the characteristic peak frequency and amplitude on the total density. Finally, we study the impact of the total density on the extinction probability, showing how a low population density may jeopardize biodiversity.Comment: 5 pages, 7 figures; new version, with new title and figure

Strategy to improve the residual diametric structure of Cedrela odorata for a new cutting cycle.

IUFROLAT 2013. Disponibilizado online. Resumen

Estabelecimento de área de coleta de sementes de tucumã-do-pará.

bitstream/item/43031/1/Com-Tec-225.pdfVersão eletrônica

Impact of biofilms in simulated drinking water and urban heat supply systems

Biofouling and biocorrosion were studied in drinking water and heating water systems by forming biofilms on steel and on polymethylmetacrylate. In the drinking water system, biofilm development was more significant on corroded surfaces, suggesting that in these conditions they were largely protected from disinfection, probably because of sheltering and chlorine demand by corrosion products. In the urban heat supply system, results suggest a higher biofilm activity at lower pH. Sulphate-reducing bacteria were detected in the urban heating biofilms, but little corrosion was observed on steel coupons. Results indicate that surface and bulk medium properties, as well as bacterial diversity are determinant parameters when studying biofouling and biocorrosion.Cirius – Danish Centre for International Cooperation and Mobility in Education and Trainin

The influence of surface material on the development of Desulfovibrio desulfuricans biofilms

Sulphate reducing bacteria have an important role in the sulphur cycle, and therefore in wastewater treatment systems. They are able to form biofilms on metallic surfaces, leading to fouling and corrosion problems. Additionally, hydrogen sulphide that is a product of their metabolism can cause serious health risks. In this study, sulphate reducing bacteria (SRB) biofilms were developed on stainless steel 304 and on polycarbonate in order to evaluate surface effect on biofilm formation. Results showed that the biofilm formed on stainless steel presented higher metabolic activity, confirmed by lactate and sulfate removals. Metal elements present in stainless steel may affect SRB activity. This can be the case of nickel that represents around 8% of stainless steel 304. Studies performed with suspended cultures of Desulfovibrio desulfuricans also showed that the presence of nickel in the media had a positive impact on bacterial activity