A new selective technique for characterization of polycyclic aromatic hydrocarbons in complex samples: UV resonance Raman spectrometry of coal liquids.
Evidence is given showing that UV resonance Raman spectroscopy (UVRRS) is a powerful technique for the identification and quantitation of polycyclic aromatic hydrocarbons (PAH's) in a coal liquid. Results suggest that this technique will be of general utility for the study of systems containing chromaphoric species absorbing in the UV spectral region. In this paper it is demonstrated that (1) the resonance Raman spectra of PAH derivatives can be selectively observed in solutions of coal liquids and (2) different UV excitation wavelengths result in the selective Raman enhancement of different polycyclic aromatic hydrocarbon ring systems.
Development of a new UV resonance Raman spectrometer for the 217–400‐nm spectral region
The design and construction of a new UV resonance Raman spectrometer continuously tunable between 217–750 nm are described. The excitation source is based on a YAG laser which is frequency doubled or tripled to pump a dye laser. UV light is generated by nonlinear frequency doubling and mixing of the dye laser output or doubled output with the 1.06‐μm YAG fundamental. The detection system utilizes an intensified Reticon multichannel array. Commercially available monochromators are modified to make them useful for UV resonance Raman spectroscopy. Some sampling methodologies important for UV resonance Raman measurements are described. Examples of the sensitivity of UV resonance Raman spectroscopy are illustrated.
EL TRATAMIENTO NEOPRAGMATISTA DE LA VERDAD EN RICHARD RORTY NEOPRAGMATIST TREATMENT OF TRUTH IN RICHARD RORTY
Richard Rorty, one of the most influential authors of our time, presents a critique of the philosophical concept of truth as correspondence. The conclusion of Rorty's neopragmatism is that the idea of truth as correspondence between language and facts is ineffective because it no longer works. The neopragmatist conception of truth indicates the only possible uses for the term «truthful,» revolving around the idea of jus - tification. In this article, the neopragmatist notion of truth is presented in order to