ZnSe/semi-insulating GaAs interfaces have been studied by observing Photogenerated plasmon – LO (PPL) coupled modes by non-resonant microRaman spectroscopy. The effect of the carriers generated by the focused laser beam was investigated for a series of different thicknesses of ZnSe epitaxial layers. The PPL mode in GaAs is observed in micro-Raman spectra for all samples, but with different magn...

My first interest in nuclear magnetic resonance (n.m.r.) spectroscopy began in 1964, when it seemed to me that spectroscopy, and in particular n.m.r., would be a most desirable way to analyse unknowns without smelling everything, or heating with sodium and checking for hydrogen evolution with a match (the classical A-level approach at the time). Unfortunately, I had to wait a couple of years fo...

2-dimethylamino-9-fluorenol and 2-dimethylamino-9(4'dimethylamino)phenyl-9-fiuorenol in polar solvents in the excited state undergo conformation changes in which two fluorescent isomers are created. The isomers (in the local excited (LE) and charge transfer (CT) configuration) possess separate fluorescence bands, one appearing from the S! (LE) state and the second f rom the intramolecular charg...

Study of genetic material allows the comprehension the origin of the many biochemical changes that follow diseases, like cancer, promoting the development of early preventive inquiry and more efficient individual treatments. Raman spectroscopy can be an important tool in DNA study, since it allows probe molecular vibrations of genetic material in a fast way. The present work established a syste...

Polyaniline-fly ash (PANI-FA) composites were prepared by oxidative polymerization of aniline with fly ash in presence of ammonium persulphate (APS). The PANI-FA composites were prepared with different concentrations of fly ash to aniline ratio. The composites, so prepared, were characterized by UV-vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (S...

As of December 2007, radial velocity measurements and planetary transit surveys for nearby stars have already identified more than 250 planets around other stars. These “extrasolar planets” opened a new field of astronomy in the past decade. The discovery of many extrasolar planets have revealed the existence of exotic planets such as “hot Jupiters” and “eccentric planets,” showing the diversit...

Vibrational spectroscopy plays a prominent role in the research and development of polymers. It provides useful information on their chemical, conformational, crystal and morphological structure. The study of elastomers by Raman spectroscopy has been desirable for a long time. It has allowed quantitative work on blends and isomeric elastomers and also the direct study of the rubber vulcanisatio...

A semiconductor is a type of material which has electrical properties in between an insulator and a conductor. A conductor can be thought of as a group of atoms surrounded by a sea of free electrons, which are free to move throughout the material; in contrast, the electrons in an insulator are tightly localized on a specific atom or molecule. In a semiconductor, the electrons are localized as i...

The parent negative ions of 5-chlorouracil, UCl(-) and 5-fluorouracil, UF(-) have been studied using anion photoelectron spectroscopy in order to investigate the electrophilic properties of their corresponding neutral halouracils. The vertical detachment energies (VDE) of these anions and the adiabatic electron affinities (EA) of their neutral molecular counterparts are reported. These results ...