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11.
Polygroup objects in regular categories
Alessandro Linzi, 2024, izvirni znanstveni članek

Opis:

We express the fundamental properties of commutative polygroups (also known as canonical hypergroups) in category-theoretic terms, over the category $ \mathbf{Set} $ formed by sets and functions. For this, we employ regularity as well as the monoidal structure induced on the category $ {\mathbf{Rel}} $ of sets and relations by cartesian products. We highlight how our approach can be generalised to any regular category. In addition, we consider the theory of partial multirings and find fully faithful functors between certain slice or coslice categories of the category of partial multirings and other categories formed by well-known mathematical structures and their morphisms.


Ključne besede: polygroup, canonical hypergroup, multiring, Krasner hyperring, regular category, relation
Objavljeno v RUNG: 25.03.2024; Ogledov: 81; Prenosov: 2
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Organic and flexible : lecture at Ženske v znanosti in za znanost, Ljubljana, 12. 2. 2024
Nadiia Pastukhova, 2024, prispevek na konferenci brez natisa

Opis: The development of organic semiconductors (OS) opens a new perspective and possibilities for novel device architectures including flexible and wearable electronics. One of the key parameters is the charge carriers' mobility. In OSs, it is affected by many factors, including molecular stacking, chemical impurities, temperature, pressure, electric field, and charge carrier density. These factors can affect the structural or energetic disorder. To overcome limitations, new polymers that extend the π-conjugation to two dimensions were developed. The two-dimensional network structure provides a high degree of structural stability and tunability of properties, while the organic molecules can be engineered to exhibit specific chemical and physical properties such as large surface area, pore size, and electronic properties. I will present our recent research, where quasi-2D polyacetylene (q2DPA) demonstrates high electron mobility along the direction of the layer, measured by the lateral time-of-flight photoconductivity (TOF) method.
Ključne besede: 2D polymers, time-of-flight photoconductivity, TOF, organic semiconductors
Objavljeno v RUNG: 22.03.2024; Ogledov: 138; Prenosov: 2
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Comparing black-carbon- and aerosol-absorption-measuring instruments : a new system using lab-generated soot coated with controlled amounts of secondary organic matter
Daniel M. Kalbermatter, Griša Močnik, Luka Drinovec, Bradley Visser, Jannis Röhrbein, Matthias Oscity, Ernest Weingartner, Antti-Pekka Hyvärinen, Konstantina Vasilatou, 2022, zaključena znanstvena zbirka raziskovalnih podatkov

Opis: A preprint of the publication can be found here: AMTD - Response of black carbon and aerosol absorption measuring instruments to laboratory-generated soot coated with controlled amounts of secondary organic matter (copernicus.org) (doi.org/10.5194/amt-2021-214). The files correspond to the raw data sets used for Figures 3 and 4 of the aforementioned publication. The date and start/stop time of the measurements are listed in the file "overview_measurements".
Ključne besede: aerosol absorption coefficient, black carbon, absorption enhancement
Objavljeno v RUNG: 19.03.2024; Ogledov: 158; Prenosov: 2
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17.
Engineering of functional nanosnowflakes from gold nanocarriers capped with amino-modified DNA oligonucleotides
Alexandre Loukanov, Velichka Arahangelova, Saim Emin, Chavdar Filipov, 2023, izvirni znanstveni članek

