21. 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: 138
 Celotno besedilo (84,58 MB)
Gradivo ima več datotek! Več... |
22. Green transition in slovenian building and civil engineering industry : 10 years of research on alkali-activated materials and alkali-activated foamsBarbara Horvat, Branka Mušič, 2024, objavljeni znanstveni prispevek na konferenci (vabljeno predavanje) Povzetek: The building and civil engineering industry yearly causes more than 40% of man-made CO2 and consumes raw materials for two-thirds of Mont Everest. To decrease the carbon footprint and consumption of raw materials, alkali-activated materials (AAMs) are researched as an alternative to conventional building and civil engineering products like cements, mortar, and ceramics. Ideally, locally available waste materials are used as ingredients: (i) as precursors that react with alkali and form an aluminosilicate network, and (ii) as fillers that get permanently encapsulated and safely stored in AAMs. The addition of gas bubbles and lightweight fillers transforms AAMs into alkali-activated foams and alkali-activated lightweight materials that have the potential to be used as thermal and acoustic insulation materials. Although AAMs are researched worldwide, this review focuses on the state-of-the-art localised solely to Slovenia, particularly on the materials and curing procedures used, as well as on the scientific contribution of the basic research. Besides, the year 2024 marks 10 years of research on alkali activation of raw and waste inorganic materials in Slovenia.
Ključne besede: secondary raw material, alkali-activated material, alkali-activated foams, alkali, circular economy, microwave irradiation, mechanical strength
Objavljeno v DiRROS: 12.03.2024; Ogledov: 107; Prenosov: 102
Celotno besedilo (84,58 MB)
Gradivo ima več datotek! Več... |
23. Influence of ammonium polyphosphates and 2,4,6-triamino-1,3,5-triazine on the mechanical-physical properties of polyurethane and alkali-activated materialsBranka Mušič, Barbara Horvat, 2024, objavljeni znanstveni prispevek na konferenci Povzetek: In building constructions, the tendency towards an ever-better material directs us to composite materials. In this work, we prepared an organic-organic and organic-inorganic composite material by incorporating fire retardants, ammonium polyphosphates, and 2,4,6-triamino-1,3,5-triazine, into a polyurethane network and an aluminosilicate network (ASN) of alkali-activated material. Polyurethane foams (PUR) are well-known materials that, due to their properties, such as low weight-to-strength ratio, low electrical and thermal conductivity, flexibility, and relatively simple preparation process, are used in various industries, also in the construction industry, e.g., for thermal insulation of windows and doors or fixing and sealing joinery. Opposite, the ASN of alkali-activated metakaolin, successfully paves the way for new applications, such as high-temperature protection. In this paper, these interactive properties of prepared composites are studied using thermal testing and mechanical analysis. It was found that inhibitors significantly increase the fire resistance of PUR systems while they slightly reduce the mechanical properties. Incorporating polymer flame retardant into ASN in building products, such as façade panels , can decrease the mechanical properties but can offer the non-flammable building envelope not get heated from burning surroundings, i.e., not becoming a convection heat source, but rather represent a fire-distinguisher for flammable materials.
Ključne besede: flame retardants, polyurethane, alkali activated material, metakaolin, microwave irradiation, mechanical strength
Objavljeno v DiRROS: 12.03.2024; Ogledov: 93; Prenosov: 45
Celotno besedilo (2,52 MB)
Gradivo ima več datotek! Več... |
24. Waste rubber incorporated in the alkali-activated metakaolin’s aluminosilicate network enhanced by microwave irradiationBarbara Horvat, Branka Mušič, 2024, objavljeni znanstveni prispevek na konferenci Povzetek: Building materials represent the possibility of prolonging the life of waste materials. The key is to ensure that the products are suitable for their function. So we activated metakaolin with the alkaline Na-silicate solution in the ratio that ensures the prevention of efflorescence and high mechanical strength (Horvat and Ducman, 2019). As the waste material (to be incorporated in the aluminosilicate network (ASN) of the alkali-activated metakaolin) ground waste rubber from electric cables was used in the preselected mass ratios. Its inclusion in products, like paving stones, can reduce stiffness, improve durability, dampen vibrations, and reduce road noise. The mechanical strengths of test samples with rubber present on the active surface or slightly below were higher compared to samples where rubber was encapsulated throughout the volume. Compressive strength was higher when samples were irradiated with low powers of microwaves while irradiation with higher powers led to the foaming of alkali-activated slurry. The encapsulation quality of the ground rubber was evaluated by SEM while the chemical influence on ASN was determined by EDS, FTIR, and XRD. Slipperiness change on the active surface of pavement stones proved that the addition of the ground rubber enhanced the walking safety of the product.
