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The Energy Content of Extensive Air Showers in the Radio Frequency Range of 30-80 MHz
Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Darko Veberič, Marta Trini, Samo Stanič, Ahmed Saleh, Gašper Kukec Mezek, Andrej Filipčič, Christian Glaser, 2015, published scientific conference contribution

Abstract: At the Auger Engineering Radio Array (AERA) of the Pierre Auger Observatory, we have developed a new method to measure the total amount of energy that is transferred from the primary cosmic ray into radio emission. We find that this radiation energy is an estimator of the cosmic ray energy. It scales quadratically with the cosmic ray energy, as expected for coherent emission. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicular to the geomagnetic field at the Auger site, in the frequency band of the detector from 30 to 80 MHz. These observations are compared to the data of the surface detector of the Observatory, which provide well-calibrated energies and arrival directions of the cosmic rays. We find energy resolutions of the radio reconstruction of 22% for the complete data set, and 17% for a high-quality subset containing only events with at least five stations with signal.
Found in: ključnih besedah
Keywords: Pierre Auger Observatory, the Auger Engineering Radio Array (AERA), extensive air showers, radio reconstruction: energy resolution
Published: 03.03.2016; Views: 2897; Downloads: 165
.pdf Fulltext (574,66 KB)

Uranium bearing dissolved organic matter in the porewaters of uranium contaminated lake sediments
Breda Novotnik, Wei Chen, R. Douglas Evans, 2018, original scientific article

Abstract: Uranium (U) mobility in the environment strongly depends on its oxidation state and the presence of complexing agents such as inorganic carbon, phosphates, and dissolved organic matter (DOM). Despite the importance of DOM in U mobility, the exact mechanism is still poorly understood. Therefore, the aim of our investigation was to characterise sediment porewater DOM in two lakes in Ontario, Canada (Bow and Bentley Lakes) that were historically contaminated with U and propose possible composition of UO2-bearing DOM. Depth profiles of U concentrations in porewaters and total sediment digests reveal U levels of up to 1.3 mg L−1 in porewater and up to 0.8 mg−1 g in sediment. Depth profiles of U did not correlate with Fe, Mn, SO4 2−, or Eh profiles. Therefore, porewater DOM was analysed and taken into consideration as the primary source of U mobility. Porewater DOM in each sediment section (1 cm sections, 20 cm core length) was analysed by high-resolution electrospray ionisation mass spectrometry. PCA analyses of porewater DOM mass spectra showed grouping and clear separation of DOM in sediment sections with elevated U concentrations in comparison to sections with background U concentrations. Several criteria were set to characterise UO2-bearing DOM and more than 70 different molecules were found. The vast majority of these UO2-DOM compounds fell in the category of carboxyl-containing aliphatic molecules (H/C between 0.85 and 1.2 and O/C≤0.4) and had a mean value of m/z about 720.
Found in: ključnih besedah
Summary of found: ...20 cm core length) was analysed by high- resolution electrospray ionisation mass spectrometry. PCA analyses of porewater...
Keywords: Uranium Lake sediments Porewater Disolved organic matter High resolution mass spectrometry
Published: 09.10.2019; Views: 1573; Downloads: 0
.pdf Fulltext (1,48 MB)

