41. Degradation of microplastics in the environment : dissertationVaibhav Budhiraja, 2024, doktorska disertacija Opis: Plastics are based on organic polymers that are sensitive to the environment in which they find themselves and will gradually decay through a variety of chemical reactions. This process is of great importance for the transformation and persistence of microplastics (MPs) that pollute the environment. The rate of degradation depends on two major factors: Firstly, the intrinsic properties of the polymers, such as chemical structure, molecular weight, crystallinity and the presence of additives, fillers or reinforcement and secondly, the environment to which they are exposed. The degradation rate of plastic will vary in different environmental matrices like soil, freshwater, seawater, wastewater, land etc., as well as in diverse environmental conditions like UV radiation, temperature, humidity, the effect of pollutants etc. Plastic mainly undergoes two fundamental reactions: oxidation and hydrolysis and the chemical structure of the polymer and its additives plays a key role in the degradation mechanism of plastic. Polyolefins having a carbon-only main chain are resistant to hydrolysis but susceptible to oxidation, whereas polyesters and polyamides containing heteroatoms are sensitive to hydrolysis and much more resistant to oxidation.
In the context of the present work, five different studies were done involving both naturally degraded plastic and accelerated weathering of plastics in the form of small particles, MPs. In the first study, natural degraded polyethylene (PE) and polypropylene (PP) samples with a life span of more than forty years were collected from the environment and their physiochemical properties were analysed. The results show that red coloured PE samples were more degraded as compared to blue coloured samples, indicating that pigment plays a key role in the degradation. The PP sample shows extreme surface degradation, leading to fragmentation and the generation of MPs. In the second study, the effect of hydrodynamic cavitation on MPs in waste water treatment plant sludge was evaluated. PE, PP, polyethylene terephthalate and polyamide were extracted from the sludge. It was found that hydrodynamic cavitation does not disintegrate the MPs, although it removes some toxic metals and shows cell disruption mechanisms.
Other studies were done with accelerated weathered MPs, which include PE, PP and tire wear particles (TWP), that were treated in accordance with an ISO 4892 standard weathering procedure that mimics natural weathered conditions. In the third study, we used weathered PE films to evaluate the synergistic adsorption behaviour of two pollutants, namely triclosan (TCS) and methylparaben (MeP). It was found that weathered MPs adsorb more pollutants and the adsorption behaviour of TCS is enhanced in the presence of MeP. In the fourth study, the magnetic extraction of pristine and weathered PE and TWP particles was performed. The results confirmed that the magnetic
VI
extraction of weathered MPs is difficult as compared to pristine MPs as their surface becomes more hydrophilic with weathering. In the fifth study, the effect of weathering on the density of PE and PP was evaluated. We found that weathering enhances the density of polyolefins, which is one of the main reasons for the observed sinking of polyolefin MPs in water. Ključne besede: accelerated weathering, aging, density, magnetic separation, pigment, plastic degradation, pollutants, polyethylene, polyolefin, polypropylene, sinking, tire wear particles, dissertations Objavljeno v RUNG: 04.06.2024; Ogledov: 391; Prenosov: 0 Celotno besedilo (7,35 MB) |