Ključne besede: secondary raw material, alkali activated material, waste rubber, metakaolin, encapsulation of organic in inorganic material, microwave irradiation, mechanical strength
Objavljeno v DiRROS: 12.03.2024; Ogledov: 100; Prenosov: 47
Celotno besedilo (13,99 MB)
Gradivo ima več datotek! Več... |
25. |
26. |
27. |
28. Analysis of alkali-activated mineral wool-slag binders : evaluating the differences between one-part and two-part variationsElijah Adesanya, Rawia Dabbebi, Christine Rößler, Majda Pavlin, Zhenming Li, Tero Luukkonen, Juho Yliniemi, Mirja Illikainen, 2024, izvirni znanstveni članek Povzetek: Two synthesis pathways (one- and two-part) in alkali-activated binders were compared using ground granulated blast furnace slag (GGBFS), mineral wool (MW) activated using dry and liquid alkali activators with similar Na2O/SiO2 modulus. The effect of activator type on reaction kinetics, strength development, setting times, and durability shows that one-part synthesis does not only improve early strength, but also provide better durability properties. While the highest compressive strength (56 MPa, 90 days) was achieved for the one-part mix (DM), the reaction products (presence of Mg–Al layered double hydroxide and C–S–H-like phases) observed for both mortar mixes were similar. The DM mortars showed better resistance to sulfate attack than two-part mix (WM) mortars and sets faster. The results highlight the significance of the one-part pathways in the synthesis of alkali-activated materials.
Ključne besede: recycling, alkali activated material, mineral wool
Objavljeno v DiRROS: 11.03.2024; Ogledov: 105; Prenosov: 76
Celotno besedilo (1,28 MB)
Gradivo ima več datotek! Več... |
29. Ornate Bairdiidae (Ostracoda) in 3 dimensions : exploring carapace morphology and pore canals of Triebelina van den Bold, 1946, Nodobairdia Kollmann, 1963 and Mirabairdia Kollmann, 1963Marie-Béatrice Forel, Nathalie Poulet-Crovisier, Lidija Korat, Rosalie F. Maddocks, 2024, izvirni znanstveni članek Povzetek: Marine ostracods of the family Bairdiidae Sars, 1888 have an evolutionary history starting from the Ordovician with an explosive diversification of ornate forms during the Triassic. Representatives of the family are notoriously homeomorphic, which makes their taxonomy a major challenge of modern ostracodology. Their classification has thus been problematic since the 1970s. Here we present the first CT-scan investigation of recent and fossil ornate Bairdiidae valves in order to characterize and evaluate the taxonomic significance of unexploited characters, such as pores and pore canals. Thanks to 3D tomography, we explore the distribution of pores at the surface and the pathway of pore ca- nals within the valve wall of the recent genus Triebelina van den Bold, 1946 and the Triassic genera Nodobairdia Kollmann, 1963 and Mirabairdia Kollmann, 1963. In Triebelina indopacifica van den Bold, 1946, we describe an unexpected system of double pore canals, so far unknown in ostracods. We confirm that pore systems in Triebelina have largely intramural positions. In the Triassic Bairdiidae (Nodobairdia mammilata Kollmann, 1963 and Mirabairdia pernodosa Kollmann, 1963), we recognize simple unrimmed and massively nodular pores as well as marginal pores. Lateral normal pores of the Triassic specimens appear to be mostly in intra-solum positions. Although still exploratory and at the limits of the tomographic resolution, these observations provide new evidence to reject the formerly proposed synonymy of Triassic genera with Triebelina, which obstructed the establishment of a phylogenetic classification.
Ključne besede: ostracods, ornate Bairdiidae, morphology, normal pore canals, CT-scan, 3D analysis
Objavljeno v DiRROS: 08.03.2024; Ogledov: 127; Prenosov: 98
Celotno besedilo (10,78 MB)
Gradivo ima več datotek! Več... |
30. Roles of the reference service life (RSL) of buildings and the RSL of building components in the environmental impacts of buildingsTajda Potrč Obrecht, Roman Kunič, Sabina Jordan, Andraž Legat, 2019, objavljeni znanstveni prispevek na konferenci Povzetek: The Life Cycle Assessment of a building is a complex analysis that also involves the use of the predicted Reference Service Life (RSL) of the building components and materials, as well as the predicted RSL of the whole building. The RSL values of individual materials and building components can be obtained from different sources and are not exactly comparable. In the present study, the influence of selected RLS values on an LCA assessment was evaluated. Three different RSL databases were used as the sources of the data to estimate the environmental impacts of selected building components (internal wooden door and external finishing coat). Two scenarios were presented. In the first scenario a building component can be reused in another building, while in the second scenario the reuse of the building component is not possible. The study showed that dependent on the selected RSL database, the results can differ by up to a factor of five. Therefore, it is very important to describe clearly the maintenance scenarios for a building in order to have a reliable comparison of the results of LCA assessments.
Ključne besede: reference service life, life cycle assessment, refurbishment
Objavljeno v DiRROS: 08.03.2024; Ogledov: 125; Prenosov: 105
Celotno besedilo (2,89 MB)
Gradivo ima več datotek! Več... |
