Dependence on the Lens-to-Target Distance and with the Laser Energy at Constant Irradiance of the Laser-Induced Breakdown Spectroscopy Signal.

The emission signal-to-noise ratio (S/N) of a laser-produced plasma on an aluminum target at different focusing distances and at fixed irradiances was investigated. The plasma was produced by a 1064 nm nanosecond-pulsed laser and the energy and irradiances were varied in the 6-110 mJ and 0.4-700 GW cm ranges, respectively.

Characterization of Pottery from Teotihuacan Using Laser-Induced Breakdown Spectroscopy and Inductively Coupled Plasma Optical Emission Spectroscopy.

Pottery sherds from Teotihuacan, Mexico, belonging to the Formative and Classic periods (150 BCE-700 CE) were investigated using laser-induced breakdown spectroscopy (LIBS) and inductively coupled plasma optical emission spectrometry (ICP-OES). LIBS results show that most of the investigated samples have primarily the same elemental composition. Nevertheless, there are also a few sherds that could be associated to foreign ceramic groups with characteristic concentrations of Na, K, Ca, Mn, Rb, and Sr.

Morphological, Optical and Electrical Characterization of the Interfaces in Fullerene-Porphyrin Thin Films.

The role of the interfaces on the optoelectronical properties of porphyrin-fullerene composites has been studied by means of ultraviolet-visible (UV-Vis) and Raman spectroscopy, atomic force microscopy (AFM) and electric conductivity measurements. A simple method of synthesis of donor- acceptor complexes has been performed by subsequent deposition of C fullerene and tetraphenylporphyrin (H₂TPP) thin films, using physical vapor deposition (PVD) on a (100) silicon substrate. UV-Vis spectra showed that the interaction of -orbitals leads to a more ordering for the dipole moments arrangement and the -orbitals overlapping between C and H₂TPP molecules.

Removal of aqueous chromium and environmental CO by using photocatalytic TiO doped with tungsten.

Removal of hexavalent chromium was accomplished by using photocatalyst materials of TiO doped with tungsten oxide, environmental air as oxygen supply and white light as irradiation source. Dichromate anions in concentration ranges of 50 to 1000 μg/L were removed by means of aqueous dispersions of TiO doped with tungsten. The aqueous chromium analyses were performed by Differential Pulse Voltammetry technique.

Chemical elemental analysis of single acoustic-levitated water droplets by laser-induced breakdown spectroscopy.

Laser-induced breakdown spectroscopy is presented for trace element detection of liquid samples by analyzing a single droplet levitated by ultrasonic waves. A single liquid droplet is placed in the node of a standing acoustic wave produced by a uniaxial levitator for further chemical analysis. The acoustic levitator consists of a commercial Langevin-type transducer, attached to a concave mechanical amplifier, and a concave reflector.