Search results for "Spectroscopy"
showing 10 items of 10293 documents
Impact of buffer gas quenching on the $^1S_0$ $\to$ $^1P_1$ ground-state atomic transition in nobelium
2017
International audience; Using the sensitive Radiation Detected Resonance Ionization Spectroscopy (RADRIS) techniquean optical transition in neutral nobelium (No, Z = 102) was identified. A remnant signal when delaying the ionizing laser indicated the influence of a strong buffer gas induced de-excitation of the optically populated level. A subsequent investigation of the chemical homologue, ytterbium (Yb, Z = 70), enabled a detailed study of the atomic levels involved in this process, leading to the development of a rate equation model. This paves the way for characterizing resonance ionization spectroscopy (RIS) schemes used in the studyof nobelium and beyond, where atomic properties are c…
Synthesis of Yb nanoparticles by laser ablation of ytterbium target in sodium bis(2-ethylhexyl)sulfosuccinate reverse micellar solution
2010
Abstract Surfactant-coated ytterbium nanoparticles were produced by Nd:YAG laser ablation of a Yb bulk target immersed in sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/ n -heptane micellar solution. In our experimental conditions, as highlighted by IR spectroscopy, AOT molecules are not decomposed by the intense laser pulses but play a pivotal role in the stabilisation of Yb nanoparticles. The formation of Yb nanoparticles in the liquid phase was monitored by UV–Vis spectroscopy whereas the Yb/AOT composites obtained by evaporation of the organic solvent were characterised by XPS and TEM. Data analysis consistently shows the presence of surfactant-coated, nearly spherical and non-interacting…
Sulfur Dioxide Oxidation Catalyzed by Photosensitized Ytterbium Diphthalocyanine
2008
Oxidation of SO2 into SO3 was found effectively catalyzed by photosensitized ytterbium diphthalocyanine, YbPc2 (Pc = phthalocyanine ligand, C32H16N8) when performed in air-saturated dimethylformamide (DMF) solution at 20 °C. The process follows according to a multi-step complex mechanism involving chemical induction as its driving force. Excitation energy of the sandwich molecular system in YbPc2 is used to promote the reaction by creating a reactive intermediate form of the ytterbium complex hosting up to eight SO2 molecules. The conversion of SO2 proved complete.
Luminescence properties of zirconia nanocrystals prepared by solar physical vapor deposition
2014
Abstract Zirconia nanocrystals have attracted considerable interest as biolabels, which can be used as probes for medical imaging and biosensor applications. However, zirconia particle agglomeration forms a major limitation to its use for biolabeling. In this backdrop, for the first time, well-separated zirconia nanocrystals were obtained in a Heliotron reactor (PROMES CNRS, France) via the solar physical vapor deposition (SPVD) method. As the raw material target for solar evaporation, zirconia nanopowders obtained via the sol–gel process were used. The luminescence and upconversion luminescence properties of the Sol Gel nanopowders were compared with those of the SPVD nanocrystals. Erbium …
Optical diagnostic method for benzene detection in air
2014
In this paper we show our first results of research for creation a detector for benzene vapor and possibly other volatile organic compounds detection in air based on Zeeman atomic absorption technique. First the detailed study of benzene absorption spectra with high resolution spectrometer Jobin-Yvon 1000M was done. The absorption spectra of benzene were registered in the spectral range from 200-900 nm. More detailed analysis was done for the 240 – 260 nm spectral range to test a possibility to detect benzene by means of emission line of 254 nm of mercury.
Critical review of the atomic spectrometric analysis of arsenic in foods
1994
The literature on the determination of arsenic in foods by atomic spectroscopy involving hydride generation, platform furnace Zeeman and inductively coupled plasma has been critically reviewed. Hydride generation has been largely displaced as a powerful tool by platform furnace Zeeman, using the STPF (stabilized temperature platform furnace) concept for the control of interferences. Inductively coupled plasma with conventional pneumatic nebulization has been little used. An alternative is to employ hydride generation-ICP with extraction of the arsenic in an organic phase. This technique permits proper control of interferences together with an increase in sensitivity. Depending on the conten…
<title>Deconvolution of the mercury 253.7 nm spectral line shape for the use in absorption spectroscopy</title>
2008
In this work we present measurement and results of the deconvolution of the Hg 253.7 nm spectral line shapes, emitted from the mercury isotope high-frequency electrodeless discharge lamps, made at the Institute of Atomic Physics and Spectroscopy for the use in Zeeman Atomic Absorption Spectrometry. The emission line profiles of 254 nm Hg resonance line have been measured by means of a Zeeman scanning spectrometer at the mercury cold spot temperature value at 20 C. Then the deconvolution procedure or solving of this ill-posed inverse problem by means of the Tikhonov's regularization method [1] was performed to obtain the real spectral line shape.© (2008) COPYRIGHT SPIE--The International Soc…
<title>Advanced light sources for atomic absorption analysis</title>
2003
High-frequency electrodeless light sources (HF EDLS) are widely used as bright radiators of narrow and intensive atomic and ionic spectral lines, covering the spectrum from VUV to IR. Main characteristics of HF EDLS are high emitted spectral line intensity, long service life, and in general, narrow spectral line shapes because of low-pressure of filling elements. In this work we give a short overview of the use of HF EDLS, containing Hg, Te, Se, Zn, Pb, As, Sb, Bi, Tl, In, Cd, Sn, in Zeeman Atomic absorption devices for assaying natural, drinking, waste and technical water as well as air, soil, food products and biological samples. The first steps are made for optimization of Ge, Ga, P, S, …
High-Pressure Raman Study of Zincblende, Cinnabar, and Cmcm Phases Of ZnTe
2002
Raman measurements of ZnTe have been performed at pressures up to 15 GPa. Frequencies, line widths, and intensities of first- and second-order Raman features of the zincblende phase (0-9.5 GPa) were studied in detail. In this note, we focus on the Raman spectra of the high-pressure cinnabar and Cmcm phases. In the transition regime from cinnabar to Cmcm (12.2 to 13.7 GPa) the Raman data indicate the possible existence of a new intermediate high-pressure phase.
Determination at low ppm levels of dithiocarbamate residues in foodstuff by vapour phase-liquid phase microextraction-infrared spectroscopy
2010
Abstract A methodology based on the vapour phase (VP) generation of carbon disulphide from non-volatile dithiocarbamate compounds has been developed for determination of pesticide residues in foodstuff at low ppm levels. The method involves a selective reaction combined with liquid phase microextraction (LPME) and transmission infrared measurements. The use of a home made transmission cell improved the detection limits (LOD) compared to the use of attenuated total reflectance measurements by a factor of approximately 80. Using the most appropriate experimental conditions for the CS2 generation and LPME preconcentration, the precision of the methodology, expressed as the relative standard de…