Alice Avian, 2020, doctoral dissertation

Abstract: Human Papillomavirus (HPV) infection is the causative agent for the invasive cervical cancer and its precancerous lesions, furthermore, there are growing evidences of HPV being a relevant factor in other anogenital cancers as well as head and neck cancers. Most sexually active women become infected with HPV at least once in their lifetime, but less than 10% of women becomes persistently infected, and it is precisely the persistent infection that contributes to the development of cervical cancer. The preventive effect of cervical cancer screening largely depends in the high women participation and coverage; indeed, a large number of cervical cancers diagnoses normally arise among under-screened and unscreened women. Increase in the screening coverage is essential to improve the effectiveness of cervical screening programmes. The main purpose of this PhD project was to solve some of the most relevant problems in the cervical cancer screening programmes, as the increase of cost-effectiveness and the amelioration of the screening coverage. My work was focused on the development and validation of the first Ulisse BioMed S.p.A. product, the HPV Selfy™ test, an innovative PCR-based kit for the direct detection and genotyping of 12 high-risk HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59) and 2 possible/probable high-risk (66 and 68), specifically optimized for the analysis of self-collected vaginal specimens. The core of this innovative test is based on high-resolution melting (HRM) analysis, a recently developed technique for fast, high-throughput post-PCR analysis of variance in nucleic acid sequences, that characterizes the amplicons by studying thermal denaturation of double-stranded DNA. Based on this approach and through the design of different HPV type-specific primer pairs and the development of a specific master mix, unique melting peaks in a single fluorescence channel were obtained, allowing the multiple detection and genotyping of 14 HPV types in a single PCR well. Three different clinical studies have been carried out to validate the assay on the vaginal self-collected samples with truly amazing results regarding the assay’s performance, but also for self-sampling acceptability by women. Moreover, data collected in these studies suggest a future possible use of this test for the hard-to-reach women, as an alternative of the conventional clinician-collected sample, in order to increase the cervical cancer screening coverage.
Found in: ključnih besedah
Summary of found: ...of this innovative test is based on high- resolution melting (HRM) analysis, a recently developed technique...
Keywords: Human Papillomavirus, HPV test, cervical cancer screening, prevention, diagnostic test, High resolution melting, HRM, genotyping, PCR, Self-sampling, clinical validation.
Published: 17.06.2020; Views: 1408; Downloads: 29
.pdf Fulltext (37,88 MB)

Molecular and physical characteristics of aerosol at a remote free troposphere site
Simeon K. Schum, Bo Zhang, Katja Džepina, Paulo Fialho, Claudio Mazzoleni, Lynn R. Mazzoleni, 2018, original scientific article

Abstract: Aerosol properties are transformed by atmospheric processes during long-range transport and play a key role in the Earth’s radiative balance. To understand the molecular and physical characteristics of free tropospheric aerosol, we studied samples collected at the Pico Mountain Observatory in the North Atlantic. The observatory is located in the marine free troposphere at 2225m above sea level, on Pico Island in the Azores archipelago. The site is ideal for the study of long-range-transported free tropospheric aerosol with minimal local influence. Three aerosol samples with elevated organic carbon concentrations were selected for detailed analysis. FLEXPART retroplumes indicated that two of the samples were influenced by North American wildfire emissions transported in the free troposphere and one by North American outflow mainly transported within the marine boundary layer. Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry was used to determine the detailed molecular composition of the samples. Thousands of molecular formulas were assigned to each of the individual samples. On average  60% of the molecular formulas contained only carbon, hydrogen, and oxygen atoms (CHO),  30% contained nitrogen (CHNO), and  10% contained sulfur (CHOS). The molecular formula compositions of the two wildfire-influenced aerosol samples transported mainly in the free troposphere had relatively low average O=C ratios (0:480:13 and 0:450:11) despite the 7–10 days of transport time according to FLEXPART. In contrast, the molecular composition of the North American outflow transported mainly in the boundary layer had a higher average O=C ratio (0:570:17) with 3 days of transport time. To better understand the difference between free tropospheric transport and boundary layer transport, the meteorological conditions along the FLEXPART simulated transport pathways were extracted from the Global Forecast System analysis for the model grids. We used the extracted meteorological conditions and the observed molecular chemistry to predict the relative-humidity-dependent glass transition temperatures (Tg) of the aerosol components. Comparisons of the Tg to the ambient temperature indicated that a majority of the organic aerosol components transported in the free troposphere were more viscous and therefore less susceptible to oxidation than the organic aerosol components transported in the boundary layer. Although the number of observations is limited, the results suggest that biomass burning organic aerosol injected into the free troposphere is more persistent than organic aerosol in the boundary layer having broader implications for aerosol aging.
Found in: ključnih besedah
Summary of found: ...outflow mainly transported within the marine boundary layer. Ultrahigh- resolution Fourier transform ion cyclotron resonance mass spectrometry was...
Keywords: secondary organic aerosols, brown carbon, particle dispersion model, ultrahigh-resolution FT-ICR MS, Pico Mountain Observatory
Published: 10.04.2021; Views: 434; Downloads: 0
.pdf Fulltext (5,35 MB)

Molecular characterization of free tropospheric aerosol collected at the Pico Mountain Observatory
J. Hueber, Sumit Kumar, J. A. Perlinger, Katja Džepina, Claudio Mazzoleni, Paulo Fialho, Swarup China, Bo Zhang, R. Chris Owen, D. Helmig, 2015, original scientific article

