Navegando por Autor "Silva, Fábio de Moraes Vaz da"

Agora exibindo 1 - 3 de 3

Item
Convenient One-Pot Synthesis of N-Substituted 3-Trifluoroacetyl Pyrroles
(2009) Zanatta, Nilo; Wouters, Ana Dionéia; Fantinel, Leonardo; Silva, Fábio de Moraes Vaz da; Barichello, Rosemário; Silva, Pedro Eduardo Almeida da; Soares, Daniela Fernandes Ramos; Bonacorso, Helio Gauze; Martins, Marcos Antonio Pinto
A new one-pot strategy for the synthesis of a series of new N-substituted 3-trifluoroacetyl pyrroles is presented. These compounds were obtained by the reaction of 3-trifluoroacetyl-4,5- dihydrofuran with primary amines, which generated 1,1,1-trifluoro- 3-(2-hydroxyethyl)-4-alkylaminobut-3-en-2-one intermediates. In most cases these intermediates were not stable enough to be isolated. Thus, in the same reaction vessel they were directly submitted to oxidation with PCC (Corey’s reagent) to furnish 1,1,1-trifluoro- 3-(2-ethanal)-4-alkylaminobut-3-en-2-ones, which under reflux underwent intramolecular cyclization to give the desired N-substituted 3-trifluoroacetyl pyrroles, in moderate yields. All of these pyrroles were tested against pan-susceptible Mycobacterium tuberculosis H37Rv and clinical isolates INH- and RMP-resistant strain and some of these compounds showed significant in vitro antimicrobial activity.
Item
Large eddy simulation of turbulent forced convective flows over a pair of circular cylinders with different arrangements
(2012) Santos, Elizaldo Domingues dos; Silva, Fábio de Moraes Vaz da; Acunha Junior, Ivoni Carlos; Galarça, Marcelo Moraes; Isoldi, Liércio André; Rocha, Luiz Alberto Oliveira
The present study presents large eddy simulation (LES) of forced convective heat transfer in transient, twodimensional, incompressible turbulent flows over a pair of cylinders with two different arrangements: 1) with two circular cylinders in tandem (both cylinders are in line with the streamwise direction of the flow, α = 0º) and 2) two side-by-side circular cylinders (where both cylinders are placed transversally to the streamwise direction of the flow, α = 90º). The dynamic Smagorinsky model is employed for the sub-grid treatment. The simulations are based on the finite volume method solution for the conservation equations of mass, momentum and energy. Both simulations are performed with Reynolds and Prandtl numbers of ReD = 22000 and Pr = 0.71, respectively. The results showed that the transient fluid dynamic and thermal patterns are strongly affected by the configuration of circular cylinders. The kind of arrangement led to a difference of nearly 20 % for time-averaged Nusselt number (NuD).
Item
Numerical investigation of turbulent forced convective flows over a pair of circular cylinders
(2012) Santos, Elizaldo Domingues dos; Silva, Fábio de Moraes Vaz da; Acunha Junior, Ivoni Carlos; Galarça, Marcelo Moraes; Isoldi, Liércio André; Rocha, Luiz Alberto Oliveira
The present study presents large eddy simulation (LES) of forced convective heat transfer in transient, two-dimensional, incompressible turbulent flows over a pair of cylinders with two different arrangements: 1) with two circular cylinders in tandem (both cylinders are in line with the streamwise direction of the flow, β = 0º) and 2) two side-by-side circular cylinders (where both cylinders are placed transversally to the streamwise direction of the flow, β = 90º). The dynamic Smagorinsky model is employed for the sub-grid treatment. The simulations are based on the finite volume method solution for the conservation equations of mass, momentum and energy. Both simulations are performed with Reynolds and Prandtl numbers of ReD = 22000 and Pr = 0.71, respectively. The results showed that the transient fluid dynamic and thermal patterns are strongly affected by the configuration of circular cylinders. The kind of arrangement led to a difference of nearly 20 % for time-averaged Nusselt number (NuD).