1. Why are the Early Gothic murals in St. Jacob’s Church in Ormož, Slovenia, almost entirely black?Anabelle Križnar, Katja Kavkler, Sabina Dolenec, 2024, izvirni znanstveni članek Povzetek: In St. Jacob’s parish church in Ormož, Slovenia, mural paintings from around 1350–1370 are partially conserved in the northeastern corner of the main nave. They are almost completely black, indicating a large-scale pigment degradation. They were studied as a part of a larger research project aiming to identify materials applied and their possible degradation. First, they were studied in situ, and next, extracted samples of plaster, pigments, and colour layers were analysed by optical microscopy, Raman spectroscopy, FTIR spectroscopy, SEM-EDS, and XRD. Haematite, green earth, malachite, azurite, and tenorite were identified, showing that azurite and perhaps also malachite degraded to black tenorite, probably due to their fine grinding and their application directly on the fresh plaster. The plaster is made with small and large amounts of aggregate with mostly quartz with some impurities, which makes it fragile. The original appearance of these murals was of bright blue and green colours.
Ključne besede: mural painting, medieval painting, Gothic art, St. Jacob's Church, Ormož, Slovenia, pigments, chemical structure, colour degradation, optical microscopy, Raman microspectroscopy, FTIR, XRD
Objavljeno v DiRROS: 17.04.2024; Ogledov: 94; Prenosov: 49
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2. Weathering effects on cellulose acetate microplastics from discarded cigarette buttsBranka Mušič, Andrijana Sever Škapin, 2024, objavljeni znanstveni prispevek na konferenci (vabljeno predavanje) Povzetek: Cellulose acetate, commonly used in cigarette filters, poses environmental concerns due to its questionable (bio)degradability and prevalent presence in nature. This study compares the weathering effects on two types of cigarette filters: traditional and newer filters used in heated tobacco devices (HTP). Microplastics were derived from used cigarette parts and then subjected to artificial aging. Analytical techniques (Thermogravimetry-Differential Scanning Calorimetry TG/DSC, Fourier-Transform Infrared Spectroscopic Analysis (FTIR)) and loose bulk density measurements were employed pre- and post-aging cellulose acetate of both types of samples. Despite increasing evidence influencing European Union (EU) directives on tobacco product disposal, there's a lack of systematic analysis on the weathering impact, especially concerning the touted environmental benefits of newer filters. Results indicate decreased particle size in cellulose acetate filters post-aging. Variances were observed in thermal behavior, yet FTIR spectra remained unchanged.
Ključne besede: cellulose acetate, cigarette filters, microplastics, artificial weathering, polymer degradation
Objavljeno v DiRROS: 12.03.2024; Ogledov: 130; Prenosov: 140
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3. Degradation and Stabilization of Polymer MaterialsBranka Mušič, Andrijana Sever Škapin, 2023, kratki znanstveni prispevek Ključne besede: polymer-based materials, nano, micro, and macro composites, effects on (micro) organisms and toxicity, impact on the ecosystem, mechanisms and products of accelerated aging and degradation, physical, chemical, mechanical, thermal, and morphological, analysis, biodegradability, sustainability, life cycle, renewable and recycled resources and the circular economy
Objavljeno v DiRROS: 21.12.2023; Ogledov: 257; Prenosov: 92
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4. UV light causes structural changes in microplastics exposed in bio-solidsS. S. Alavian Petroody, Seyed Hossein Hashemi, Luka Škrlep, Branka Mušič, Cornelis A. M. van Gestel, Andrijana Sever Škapin, 2023, izvirni znanstveni članek Povzetek: Bio-solids (biological sludge) from wastewater treatment plants are a significant source of the emission of microplastics (MPs) into the environment. Weakening the structure of MPs before they enter the environment may accelerate their degradation and reduce the environmental exposure time. Therefore, we studied the effect of UV-A and UV-C, applied at 70 °C, on three types of MPs, polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET), that are commonly found in sewage sludge, using three shapes (fibers, lines, granules). The MPs were exposed to UV radiation in bio-solid suspensions, and to air and water as control. The structural changes in and degradation of the MPs were investigated using Attenuated Total Reflectance–Fourier Transform Infrared Spectrometry (ATR-FTIR) and surface morphology was performed with SEM analysis. UV exposure led to the emergence of carbonyl and hydroxyl groups in all of the PP samples. In PE and PET, these groups were formed only in the bio-solid suspensions. The presence of carbonyl and hydroxyl groups increased with an increasing exposure time. Overall, UV radiation had the greatest impact on the MPs in the bio-solids suspension. Due to the surface-to-volume ratio of the tested samples, which influences the degradation rate, the fibers were more degraded than the other two plastic shapes. UV-A was slightly more effective at degrading the MPs than UV-C. These findings show that ultraviolet radiation in combination with an elevated temperature affects the structure of polymers in wastewater bio-solids, which can accelerate their degradation.
