Study of lithium ion exchange by two synthetic zeolites: Kinetics and equilibrium.

We examined the exchange of univalent cations (Na+ and H+) retained on two commercially available synthetic zeolites with Li+ ions present in aqueous solutions in contact with the solids with a view to preparing effective controlled-release pharmaceutical forms. The studied zeolites were manufactured by Merck and featured channel diameters of 0.5 (Zeolite 5A, Ref. 1.05705.250, designated Z-05 in this work) and 1.0 nm (Zeolite 13X, Ref. 1.05703.250, designated Z-10 here). The XRD technique revealed that Z-05 possesses an LTA structure derived from that of sodalite and Z-10 a faujasite-type structure. Their exchange capacities were found to be 2.72 and 3.54 meq/g. The Z-Na + Li(+) / Z-Li + Na(+) and Z-H + Li(+) / Z-Li + H(+) ion-exchange processes were found to be reversible and their kinetic laws to obey the equation (-dC/dt) = k(a) x C(n) x (1-theta) - (k(d) x theta), with n = 1 for Z-10 and n = 2 for Z-05. Based on the equilibrium results, the overall processes involve one (with Z-05) or two single ion-exchange processes (with Z-10). In both cases, the equations that govern equilibrium are direct results of the kinetic laws. Thus, the first process-the one with only Z-05-involves the retention of Li+ cations at anionic sites on the outer surface of the solid and their access to the larger pores; the second process-which occurs with Z-10 only-involves the retention of lithium(I) cations within the zeolite channels. In both systems, the exchange with Li+ (from the aqueous solution) is easier than that with H+; this is consistent with our kinetic, equilibrium, and thermodynamic results.

Ternary copper(II) complexes with N-carboxymethyl-l-prolinato(2-) ion and imidazole or creatinine: a comparative study of the interligand interactions influencing the molecular recognition and stability.

The compounds {[Cu(CMP)(Him)].H(2)O}(n) (I) and [Cu(CMP)(crea)H(2)O].3H(2)O (II) were synthesized and characterized by X-ray diffraction, thermal, spectral and magnetic methods (CMP=N-carboxymethyl-;l-prolinato(2-) ion, Him=imidazole and crea=creatinine). Appropriate structural comparison with other compounds such as {[Cu(CMP)(H(2)O)].H(2)O}(n), [Cu(crea)(2)Cl(2)] and [Cu(dipeptide)(crea)(H(2)O)(x)].nH(2)O (x=0 or 1) have been made in order to prove that crea can act as an imidazole-like ligand (because it is able to promote the same fac- to mer-CMP tridentate conformational change in copper(II) complexes) as well as to discuss the interligand interactions which control the 'Cu(CMP) complex-crea, molecular recognition processes. In contrast to that found in related ternary complexes, we have concluded that direct CMP-crea interligand interactions are missing in the Cu-CMP-crea complex due to the inappropriate correspondence between the donor and/or acceptor H-bonding properties of these ligands. CMP can only act as H-acceptor by its two terminal carboxylate group, and crea can display H-donor and H-acceptor roles by its exocyclic -NH(2) and O moieties, respectively. That promotes the reinforcement of the Cu-N(crea) bond by a bridge -N-H(crea)...O(aqua) (2.867(3)A, 176.4 degrees).

Lithium adsorption by acid and sodium amberlite.

In this paper we used a previously reported model for examining the adsorption of nonelectrolytes in solution by solid adsorbents to study the adsorption of lithium(I) cations by acid and sodium amberlites, which is an ion-exchange process. Based on the results, both are equilibrium processes and obey a kinetic law with a unity partial order in the Li+ concentration. The kinetic results were used to calculate the specific rate constants and thermodynamic activation functions involved. Also, equilibrium isotherms were used to determine the corresponding ion-exchange capacities, the individual equilibrium constants, and the thermodynamic functions for the overall process.

Diseño de un mapa de competencias para el grado de Licenciado en Farmacia / Designing a competency map for the degree of Pharmacy

El perfil propio de cada centro tanto desde el punto de vista académico, como profesional, vienemarcado por la claridad de las competencias genéricas y especificas que han de alcanzar sus titulados.La dificultad de la gestión transversal del mapa de competencias de una titulación reside, entre otras,en la necesidad de que cada competencia se ha de servir desde una o más asignaturas y cada asignaturaha de servir a una o más competencias. El objetivo del presente trabajo consiste en sintetizar elproceso de definición e implementación de las competencias de la titulación del Grado en Farmacia,teniendo en cuenta que éstas se han de adecuar, permanentemente, a las demandas sociales, a losrequisitos de calidad de la formación universitaria y a la mejora continua de sus procesos en el marcodel Espacio Europeo de Educación Superior (EEES) y de la legislación vigente. Se especifican lascapacidades, habilidades, valores y actitudes personales, a nivel de organización y técnicas a corto,medio y largo plazo, que facultan a los titulados para llevar a cabo las funciones propias de susestudios y que los capacita para el pleno desarrollo de su ejercicio profesional(AU)