Near-IR emission in Pr(3+)single doped and tunable near-IR emission in Pr3+/Yb3+ codoped tellurite tungstate glasses for broadband optical amplifiers

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPA study of the broadband near-infrared emission in Pr3+ single doped and Pr3+/Yb3+ codoped tellurite-tungstate glasses for optical amplification is presented. In the Pr3+ single doped samples pumped at 474 nm the emission band at 1480 nm presents a FWHM of similar to 140 nm. The Yb3+ addition produces a FWHM broadening up to 155 nm, achieved through the (1)G(4)-H-3(5) transition. The emission spectra when the codoped sample is pumped at 980 nm shows efficient energy transfer from Yb3+ to Pr3+ resulting in an intense Pr3+ emission around 1330 nm. This shows that changing the pump wavelength it is possible to select the D-1(2)-(1)G(4) or the (1)G(4)-H-3(5) transition, displacing the emission band from similar to 1480 to similar to 1330 nm. (C) 2014 Elsevier B.V. All rights reserved.A study of the broadband near-infrared emission in Pr3+ single doped and Pr3+/Yb3+ codoped tellurite-tungstate glasses for optical amplification is presented. In the Pr3+ single doped samples pumped at 474 nm the emission band at 1480 nm presents a FWHM of similar to 140 nm. The Yb3+ addition produces a FWHM broadening up to 155 nm, achieved through the (1)G(4)-H-3(5) transition. The emission spectra when the codoped sample is pumped at 980 nm shows efficient energy transfer from Yb3+ to Pr3+ resulting in an intense Pr3+ emission around 1330 nm. This shows that changing the pump wavelength it is possible to select the D-1(2)-(1)G(4) or the (1)G(4)-H-3(5) transition, displacing the emission band from similar to 1480 to similar to 1330 nm.36610201026CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCNPq [574017/2008]FAPESP [2005/51689-2, 2008/57857-2, 2012/04291-7, 2009/54066-7]574017/20082005/51689-2; 2008/ 57857-2; 2009/54066-7; 2012/04291-7The Authors would like to thank CNPq (INCT/FOTONICOM, grant 574017/2008) and FAPESP (grants 2005/51689-2, 2008/57857-2 and 2012/04291-7) for their financial support; to the "Laboratorio multiusuario de espectroscopia optica avancada" (LMEOA) for the loan of the spectrofluorimeter (FAPESP grant 2009/54066-7); to professor Antonio Medina Neto and Dr. Leandro Herculano for help in some lifetime measurements performed at "Universidade Estadual de Maringa"; and to the professor Hugo Fragnito for the helpful discussions

Effect of enzymatic pretreatment and increasing the organic loading rate of lipid-rich wastewater treated in a hybrid UASB reactor

This study aimed at evaluating the effect of increasing organic loading rates and of enzyme pretreatment on the stability and efficiency of a hybrid upflow anaerobic sludge blanket reactor (UASBh) treating dairy effluent. The UASBh was submitted to the following average organic loading rates (OLR) 0.98 Kg.m(-3).d(-1), 4.58 Kg.m(-3).d(-1), 8.89 Kg.m(-3).d(-1) and 15.73 Kg.m(-3).d(-1), and with the higher value, the reactor was fed with effluent with and without an enzymatic pretreatment to hydrolyze fats. The hydraulic detention time was 24 h, and the temperature was 30 +/- 2 degrees C. The reactor was equipped with a superior foam bed and showed good efficiency and stability until an OLR of 8.89 Kg.m(-3).d(-1). The foam bed was efficient for solid retention and residual volatile acid concentration consumption. The enzymatic pretreatment did not contribute to the process stability, propitiating loss in both biomass and system efficiency. Specific methanogenic activity tests indicated the presence of inhibition after the sludge had been submitted to the pretreated effluent It was concluded that continuous exposure to the hydrolysis products or to the enzyme caused a dramatic drop in the efficiency and stability of the process, and the single exposure of the biomass to this condition did not inhibit methane formation. (C) 2011 Elsevier B.V. All rights reserved