Ključne besede: microplastics, degradation, hydroxyl, carbonyl, ultraviolet light
Objavljeno v DiRROS: 14.11.2023; Ogledov: 311; Prenosov: 161
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5. The LANDSUPPORT geospatial decision support system (S-DSS) vision : operational tools to implement sustainability policies in land planning and managementFabio Terribile, Marco Acutis, Antonella Agrillo, Erlisiana Anzalone, Sayed Azam-Ali, Marialaura Bancheri, Peter Baumann, Barbara Birli, Antonello Bonfante, Marco Botta, Mitja Ferlan, Jernej Jevšenak, Primož Simončič, Mitja Skudnik, 2023, izvirni znanstveni članek Povzetek: Nowadays, there is contrasting evidence between the ongoing continuing and widespread environmental degradation and the many means to implement environmental sustainability actions starting from good policies (e.g. EU New Green Deal, CAP), powerful technologies (e.g. new satellites, drones, IoT sensors), large databases and large stakeholder engagement (e.g. EIP-AGRI, living labs). Here, we argue that to tackle the above contrasting issues dealing with land degradation, it is very much required to develop and use friendly and freely available web-based operational tools to support both the implementation of environmental and agriculture policies and enable to take positive environmental sustainability actions by all stakeholders. Our solution is the S-DSS LANDSUPPORT platform, consisting of a free web-based smart Geospatial CyberInfrastructure containing 15 macro-tools (and more than 100 elementary tools), co-designed with different types of stakeholders and their different needs, dealing with sustainability in agriculture, forestry and spatial planning. LANDSUPPORT condenses many features into one system, the main ones of which were (i) Web-GIS facilities, connection with (ii) satellite data, (iii) Earth Critical Zone data and (iv) climate datasets including climate change and weather forecast data, (v) data cube technology enabling us to read/write when dealing with very large datasets (e.g. daily climatic data obtained in real time for any region in Europe), (vi) a large set of static and dynamic modelling engines (e.g. crop growth, water balance, rural integrity, etc.) allowing uncertainty analysis and what if modelling and (vii) HPC (both CPU and GPU) to run simulation modelling ‘on-the-fly’ in real time. Two case studies (a third case is reported in the Supplementary materials), with their results and stats, covering different regions and spatial extents and using three distinct operational tools all connected to lower land degradation processes (Crop growth, Machine Learning Forest Simulator and GeOC), are featured in this paper to highlight the platform's functioning. Landsupport is used by a large community of stakeholders and will remain operational, open and free long after the project ends. This position is rooted in the evidence showing that we need to leave these tools as open as possible and engage as much as possible with a large community of users to protect soils and land.
Ključne besede: land degradation, land management, soil, spatial decision support system, sustainability
Objavljeno v DiRROS: 13.11.2023; Ogledov: 374; Prenosov: 170
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6. Influence of weathering on the degradation of cellulose acetate microplastics obtained from used cigarette buttsBranka Mušič, Anita Jemec Kokalj, Andrijana Sever Škapin, 2023, izvirni znanstveni članek Povzetek: Cellulose acetate is used in many applications, including for cigarette filters. Unfortunately, unlike cellulose, its (bio)degradability is under question, yet it often ends up uncontrolled in the natural environment. The main purpose of this study is to compare the effects of weathering on two types of cigarette filter (classic filters and newer filters that have more recently arrived on the market) following their use and disposal in nature. Microplastics were prepared from polymer parts of used (classic and heated tobacco products—HTP) cigarettes and artificially aged. TG/DTA, FTIR, and SEM analyses were performed both before and after the aging process. Newer tobacco products contain an additional film made of a poly(lactic acid) polymer which, like cellulose acetate, burdens the environment and poses a risk to the ecosystem. Numerous studies have been conducted on the disposal and recycling of cigarette butts and cigarette butt extracts, revealing alarming data that have also influenced the decisions of the EU, who addressed the disposal of tobacco products in the EU Directive (EU) 2019/904. Despite this, there is still no systematic analysis in the literature evaluating the impact of weathering (i.e., accelerated aging) on the degradation of cellulose acetate in classic cigarettes compared with that in newer tobacco products that have recently appeared on the market. This is of particular interest given that the latter have been promoted as being healthier and environmentally friendly. The results show that in cellulose acetate cigarette filters the particle size decreased after accelerated aging. Also, the thermal analysis revealed differences in the behavior of the aged samples, while the FTIR spectra showed no shifts in the position of the peaks. Organic substances break down under UV light, which can be seen by measuring the color change. The PLA film was found to be more stable than cellulose acetate under the influence of UV light.
