81. Trace detection of C2H2 in ambient air using continuous wave cavity ring-down spectroscopy combined with sample pre-concentrationManik Pradhan, Ruth Lindley, Roberto Grilli, Iain R. White, Damien Martin, Orr-Ewing Andrew, 2008, izvirni znanstveni članek Opis: Continuous wave cavity ring-down spectroscopy (cw-CRDS) coupled with sample pre-concentration has been used to measure acetylene (C2H2) mixing ratios in ambient air. Measurements were made in the near-infrared region (λ∼1535.393 nm), using the P(17) rotational line of the (ν1+ν3) vibrational combination band, a region free from interference by overlapping spectral absorption features of other air constituents. The spectrometer is shown to be capable of fast, quantitative and precise C2H2 mixing ratio determinations without the need for gas chromatographic (GC) separation. The current detection limit of the spectrometer following sample pre-concentration is estimated to be 35 parts per trillion by volume (pptv), which is sufficient for direct atmospheric detection of C2H2 at concentrations typical of both urban and rural environments. The CRDS apparatus performance was compared with an instrument using GC separation and flame ionization detection (GC-FID); both techniques were used to analyze air samples collected within and outside the laboratory. These measurements were shown to be in quantitative agreement. The indoor air sample was found to contain C2H2 at a mixing ratio of 3.87±0.22 ppbv (3.90±0.23 ppbv by GC-FID), and the C2H2 fractions in the outside air samples collected on two separate days from urban locations were 1.83±0.20 and 0.69±0.14 ppbv (1.18±0.09 and 0.60±0.04 ppbv by GC-FID). The discrepancy in the first outdoor air sample is attributed to degradation over a 2-month interval between the cw-CRDS and GC-FID analyses.
Ključne besede: Rotational Line, Cavity Enhance Absorption Spectroscopy, Adsorbent Trap, Trace Atmospheric Constituent, CRDS Instrument
Objavljeno v RUNG: 15.07.2019; Ogledov: 4065; Prenosov: 0
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82. v-P2O5 micro-clustering in P-doped silica studied by a first-principles Raman investigationLuigi Giacomazzi, Layla Martin-Samos, Antonino Alessi, A. Boukenter, Youcef Ouerdane, Sylvain Girard, Nicolas Richard, Matjaž Valant, Stefano de Gironcoli, 2019, izvirni znanstveni članek Ključne besede: silica, POHC, optical fibers, Raman, EPR
Objavljeno v RUNG: 10.05.2019; Ogledov: 4279; Prenosov: 0
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83. Overview of radiation induced point defects in silica-based optical fibersSylvain Girard, Antonino Alessi, Vincenzo De Michele, Youcef Ouerdane, A. Boukenter, Adriana Morana, Nicolas Richard, Philippe Paillet, Marco Cannas, Simonpietro Agnello, Imène Reghioua, Blaz Winkler, Layla Martin-Samos, Luigi Giacomazzi, Diego Di Francesca, Thierry Robin, 2019, pregledni znanstveni članek Ključne besede: optical fibers, point defects, radiation-induced attenuation, GLPC, NBOHC, STH, ODC, P-doping, Ge-doping, Al-doping
Objavljeno v RUNG: 09.05.2019; Ogledov: 4175; Prenosov: 0
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85. Radiation Effects on Optical Fibers and Fiber-Based SensorsSylvain Girard, A. Boukenter, Youcef Ouerdane, Nicolas Richard, Philippe Paillet, Layla Martin-Samos, Luigi Giacomazzi, Claude Marcandella, 2015, samostojni znanstveni sestavek ali poglavje v monografski publikaciji Ključne besede: Optical Fibers, radiation-induced point defects, dosimetry, ab-initio
Objavljeno v RUNG: 24.10.2018; Ogledov: 4697; Prenosov: 0
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88. Photoactivated processes in optical fibers: generation and conversion mechanisms of twofold coordinated Si and Ge atomsLuigi Giacomazzi, Layla Martin-Samos, A. Boukenter, Youcef Ouerdane, Sylvain Girard, Antonino Alessi, Stefano De Gironcoli, Nicolas Richard, 2017, izvirni znanstveni članek Ključne besede: ODC(II), silica, color centers, first-principles, twofold Si, GLPC
Objavljeno v RUNG: 15.10.2018; Ogledov: 4340; Prenosov: 0
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89. EPR parameters of E' centers in v-SiO2 from first-principles calculationsLuigi Giacomazzi, Layla Martin-Samos, A. Boukenter, Youcef Ouerdane, Sylvain Girard, Nicolas Richard, 2014, izvirni znanstveni članek Ključne besede: silica, paramagnetic defects, EPR, disordered semiconductors
Objavljeno v RUNG: 03.10.2018; Ogledov: 4753; Prenosov: 0
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90. Neutron irradiation effects on the structural properties of KU1, KS-4V and I301 silica glassesM. León, Luigi Giacomazzi, Sylvain Girard, Nicolas Richard, P. Martín, Layla Martin-Samos, A. Ibarra, A. Boukenter, Youcef Ouerdane, 2014, izvirni znanstveni članek Ključne besede: silica, defects, optical fibers, hardening
Objavljeno v RUNG: 03.10.2018; Ogledov: 4781; Prenosov: 0
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