Opis: Abstract The design, engineering and electron microscopic characterization of anisotropic nanosized snowflake‐like structural assemblies (nanosnowflakes) is reported. They were fabricated through immobilization of double stranded amine‐modified and thiol‐terminated DNA oligonucleotides on the surface of ultra‐small isotropic gold nanoparticles used as nanocarriers. The transmission electron microscopy images combined with spectrophotometric data revealed the formation of self‐assembled structural aggregation between individual ligands‐coated nanoparticles. They act as seeds for the further spontaneous dendritic growth in different directions. Their anisotropic morphology is formed due to the occurrence of facilitated electrostatic interactions between positive charged amino‐groups and the negative sugar‐phosphate backbone of oligonucleotides. Thus, nanosnowflakes with size distribution between 40 and 80 nm were obtained. The microscopic analysis demonstrated also that the stable nanosnowflakes structure was highly dependent on the solution ionic strength, which effect the charge fluctuation within the assembly. The reported DNA functionalized nanostructures have potential to be applied as a platform for development of therapeutic materials, as well as drug delivery nanosystems. Research Highlights The engineering, fabrication, and microscopic characterization of DNA nanosnowflakes is reported. The electron microscopy analysis revealed formation of self‐assemblies with anisotropic morphology. The nanosnowflakes size distribution was between 40 and 80 nm.
Ključne besede: DNA, nanocarrier, functionalization, drug delivery
Objavljeno v RUNG: 18.03.2024; Ogledov: 155; Prenosov: 0
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18.
The Virtual Alpine Observatory (VAO) acting to better observe, understand, forecast and react to climate change in a combined Network of European High-Altitude Research Stations
Michael Krautblatter, Griša Močnik, 2024, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: The Alpine region undergoes a faster and more pronounced climate change than surrounding lowlands and, therefore, is a time machine showing the things to come in a changing climate and environment. Under the influence of a robust warming trend, witnessing an ascent of >1°C since the 1980s significant effects are visible and measurable in atmosphere, biosphere, hydrosphere, and most apparently the cryosphere. The Virtual Alpine Observatory is an assemblage comprising European Alpine Observatories, high alpine research facilities, data archives, and supercomputing centers, seamlessly interwoven through shared infrastructure and collaborative research pursuits. It is the answer to how the complex Alpine environmental system can be addressed by an interdisciplinary, cross-border collaborating research paradigm. At its core, the primary objective is to orchestrate collective endeavors aimed at observing, comprehending, and prognosticating the ramifications of climate change on the Alpine expanse. This extends to the multifaceted facets of the environment in multiple aspects. This alliance of researchers and data-gathering institutions spanning the Alpine landscape and analogous mountainous terrains in Europe propels the exploration of data patterns transcending national boundaries. In doing so, it creates a reservoir of data, knowledge and scientific approaches that surpasses the cumulative understanding derived from its individual constituents. In the upcoming discourse, we illuminate the network's future goals, composition, unveil forthcoming research initiatives, expound upon data availabilities, and deliberate on the trajectories that lie ahead for collaborative efforts. The VAO network is substantially funded by the Bavarian State Ministry of the Environment and Consumer Protection.
Ključne besede: Alpine observatory, climate change, Virtual Alpine Observatory
Objavljeno v RUNG: 18.03.2024; Ogledov: 145; Prenosov: 2
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19.
Particulate air pollution in the heart of the European Union : lessons learned from SAFICA 2017-2018 and SAAERO 2022-2023 projects in Central and Southeast Europe
Katja Džepina, Kristina Glojek, Martin Rigler, Asta Gregorič, Matic Ivančič, Irena Ježek, Griša Močnik, 2024, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: Particularly during the cold weather season, countries of the Southeast Europe are experiencing some of the poorest air quality in the world due to the extensive use of solid fuels and old vehicle fleets. The city of Sarajevo is the capital of Bosnia and Herzegovina (BiH) situated within a basin surrounded by mountains. In the winter months (domestic heating season), topography and meteorology cause the pollutants to be trapped within the city basin. Countries of the Southeast Europe lack state-of-the-art atmospheric sciences research and access to sophisticated instrumentation and methodology, despite high levels of ambient pollution and position within the European Union (EU) borders, making it imperative to understand the emission sources, processing and the adverse health effects of atmospheric aerosol pollution.                