42. Annual variation of source contributions to ▫$PM_10$▫ and oxidative potential in a mountainous area with traffic, biomass burning, cement-plant and biogenic influencesKristina Glojek, Thuy Vy Dinh Ngoc, Sylvain Weber, Gaëlle Uzu, M. Manousakas, R. Elazzouzi, Katja Džepina, S. Darfeuil, Patrick Ginot, Andrej Podkoritnik, Griša Močnik, 2024, izvirni znanstveni članek Ključne besede: air pollution, extensive PM chemical characterization, positive matrix factorization (PMF), new source identification, health metric Objavljeno v RUNG: 03.06.2024; Ogledov: 417; Prenosov: 1 Celotno besedilo (3,58 MB) Gradivo ima več datotek! Več... |
43. Placement and ordering of the (en)cliticsFranc Marušič, Petra Mišmaš, Rok Žaucer, 2024, samostojni znanstveni sestavek ali poglavje v monografski publikaciji Ključne besede: clitics, enclitics, Slavic, syntax, Slovenian, Slovak, Czech, Bulgarian, Macedonian, BCMS, Polish, clitic cluster, stress Objavljeno v RUNG: 31.05.2024; Ogledov: 341; Prenosov: 1 Povezava na datoteko Gradivo ima več datotek! Več... |
44. Lensed type Ia supernova “Encore” at z=2 : the first instance of two multiply imaged supernovae in the same host galaxyJustin Pierel, A. B. Newman, S. Dhawan, M. Gu, B. A. Joshi, T. Li, S. Schuldt, L. G. Strolger, S. H. Suyu, Tanja Petrushevska, 2024, izvirni znanstveni članek Ključne besede: supernova, James Webb Space Telescope, Hubble constant Objavljeno v RUNG: 31.05.2024; Ogledov: 462; Prenosov: 3 Celotno besedilo (953,07 KB) Gradivo ima več datotek! Več... |
45. Instruct-ERIC network : biophysical characterization of antigen-nanobody complexesClaudia D'Ercole, 2024, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Forest environments are exposed to multiple stressful factors of both abiotic and biotic nature which may lead to their massive decline [1]. Understanding the molecular mechanisms of specific stress conditions and monitoring the fluctuations of reliable forest plant biomarkers with affordable methods would be instrumental for assessing stress levels over the time. Ascorbate peroxidase (APX) represents a suitable plant biomarker. APX is a hydrogen peroxide-scavenging enzyme the critical role of which has been described in several plants, both herbaceous and woody. Its activity generally increases under oxidative stress during which its peroxide detoxifying function is part of the wider ascorbate-glutathione cycle [2]. The development of reagents to detect such fluctuations would help the evaluation of plant physiological conditions. In this study, nanobodies (Nbs) targeting APX have been identified. Nbs correspond to the variable domain of heavy chain-only antibodies derived from camelids. They are small (15 kDa), stable, and can be easily produced in bacteria fused to different protein tags according to the downstream applications [3]. After their isolation by biopanning against soluble APX, they have been produced and underwent a biophysical characterization in combination with their antigen (APX-Nb complex) to identify the best binders in terms of stability and affinity. The protein complex characterization was supported by Instruct-ERIC and mainly performed at the BIOCEV institute of Prague. Data from Mass Photometry and Dynamic Light scattering evidenced the formation of the protein complexes, whereas the preliminary data of Hydrogen-Deuterium Exchange Mass Spectrometry, performed with the aim of identifying the residues involved in the paratope/epitope interface, were insufficient to clarify the issue and rather suggested that the interaction has low affinity. This indication was then confirmed by ELISA assay. The combination of multiple methods allowed a comprehensive sample characterization which will require further structural analyses to provide a complete picture of the APX-Nb complex.
[1] G. Marie. B. C. M. B. C. Walters, “Forest decline and tree mortality in a southeastern Ohio oak-hickory forest,” Ohio Journal of Science , vol. 97, 1997.
[2] O. Chew, J. Whelan, and A. H. Millar, “Molecular Definition of the Ascorbate-Glutathione Cycle in Arabidopsis Mitochondria Reveals Dual Targeting of Antioxidant Defenses in Plants,” Journal of Biological Chemistry, vol. 278, no. 47, 2003, doi: 10.1074/jbc.M307525200.
