Encontrados 6 documentos, a visualizar página 1 de 1
Multi-pumping mechanised determination of selenium in natural waters by light e...
Fernandes,Ridvan N.; Reis,Boaventura F.; Morales-Rubio,Angel; de la Guardia,MiguelIt has been developed a fully mechanised procedure for the determination of selenium in waters employing a LED based spectrometer and solenoid multi-pumps as solution propelling devices. The proposed method is based on the reaction of selenium with potassium iodide in an acidic medium to liberate iodine, which oxidizes Variamine Blue to form a violet-colour species which absorb at 530 nm. The system was mechani...
The challenge of predicting optical properties of biomolecules: what can we lea...
Castro, Alberto; Marques, Miguel A. L.; Varsano, Daniele; Sottile, Francesco; Rubio, Angelhttp://www.sciencedirect.com/science/article/B6X19-4V2X6RJ-3/2/1e93da040f6f28c5c62005f2523855af
A chemiluminescence flow-based procedure for determination of carbaryl in natur...
Pires,Cherrine K.; Morales-Rubio,Angel; de la Guardia,Miguel; Lima,José L. F. C.; Zagatto,Elias A. G.; Reis,Boaventura F.A chemiluminescence procedure for the determination of carbaryl in natural waters using acetylcholinesterase and choline oxidase is described. The flow system designed to implement multicommutation approach controlled by microcomputer comprised five solenoid valves, two columns with immobilized enzymes on controlled pore glass beads and chemiluminometric flow cell. In the best experimental conditions a linear r...
A TDDFT Study of the Excited States of DNA Bases and Their Assemblies
Varsano, Daniele; Felice, Rosa Di; Marques, Miguel A. L.; Rubio, AngelWe present a detailed study of the optical absorption spectra of DNA bases and base pairs, carried out by means of time dependent density functional theory. The spectra for the isolated bases are compared to available theoretical and experimental data and used to assess the accuracy of the method and the quality of the exchange-correlation functional. Our approach turns out to be a reliable tool to describe the...
Octopus: a tool for the application of time-dependent density functional theory
Castro, Alberto; Appel, Heiko; Oliveira, Micael; Rozzi, Carlo A.; Andrade, Xavier; Lorenzen, Florian; Marques, M. A. L.; Gross, E. K. U.; Rubio, AngelWe report on the background, current status, and current lines of development of the octopus project. This program materializes the main equations of density-functional theory in the ground state, and of time-dependent density-functional theory for dynamical effects. The focus is nowadays placed on the optical (i.e. electronic) linear response properties of nanostructures and biomolecules, and on the non-linear...
Transferability of a local pseudopotential based on solid-state electron density
Nogueira, Fernando; Fiolhais, Carlos; He, Jingsong; Perdew, John P.; Rubio, AngelLocal electron - ion pseudopotentials fitted to dominant density parameters of the solid state (valence, equilibrium average electron density and interstitial electron density) have been constructed and tested for sixteen simple metals. Calculated solid-state properties present little evidence of the need for pseudopotential non-locality, but this need is increasingly evident as the pseudopotentials are transfe...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||