Ključne besede: cellulose acetate, cigarette filters, microplastics, artificial weathering, polymer degradation
Objavljeno v DiRROS: 30.06.2023; Ogledov: 353; Prenosov: 220
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7. Mechanistic study of fast performance decay of PtCu alloy-based catalyst layers for polymer electrolyte fuel cells through electrochemical impedance spectroscopyMaximilian Grandi, Matija Gatalo, Ana Rebeka Kamšek, Gregor Kapun, Kurt Mayer, Francisco Ruiz-Zepeda, Martin Šala, Bernhard Marius, Marjan Bele, Nejc Hodnik, Merit Bodner, Miran Gaberšček, Viktor Hacker, 2023, izvirni znanstveni članek Ključne besede: PEFC, catalyst layer, platinum–copper, degradation, ionomer, electrochemical impedance spectroscopy, membrane electrode assembly
Objavljeno v DiRROS: 23.06.2023; Ogledov: 355; Prenosov: 183
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9. Magnetic extraction of weathered tire wear particles and polyethylene microplasticsVaibhav Budhiraja, Branka Mušič, Andrej Kržan, 2022, izvirni znanstveni članek Povzetek: Magnetic extraction offers a rapid and low-cost solution to microplastic (MP) separation, in which we magnetize the hydrophobic surface of MPs to separate them from complex environmental matrices using magnets. We synthesized a hydrophobic Fe-silane based nanocomposite (Fe@SiO2/MDOS) to separate MPs from freshwater. Pristine and weathered, polyethylene (PE) and tire wear particles (TWP) of different sizes were used in the study. The weathering of MPs was performed in an accelerated weathering chamber according to ISO 4892-2:2013 standards that mimic natural weathering conditions. The chemical properties and morphology of the Fe@SiO2/MDOS, PE and TWP were confirmed by Fourier transform infrared spectroscopy and Scanning electron microscopy, respectively. The thermal properties of PE and TWP were evaluated by Thermogravimetric analysis. Using 1.00 mg of Fe@SiO2/MDOS nanocomposite, 2.00 mg of pristine and weathered PE were extracted from freshwater; whereas, using the same amount of the nanocomposite, 7.92 mg of pristine TWP and 6.87 mg of weathered TWP were extracted. The retrieval of weathered TWP was 13% less than that of pristine TWP, which can be attributed to the increasing hydrophilicity of weathered TWP. The results reveal that the effectiveness of the magnetic separation technique varies among different polymer types and their sizes; the weathering of MPs also influences the magnetic separation efficiency.
Ključne besede: degradation, magnetic separation, microplastics, polyethylene, tire wear particles, open access
Objavljeno v DiRROS: 03.05.2023; Ogledov: 413; Prenosov: 356
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10. Photocatalytic, electrocatalytic and photoelectrocatalytic degradation of pharmaceuticals in aqueous media : analytical methods, mechanisms, simulations, catalysts and reactorsBelisa Alcantara Marinho, Luka Suhadolnik, Blaž Likozar, Matej Huš, Živa Marinko, Miran Čeh, 2022, pregledni znanstveni članek Ključne besede: advanced oxidation process, persistent organic compounds, pharmaceutical by- products, degradation mechanism, reactor design, analytical methods
Objavljeno v DiRROS: 10.03.2022; Ogledov: 639; Prenosov: 516
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