Search results for "Libs"
showing 10 items of 35 documents
Lāzerinducētās sagraušanas spektroskopijas un enerģijas dispersīvās rengenfluoriscences metožu pielietojums zāļu tēju paraugu pētījumos
2022
Lāzerinducētās sagraušanas spektroskopijas un enerģijas dispersīvās rengenfluoriscences metožu pielietojums zāļu tēju paraugu pētījumos. Černiševs R.., darba vadītāji Mg.chem. Bērtiņš M., Dr.sc.ing. Brangule A. Bakalaura darbs, 39 lappuses, 16 attēli, 13 tabulas, 28 literatūras avoti. Latviešu valodā. Darbā tika veikta zinātniskās literatūras izpēte un apkopojums par spektroskopijas metodēm, ko var izmantot ķīmisko elementu kvalitatīvo un kvantitatīvo noteikšanai. Praktiskajā daļā tika veikta zāļu tēju analīze izmantojot rentgenfluoriscences spektroskopiju un lāzerinducētās sagraušanas spektroskopijas metodēm.
Qualitative-portable to quantitative-laboratory LIBS
2012
No abstract
Development of LIBS for online analysis of solid nuclear materials
2015
With the objective to implement a fast, online analysis technique for control of solid metal nuclear materials, laser-induced breakdown spectroscopy (LIBS) technique is developed for quantitative analysis in uranium and plutonium. Since these matrices have a very dense emission spectrum in the UV-Visible range, the Vacuum Ultra-Violet (VUV) spectral range, less rich in lines, is explored. The aim of this thesis is to perform the analytical development of VUV-LIBS for quantitative analysis between 500 and 5000 ppm with an uncertainty of 3%. For that purpose, four steps were defined. First, for practical and safety reasons, it is generally better to perform experiments on surrogate materials.…
Evaluation of Thin Film Microextraction for trace elemental analysis of liquid samples using LIBS detection
2021
An analytical methodology based in the combination of Thin Film Microextraction with Laser-induced Breakdown Spectroscopy (TFME-LIBS) was investigated, for the first time, for detection of Cu, Cr, Ni and Pb in aqueous solutions. In this methodology, the analytes were extracted in a thin film of adsorbent material deposited on a solid support, which was introduced in the sample to analyse. After extraction, the analytes retained in the adsorbent were analysed by LIBS. In order to obtain adsorbent films useful for the microextraction step, two different experimental procedures for film generation, denoted as Drop Casting Deposition and Mould Deposition, were evaluated. In both cases, graphene…
Double Laser LIBS and micro-XRF spectroscopy applied to characterize materials coming from the Greek-Roman theater of Taormina
2009
The laser-induced breakdown spectroscopy (LIBS) is an applied physical technique that has shown, in recent years, its great potential for rapid qualitative analysis of materials. The possibility to implement a portable instrument that perform LIBS analysis makes this technique particularly useful for in situ analysis in the field of cultural heritages. The aim of this work is to compare the results, obtained by LIBS measurements with X-Ray Fluorescence (XRF) ones, on calcareous and refractory materials coming from the Greek-Roman theater of Taormina. Calibration curves for LIBS and XRF were obtained by measuring certified reference materials and using them as standards. LIBS measurements we…
Applicazione Integrata di Tecniche Analitiche per la Caratterizzazione di Pigmenti Storici
2012
Testing a portable laser-induced breakdown spectroscopy system on geological samples.
2012
9 pages; International audience; This paper illustrates the potentialities of a home-made portable LIBS (laser-induced breakdown spectroscopy) instrument in Earth sciences, more particularly in geochemically recognizing (i) tephra layers in lacustrine sediments and (ii) fossilization processes in ammonites. Abundances for selected lines of Al, Ca, Fe, Ti, Ba and Na were determined in lacustrine chalk sediments of the Jura, where the Laacher See Tephra (LST) layer is recorded. A statistical treatment of elemental maps produced from the section of a sedimentary column containing the LST event allows instrumental conditions to be optimized. Accumulating spectra from close shot positions gives …
Comparison of LIBS and micro-XRF measurements on bronze alloys for monitoring plasma effects
2011
The laser-induced breakdown spectroscopy (LIBS) technique is often used as atomic spectroscopic technique for elemental analysis of materials. However, it presents some drawbacks that make an accurate quantitative analysis difficult. Since the plasma properties, such as spatial inhomogeneity and plume stoichiometry strongly depend on the experimental conditions, the measurements are less reproducible. In order to evaluate the measurement fluctuations, we propose to use the more established micro X-Ray fluorescence (μ-XRF) technique for validating LIBS data. In particular, the quantitative data, obtained by varying the laser fluence, the shot numbers and the temporal acquisition parameters, …
Complementarity of the XRF and LIBS analyses in the conservation science: the case studies of the bronze alloys
2011
The present study confirms how the integrated use of non-destructive or micro-destructive spectroscopic techniques are capable to provide a clear response to the investigative needs in the conservation science. In particular, the X-ray fluorescence analysis in association with laser-induced breakdown spectroscopy can be useful for collecting information about chemical composition and elemental stratigraphic distribution of the external layers. The complementarity of these techniques has been tested by analysing bronze samples, made in the laboratory according to binary, ternary and quaternary alloys, typical of Roman archaeometallurgical production and buried for one year. The findings have…