3531. Implementation of liquid chromatography coupled to thermal lens spectrometry (HPLC-TLC) in studies of yeats' role in formation of stable pigments in Pinot Noir winesBranka Mozetič Vodopivec, Jelena Topić, Lorena Butinar, Natka Ćurko, Karin Kovačević Ganić, Dorota Korte, Mladen Franko, 2019, published scientific conference contribution abstract Keywords: thermal lens spectrometry, pigments, Pinot Noir wines
Published in RUNG: 16.07.2019; Views: 3562; Downloads: 0
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3533. Determination of bioavailable Fe redox fractions of sediment pore waters by DGT passive sampling and BDS detectionHanna Budasheva, Dorota Korte, Arne Bratkič, Mladen Franko, 2019, published scientific conference contribution abstract Abstract: 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.
Keywords: beam deflection spectrometry, diffusive gradients in thin-films, iron species
Published in RUNG: 16.07.2019; Views: 3480; Downloads: 0
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3534. 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, original scientific article Abstract: 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.
Keywords: Rotational Line, Cavity Enhance Absorption Spectroscopy, Adsorbent Trap, Trace Atmospheric Constituent, CRDS Instrument
Published in RUNG: 15.07.2019; Views: 3306; Downloads: 0
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3540. Sodobni pristop k energetski prenovi stavb : Trajnostna gradnjaMarjana Šijanec-Zavrl, Henrik Gjerkeš, Marko Jačimovič, Neva Jejčič, 2018, professional article Abstract: Razvoj trga prenov v stavbnem sektorju se sooča s težavami na celotnem območju Evropske unije, vendar so le te na območju sredozemskih držav nekoliko specifične zaradi okoljskih in klimatskih pogojev, lastniške strukture stanovanjskega sektorja, družbenih in ekonomskih dejavnikov ter posledic gospodarske krize, ki je prizadela večino teh
držav. Mednarodni projekt H2020 HAPPEN je namenjen razvoju in širjenju pristopa h globoki oziroma celoviti prenovi stanovanjskih stavb, posebej prilagojenih za države na območju Sredozemlja. Organizacijske in tehnične rešitve ter oblike financiranja bodo uporabljene tudi na pilotnih primerih, informacije z rezultati pa bodo dostopne preko digitalne platforme.
Keywords: Trajnostna gradnja, energetska učinkovitost, prenova stavb, Happen
Published in RUNG: 12.07.2019; Views: 4151; Downloads: 0
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