[3] S. Muyldermans, “A guide to: generation and design of nanobodies,” FEBS J, vol. 288, no. 7, pp. 2084–2102, Apr. 2021, doi: 10.1111/febs.15515. Ključne besede: nanobody, ascorbate peroxidase, plant stress, protein complex, biophysical methodologies Objavljeno v RUNG: 31.05.2024; Ogledov: 451; Prenosov: 0 Gradivo ima več datotek! Več... |
46. Multi-layer palladium diselenide as a contact material for two-dimensional tungsten diselenide field-effect transistorsGennadiy Murastov, Muhammad Awais Aslam, Simon Leitner, Vadym Tkachuk, Iva Plutnarová, Egon Pavlica, Raul D. Rodriguez, Zdeněk Sofer, Aleksandar Matković, 2024, izvirni znanstveni članek Opis: Tungsten diselenide (WSe2) has emerged as a promising ambipolar semiconductor material for field-effect transistors (FETs) due to its unique electronic properties, including a sizeable band gap, high carrier mobility, and remarkable on–off ratio. However, engineering the contacts to WSe2 remains an issue, and high contact barriers prevent the utilization of the full performance in electronic applications. Furthermore, it could be possible to tune the contacts to WSe2 for effective electron or hole injection and consequently pin the threshold voltage to either conduction or valence band. This would be the way to achieve complementary metal–oxide–semiconductor devices without doping of the channel material.This study investigates the behaviour of two-dimensional WSe2 field-effect transistors with multi-layer palladium diselenide (PdSe2) as a contact material. We demonstrate that PdSe2 contacts favour hole injection while preserving the ambipolar nature of the channel material. This consequently yields high-performance p-type WSe2 devices with PdSe2 van der Waals contacts. Further, we explore the tunability of the contact interface by selective laser alteration of the WSe2 under the contacts, enabling pinning of the threshold voltage to the valence band of WSe2, yielding pure p-type operation of the devices. Ključne besede: field-effect transistor, tungsten diselenide, van der Waals, two-dimensional materials Objavljeno v RUNG: 29.05.2024; Ogledov: 539; Prenosov: 3 Celotno besedilo (3,06 MB) Gradivo ima več datotek! Več... |
47. Sustainable digital preservation of new media artNarvika Bovcon, Eszter Polónyi, Jaka Železnikar, Aleš Vaupotič, 2023, objavljeni znanstveni prispevek na konferenci Opis: This paper is about two pilot studies conducted in 2022 that aimed to develop a model for preserving and archiving new media art work in the context of a research project on the sustainable digital preservation of new media art that is being co-hosted by the Museum of Modern Art in Ljubljana. As the works of art selected for the study by Slovenian new media art pioneers Vuk Ćosić (2000) and Srečo Dragan (2005) were technically obsolete or non-functional by the time of the study, the question of how to bring the artworks back into existence and what components of each artwork to include in the collection and preservation process constituted one aspect of our research. But this process of reconstruction also raised questions about how the preservation of media art is reshaping the practice of archiving within an institution whose holdings were, until recently, largely in traditional mediums. An interdisciplinary approach addressed the problem from different points of view, involving the practitioners, experts from art-history, museology, computer science, media theory and intellectual property rights. Ključne besede: digital cultural heritage, new media art preservation, new media art archives Objavljeno v RUNG: 28.05.2024; Ogledov: 432; Prenosov: 2 Celotno besedilo (5,46 MB) Gradivo ima več datotek! Več... |
48. |
49. |
50. Oxidative potential of particulate matter and its association to respiratory health endpoints in high-altitude cities in BoliviaLucille Borlaza-Lacoste, Valeria Mardoñez, Anouk Marsal, Ian Hough, Thuy Vy Dinh Ngoc, Pamela Dominutti, Jean-Luc Jaffrezo, Andrés Alastuey, Jean-Luc Besombes, Griša Močnik, 2024, izvirni znanstveni članek Ključne besede: particulate matter, oxidative potential, respiratory health, Bolivia, source apportionment, Positive matrix factorization, Poisson regression Objavljeno v RUNG: 22.05.2024; Ogledov: 466; Prenosov: 0 Povezava na datoteko Gradivo ima več datotek! Več... |