This presentation will highlight the field measurements in Central and Southeast Europe during the Sarajevo Canton Winter Field Campaign 2017-2018 (SAFICA) and Sarajevo Aerosol Experiment 2022-2023 (SAAERO) projects, centered at the Sarajevo Bjelave supersite. Both projects were envisioned to produce crucial, not previously available information about aerosol emission sources and atmospheric transformations through a combination of online field and offline laboratory measurements. Online measurements during a) SAFICA and b) SAAERO included, a) black carbon, particle number and size distribution, and b) carbonaceous species, elemental composition and bulk chemical composition. SAAERO online measurements also included stationary and mobile measurements of gas- and particle-phase species on board the mobile laboratory in Sarajevo and Zenica, BiH, as well as in Ljubljana, Slovenia and Zagreb, Croatia. Finally, extended SAAERO project included measurements of black carbon at three additional urban centers: Ljubljana, Zagreb, and Belgrade, Serbia, enabling the first comparison of urban air quality in Central and Southeast Europe between two EU and two non-EU capitals. During both projects, laboratory aerosol analyses determined aerosol bulk chemical composition, selected elements (Huremović et al., 2020; Žero et al., 2022) and molecular species (Pehnec et al., 2020). Aerosol chemical composition determined by aerosol mass spectrometry was further analyzed by Positive Matrix Factorization to separate organic aerosol into subtypes characteristic of specific sources and atmospheric processes. Aerosol oxidative potential was also determined to evaluate aerosol ability to generate reactive oxygen species. Sarajevo and Belgrade have high ambient loadings of aerosol and black carbon, indicative of strong and diverse combustion sources and a major public health hazard. Finally, aerosol surface concentrations will be discussed in the context of European air quality. We thank Jasminka Džepina, Magee Scientific/Aerosol, TSI and Aerodyne for support. We acknowledge the contribution of the COST Action CA16109 COLOSSAL and SEE Change Net. KDž and ASHP acknowledge the grant by the Swiss NSF (Scientific Exchanges IZSEZ0_189495), KDž, GM and ASHP European Commission SAAERO grant (EU H2020 MSCA-IF 2020 #101028909), GM Slovenian ARIS grant (P1-0385), SF Croatian HRZZ grant (BiREADI IP-2018-01-3105), and AG, MR, MI, BA and IBJ Slovenian ARIS grant (L1-4386). Pehnec, G., et al., Sci. Tot. Environ., 734, 139414, 2020. Huremović, J., et al., Air Qual. Atmos. Health, 13, 965–976, 2020. Žero, S., Žužul, S., et al., Environ. Sci. Technol., 56, 7052−7062, 2022.
Ključne besede: air pollution, sources of pollution, PMF
Objavljeno v RUNG: 18.03.2024; Ogledov: 161; Prenosov: 2
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20.
Phenomenology of organic aerosols light absorption in Europe based on in situ surface observations
Jordi Rovira, Jesús Yus-Díez, Griša Močnik, 2024, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: Both chamber and field experiments have shown that a fraction of organic aerosols (OA), called brown carbon (BrC), can efficiently absorb UV-VIS radiation with important effects on radiation balance. However, the optical properties of BrC, and its climate effects, remain poorly understood because a variety of chemical compositions are involved and their fractions vary with source and formation process. We present a phenomenology of OA light absorption in Europe using Aethalometer (AE) data. AE data were used to calculate the black carbon (BC) and BrC contribution to the total measured absorption in the UV-VIS spectral range (babs,BC(l), babsBrC(l)). Fig. 1 shows the BrC absorption at 370 nm and shows that the BrC absorption was on average higher in urban than in rural sites. Figure 1. Map of BrC absorption in rural and urban sites. At 18 out of 41 sites, simultaneous ACSM (Aerosol Chemical Speciation Monitor) data were available allowing reporting the mass absorption cross-section (MAC), the imaginary refractive index (k), the k Angström Exponent (w) of OA particles and OA sources. We compared the experimental data the with Saleh’s classification, that groups BrC in four optical classes, namely very weakly (VW-BrC), weakly (W-BrC), moderately (M-BrC) and strongly (S-BrC) absorbing BrC. Preliminary results show that both MAC and k of POA sources were higher compared to SOA sources and that BBOA (biomass burning OA) followed by CCOA (coal combustion OA) and HOA (hydrocarbon-like OA) dominated the absorption by BrC.  Data reported indicate a relationship between w and k with higher w associated to less absorbing OA particles. With this work we provide a robust experimental framework that can be used to better constrain the climate effect of OA particles represented in climate models. In our results we found that most of the measured ambient OA particles present from W to M absorption properties. Variations in OA k and w depend on the relative contribution of POA compared to SOA as also reflected by the higher k observed in winter compared to summer. Our results also demonstrate a strong variation of OA optical properties in Europe thus further confirming the complexity of OA absorption properties. This work was supported by the FOCI Project (G.A. 101056783) and ARRS P1-0385. Action Cost COLOSSAL. We thank the COLOSSAL Team for providing OA sources and AE33 data. Chen et al (2022). Env. Int. 166, 107325. Nakao et al (2013). Atm. Env. 68, 273-277. Canagaratna et al (2015). Atmos. Chem. Phys. 15, 253-272. Saleh et al (2020). Curr. Pollution Rep. 6, 90–104.
Ključne besede: black carbon, brown carbon, aerosol absorption coefficient
Objavljeno v RUNG: 18.03.2024; Ogledov: 167; Prenosov: 2
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