Biosorption of cadmium (II) and lead (II) from aqueous solution using exopolysaccharide and biomass produced by Colletotrichum sp.

The biosorption of Cd(II) and Pb(II) ions on biomass and exopolysaccharide (EPS) produced by Colletotrichum sp. fungus has been investigated as a function of contact time, initial pH, initial metal ion concentration, and initial adsorbent concentration in a batch system. Adsorption equilibrium was described by Freundlich and Langmuir isotherms. Adsorption was characterized through granulometry, SEM and EDX analysis. Then, studies were performed to regenerate the adsorbent. Biosorption of metals by biomass and EPS were best described by the Langmuir and Freundlich isotherm, respectively. Results of thermodynamic investigations showed that adsorption reactions were spontaneous (ΔG° < 0), exothermal, and mainly physical. The EPS was able to remove 79 and 98% of cadmium and lead, respectively, and the biomass removed 85 and 84% of cadmium and lead, respectively, in a solution with initial concentration 100 mg L-1, and the four adsorption-desorption cycles of all adsorbents showed up with great regenerative capacity and relative stability after these four cycles, the high potential of these biological materials in sorption has been shown. © 2013 Copyright Balaban Desalination Publications.

Missing solution in a Cornell potential

Missing bound-state solutions for fermions in the background of a Cornell potential consisting of a mixed scalar-vector-pseudoscalar coupling is examined. Charge-conjugation operation, degeneracy and localization are discussed. © 2013 Elsevier Inc.

The proposed solution: a response to current realities; draft

Proposicion para la implementacion de un sistema internacional de informacion en poblacion. El marco de referencia esta constituido por 4 principios basicos: servir a los usuarios en el campo de poblacion, aumentar la disponibilidad de informacion, asegurar la distribucion equitativa, transferencia y flujo de la misma y promover la generacion de nueva informacion. Estos propositos descansan en 2 supuestos generales: el sistema de informacion debe ser activo y neutral. La solucion que se propone consiste en el diseno de un sistema: a).global, con verdadero caracter internacional que sirva a todas las regiones y paises; b).descentralizado; c).interdisciplinario ("mission-oriented"), estructurado en torno a areas-problema y objetivos globales vis a vis la estructuracion en torno a disciplinas; d).de amplitud tematica, partiendo de las areas-problema y guardando la mayor neutralidad posible en la seleccion de temas relevantes en el campo de poblacion.

Obtenção e caracterização de filmes de PHB utilizando a técnica de solution blow spinning

Pós-graduação em Ciência dos Materiais - FEIS