Abstract: Free tropospheric aerosol was sampled at the Pico Mountain Observatory located at 2225 m above mean sea level on Pico Island of the Azores archipelago in the North Atlantic. The observatory is located ∼ 3900 km east and downwind of North America, which enables studies of free tropospheric air transported over long distances. Aerosol samples collected on filters from June to October 2012 were analyzed to characterize organic carbon, elemental carbon, and inorganic ions. The average ambient concentration of aerosol was 0.9 ± 0.7 µg m−3 . On average, organic aerosol components represent the largest mass fraction of the total measured aerosol (60 ± 51 %), followed by sulfate (23 ± 28 %), nitrate (13 ± 10 %), chloride (2 ± 3 %), and elemental carbon (2 ± 2 %). Water-soluble organic matter (WSOM) extracted from two aerosol samples (9/24 and 9/25) collected consecutively during a pollution event were analyzed using ultrahigh-resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Approximately 4000 molecular formulas were assigned to each of the mass spectra in the range of m/z 100–1000. The majority of the assigned molecular formulas had unsaturated structures with CHO and CHNO elemental compositions. FLEXPART retroplume analyses showed the sampled air masses were very aged (average plume age > 12 days). These aged aerosol WSOM compounds had an average O /C ratio of ∼ 0.45, which is relatively low compared to O /C ratios of other aged aerosol. The increase in aerosol loading during the measurement period of 9/24 was linked to biomass burning emissions from North America by FLEXPART retroplume analysis and Moderate Resolution Imaging Spectroradiometer (MODIS) fire counts. This was confirmed with biomass burning markers detected in the WSOM and with the morphology and mixing state of particles as determined by scanning electron microscopy. The presence of markers characteristic of aqueous-phase reactions of phenolic species suggests that the aerosol collected at the Pico Mountain Observatory had undergone cloud processing before reaching the site. Finally, the air masses of 9/25 were more aged and influenced by marine emissions, as indicated by the presence of organosulfates and other species characteristic of marine aerosol. The change in the air masses for the two samples was corroborated by the changes in ethane, propane, and ozone, morphology of particles, as well as by the FLEXPART retroplume simulations. This paper presents the first detailed molecular characterization of free tropospheric aged aerosol intercepted at a lower free troposphere remote location and provides evidence of low oxygenation after long-range transport. We hypothesize this is a result of the selective removal of highly aged and polar species during long-range transport, because the aerosol underwent a combination of atmospheric processes during transport facilitating aqueous-phase removal (e.g., clouds processing) and fragmentation (e.g., photolysis) of components.
Found in: ključnih besedah
Summary of found: ...consecutively during a pollution event were analyzed using ultrahigh- resolution electrospray ionization Fourier transform ion cyclotron resonance mass...
Keywords: organic aerosol, ultrahigh-resolution FT-ICR MS, electron microscopy, remote marine atmosphere, Pico Mountain Observatory
Published: 11.04.2021; Views: 516; Downloads: 0
.pdf Fulltext (4,36 MB)

Gender agreement with exclusive disjunction in Slovenian
Franc Marušič, Zheng Shen, 2021, original scientific article

Abstract: This paper addresses two issues: 1. Empirically, we report novel experimental data on agreement with exclusively disjoined subjects in Slovenian; 2. Theoretically, we look into the nature of attested agreement strategies with coordinated NPs. In particular, we investigate how these strategies behave under coordinators with different semantics, i.e. exclusive disjunction and conjunction. Based on the elicitation results, we argue that closest conjunct agreement, resolved agreement, and highest conjunct agreement are all present under exclusive disjunction to different extents, which suggests a uniform set of agreement strategies under disjunction and conjunction despite the semantic difference. Further, we argue against the presence of default agreement under both disjunction and conjunction in Slovenian, and argue for a particular set of gender resolution rules.
Found in: ključnih besedah
Summary of found: ...argue for a particular set of gender resolution rules....
Keywords: Slovenian, conjunct agreement, exclisuve disjunction, resolution, default agreement
Published: 15.11.2021; Views: 186; Downloads: 0
.pdf Fulltext (997,87 KB)

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