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11.
Prosodic marking of information status in L2 intonation
Cinzia Avesani, Giuliano Bocci, Mario Vayra, Alessandra Zappoli, unpublished conference contribution

Keywords: Prosody, Information Status, L2 intonation, Deaccentuation, German, Italian, L2 Acquisition
Published in RUNG: 14.12.2021; Views: 1618; Downloads: 0
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Anaerobic treatment of excess yeast and waste ethanol from alcohol free beer production for increase of renewable energy use in brewing industry
Gregor Drago Zupančič, Mario Panjicko, Goran Lukić, 2020, published scientific conference contribution

Abstract: In the presented paper we have investigated how large quantities of excess yeast and periodical releases of waste ethanol influence the operation of the anaerobic treatment process in a UASB reactor. The process was tested in a pilot-scale reactor with a design organic load of 16.0 kg/m3/day of COD. Through various stages of the experiment, several possible scenarios were tested, excess yeast was added continuously with concentrations up to 3 vol. %, whereas waste ethanol was added in batches of up to 0.8 % of daily volume load several days a week. The intent was to test real conditions in the treatment process. The whole experiment lasted for 77 days, where the maximum organic load of 24.72 kg/m3/day was successfully achieved with no adverse effects on the efficiency of the reactor performance although it significantly surpassed the design load. The COD efficiency at maximum OLR was 83.1 %, whereas the average was 88.0 %. The average biogas production rate increased from 2,044 m3/m3/day to 4.927 m3/m3/day. The microbial community structure analysis showed significant shifts only in the archaeal community (25 – 30 %) as a good adaptation to the addition of substrates. Monitoring the model brewery in applying the addition of yeast and ethanol to the wastewater treatment showed a 110 % increase in biomethane production. The consequence of the increased biomethane production is that the natural gas substitute ratio could be increased from the current average of 10.7 % to potentially 20.1 %, which is a substantial step towards the goal of renewable energy use.
Keywords: anaerobic digestion, biogas, brewery yeast, renewable energy, waste ethanol
Published in RUNG: 10.06.2021; Views: 2530; Downloads: 11
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Sources and transformations of particle-bound polycyclic aromatic hydrocarbons in Mexico City
L. C. Marr, Katja Džepina, Jose L. Jimenez, F. Reisen, H. L. Bethel, Janet Arey, J. S. Gaffney, N. A. Marley, Luisa T. Molina, Mario J. Molina, 2006, original scientific article

Abstract: Understanding sources, concentrations, and transformations of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere is important because of their potent mutagenicity and carcinogenicity. The measurement of particle-bound PAHs by three different methods during the Mexico City Metropolitan Area field campaign in April 2003 presents a unique opportunity for characterization of these compounds and intercomparison of the methods. The three methods are ( 1) collection and analysis of bulk samples for time-integrated gas- and particle-phase speciation by gas chromatography/ mass spectrometry; ( 2) aerosol photoionization for fast detection of PAHs on particles' surfaces; and ( 3) aerosol mass spectrometry for fast analysis of size and chemical composition. This research represents the first time aerosol mass spectrometry has been used to measure ambient PAH concentrations and the first time that fast, real-time methods have been used to quantify PAHs alongside traditional filter-based measurements in an extended field campaign. Speciated PAH measurements suggest that motor vehicles and garbage and wood burning are important sources in Mexico City. The diurnal concentration patterns captured by aerosol photoionization and aerosol mass spectrometry are generally consistent. Ambient concentrations of particle-phase PAHs typically peak at similar to 110 ng m(-3) during the morning rush hour and rapidly decay due to changes in source activity patterns and dilution as the boundary layer rises, although surface-bound PAH concentrations decay faster. The more rapid decrease in surface versus bulk PAH concentrations during the late morning suggests that freshly emitted combustion-related particles are quickly coated by secondary aerosol material in Mexico City's atmosphere and may also be transformed by heterogeneous reactions.
Keywords: aerosol mass-spectrometer, aerodynamic diameter measurements, oxygenated organic aerosols, relative rate constants
Published in RUNG: 12.04.2021; Views: 2224; Downloads: 0
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Detection of particle-phase polycyclic aromatic hydrocarbons in Mexico City using an aerosol mass spectrometer
Katja Džepina, Janet Arey, Linsey C. Marr, D. Worsnop, Dara Salcedo, Q. Zhang, Timothy B. Onasch, Luisa T. Molina, Mario J. Molina, Jose L. Jimenez, 2007, original scientific article

