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51.
Determination of source specific black carbon and CO2 emission rates by means of 222Rn tracer
Asta Gregorič, Luka Drinovec, Irena Ježek, Janja Vaupotič, Griša Močnik, 2019, objavljeni povzetek znanstvenega prispevka na konferenci

Ključne besede: black carbon emission, radon
Objavljeno: 17.07.2019; Ogledov: 48; Prenosov: 0
.pdf Polno besedilo (13,70 MB)

52.
Evaluation of VOC denuder efficiency and positive artefactdue to denuder breakthrough using TCA08
Asta Gregorič, Gašper Lavrič, Martin Rigler, 2019, objavljeni povzetek znanstvenega prispevka na konferenci

Ključne besede: VOC denuder, TCA08, sampling artefact
Objavljeno: 17.07.2019; Ogledov: 66; Prenosov: 0
.pdf Polno besedilo (6,60 MB)

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Photothermal spectrophotometer for meaurements of low absorption in liquid samples
J. Akbar, Humberto Cabrera, Dorota Korte Kobylinska, 2019, objavljeni povzetek znanstvenega prispevka na konferenci

Ključne besede: photothermal spectroscopy techniques, halogen lamps, TL signal
Objavljeno: 16.07.2019; Ogledov: 75; Prenosov: 0
.pdf Polno besedilo (324,00 KB)

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Determination of bioavailable Fe redox fractions of sediment pore waters by DGT passive sampling and BDS detection
Mladen Franko, Arne Bratkič, Dorota Korte, Hanna Budasheva, 2019, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: The bioavailability and toxicity of contaminants in sediments to benthic organisms depend on the speciation of the contaminant [1]. The level of iron supply to sediments creates contrasting chemical pathways, each producing distinctive mineral assemblag- es. Reliable measurement of Fe redox species (Fe2+ and Fe3+) in sediments is essential for studies of pollutants or trace-element cycling. This is, however, a difficult task, because the distribution of chemical species often changes during sampling and storage. In this work the Diffusive Gradients in Thin-films technique (DGT) is investigated as a passive sampling approach used in combination with photothermal beam deflection spectroscopy (BDS) as a detection method for determination of labile Fe-redox species in sediments and natural waters. DGT offers the advantage of pre-concentration of labile (i.e. bioavailable) Fe species from the total dissolved Fe pool in sediment pore waters [2]. The advantage of using BDS [3-4] is also in avoiding contamination by using additional steps as extraction or pre-concentration. Furthermore, combined DGT-BDS provides 2D information about distribution of Fe2+ and the total Fe content in the resin hydrogels [5]. The goal of this research is to show the repeatability of this technique for determining trace amounts of Fe redox species in environmental samples.
Ključne besede: beam deflection spectrometry, diffusive gradients in thin-films, iron species
Objavljeno: 16.07.2019; Ogledov: 69; Prenosov: 0
.pdf Polno besedilo (29,60 MB)

59.
Trace detection of C2H2 in ambient air using continuous wave cavity ring-down spectroscopy combined with sample pre-concentration
Orr-Ewing Andrew, Damien Martin, Iain White, Roberto Grilli, Ruth Lindley, Manik Pradhan, 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: 15.07.2019; Ogledov: 111; Prenosov: 0
.pdf Polno besedilo (363,50 KB)

60.
Izum brez pompoznih besed
Matjaž Valant, intervju

Ključne besede: shranjevanje energije, energetika, izum
Objavljeno: 12.07.2019; Ogledov: 73; Prenosov: 0
.pdf Polno besedilo (875,04 KB)

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