Abstract: We report the quantification of ambient particle-bound polycyclic aromatic hydrocarbons (PAHs) for the first time using a real-time aerosol mass spectrometer. These measurements were carried out during the Mexico City Metropolitan Area field study (MCMA-2003) that took place from March 29 to May 4, 2003. This was the first time that two different fast, real-time methods have been used to quantify PAHs alongside traditional filter-based measurements in an extended field campaign. This paper focuses on the technical aspects of PAH detection in ambient air with the Aerodyne AMS equipped with a quadrupole mass analyzer (Q-AMS), on the comparison of PAHs measured by the Q-AMS to those measured with the other two techniques, and on some features of the ambient results. PAHs are very resistant to fragmentation after ionization. Based on laboratory experiments with eight PAH standards, we show that their molecular ions, which for most particulate PAHs in ambient particles are larger than 200 amu, are often the largest peak in their Q-AMS spectra. Q-AMS spectra of PAH are similar to those in the NIST database, albeit with more fragmentation. We have developed a subtraction method that allows the removal of the contribution from non-PAH organics to the ion signals of the PAHs in ambient data. We report the mass concentrations of all individual groups of PAHs with molecular weights of 202, 216, 226 + 228, 240 + 242, 250 + 252, 264 + 266, 276 + 278, 288 + 290, 300 + 302, 316 and 326 + 328, as well as their sum as the total PAH mass concentration. The time series of the Photoelectric Aerosol Sensor (PAS) and Q-AMS PAH measurements during MCMA-2003 are well correlated, with the smallest difference between measured PAH concentrations observed in the mornings when ambient aerosols loadings are dominated by fresh traffic emissions. The Q-AMS PAH measurements are also compared to those from GC–MS analysis of filter samples. Several groups of PAHs show agreement within the uncertainties, while the Q-AMS measurements are larger than the GC–MS ones for several others. In the ambient Q-AMS measurements the presence of ions tentatively attributed to cyclopenta[cd]pyrene and dicyclopentapyrenes causes signals at m/z 226 and 250, which are significantly stronger than the signals in GC–MS analysis of filter samples. This suggests that very labile, but likely toxic, PAHs were present in the MCMA atmosphere that decayed rapidly due to reaction during filter sampling, and this may explain at least some of the differences between the Q-AMS and GC–MS measurements.
Keywords: AMS, PAH, Mexico City
Published in RUNG: 11.04.2021; Views: 2943; Downloads: 0
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18.
Comparative Analysis of urban atmospheric aerosol by particle-induced X-ray emission (PIXE), proton elastic scattering analysis (PESA), and aerosol mass spectrometry (AMS)
K.S. Johnson, A. Laskin, Jose L. Jimenez, V. Shutthanandan, Luisa T. Molina, Dara Salcedo, Katja Džepina, Mario J. Molina, 2008, original scientific article

Abstract: A multifaceted approach to atmospheric aerosol analysis is often desirable infield studies where an understanding of technical comparability among different measurement techniques is essential. Herein, we report quantitative intercomparisons of particle-induced X-ray emission (PIXE) and proton elastic scattering analysis (PESA), performed offline under a vacuum, with analysis by aerosol mass spectrometry (AMS) carried out in real-time during the MCMA-2003 Field Campaign in the Mexico City Metropolitan Area. Good agreement was observed for mass concentrations of PIXE-measured sulfur (assuming it was dominated by SO42-) and AMS-measured sulfate during most of the campaign. PESA-measured hydrogen mass was separated into sulfate H and organic H mass fractions, assuming the only major contributions were (NH4)(2)SO4 and organic compounds. Comparison of the organic H mass with AMS organic aerosol measurements indicates that about 75% of the mass of these species evaporated under a vacuum. However similar to 25% of the organics does remain under a vacuum, which is only possible with low-vapor-pressure compounds, and which supports the presence of high-molecular-weight or highly oxidized organics consistent with atmospheric aging. Approximately 10% of the chloride detected by AMS was measured by PIXE, possibly in the form of metal-chloride complexes, while the majority of Cl was likely present as more volatile species including NH4Cl. This is the first comparison of PIXE/PESA and AMS and, to our knowledge, also the first report of PESA hydrogen measurements for urban organic aerosols.
Keywords: organic aerosols, secondary organic aerosols, Mexico City, MCMA-2003 field campaign
Published in RUNG: 11.04.2021; Views: 2244; Downloads: 0
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19.
Projekt za izvedbo izvedbo inženiringa in kontrolo pri dodajanju velike količine pivovarniškega kvasa in alkohola-etanola v Biobed® reaktor
Goran Lukić, Matej Markulin, Gregor Drago Zupančič, Mario Panjicko, project documentation (preliminary design, working design)

Keywords: Anaerobna digestija, Bioplin, kvas, etanol
Published in RUNG: 04.12.2020; Views: 2510; Downloads: 0
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20.
Anaerobic Co-Digestion of Ligno-Cellulosic degradation products - Wood Resin Residue from Tannin Production
Gregor Draago Zupančič, Mario Panjicko, Domagoj Eršek, Goran Lukić, Žiga Velišček, Martin Gojun, 2018, published scientific conference contribution

Abstract: Tannin is a very versatile industrial material used for many applications. During tannin production, a residue is produced, which consists of 10 – 15 % sodium acetate solution with up to 10 % water-soluble wood resins by mass. Since it contains a high portion of acetate, it can be useful for anaerobic digestion to produce biomethane, whereas wood resins may exhibit inhibitory effects. In order to test the biodegradability of wood resin residue, several batch tests were performed with two approaches. In the first approach, co-digestion with corn-silage and animal waste was performed utilizing suspended biomass inoculum. In the second approach, co-digestion with pulp and paper wastewater was performed utilizing granular biomass inoculum. In the first approach, the results showed partial inhibition of degradation using mixtures of 25.6 % and total inhibition using 100.0 % of wood resin. Maximum biodegradability achieved was 83.4 %. In the second approach, the results showed partial inhibition of degradation using mixtures of 1.7 and 3.3 % of wood resin. Maximum biodegradability achieved was 64.3 %. Because the second approach enabled us to process larger quantities of wood resin (larger COD load), a pilot experiment of anaerobic co-digestion with pulp and paper wastewater was performed, utilising similar conditions to the considered full-scale treatment. The results showed COD degradation between 70.1 and 81.7 % and a potential increase in total produced biomethane of 36 – 39 %, with no significant adverse effects. Wood resin residue yielded 45 – 50 m3 of biomethane per tonne, which exhibits a good potential for biomethane production. If used for biomethane production in pulp and paper wastewater treatment, the valorisation value of the wood resin residue is between 54,500 € and 94,000 €, which makes the presented treatment also an economically viable option.
Keywords: Anaerobic digestion, biomethane production, wood resin residue
Published in RUNG: 11.03.2020; Views: 3202; Downloads: 0
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