1. Evaluation of fly ash-based alkali activated foams at room and elevated temperaturesKatja Traven, Mark Češnovar, Srečo D. Škapin, Vilma Ducman, 2020, objavljeni znanstveni prispevek na konferenci Povzetek: Alkali activated materials (AAM) are, in their broadest classification, any binder systems derived by the reaction of an alkali metal source (silicates, alkali hydroxides, carbonates , sulphates) with a solid, amorphous alumosilicate powder (found in precursors such as slag, fly ash and bottom ash). A wide variety of products can be obtained by the alkali activation process and could replace traditional construction products. Among the se, alkali activated foams (AAF) represent one of the most promising materials, owing to their economically accessible alumosilicate rich source materials, including industrial waste materials, clean processing, higher added value and most importantly, pro ducts with competitive properties. In the present study, the properties of alkali activated fly ash - based foam materials were studied at room temperature as well as at elevated temperatures (up to 1200 °C ) in order to develop a durable material in terms o f mechanical properties and suitability for high temperature applications. Ključne besede: lightweight porous insulating material, alkali activated materials, microstructural analysis Objavljeno v DiRROS: 05.03.2024; Ogledov: 80; Prenosov: 36 Celotno besedilo (970,74 KB) Gradivo ima več datotek! Več... |
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3. The role of relative humidity on crystallization of calcium carbonate from calcium acetoacetate precursorAndreja Pondelak, Francesca Rosi, Celeste Maurich, Costanza Miliani, Srečo D. Škapin, Andrijana Sever Škapin, 2019, izvirni znanstveni članek Povzetek: Calcium acetoacetate, Ca(OAcAc)2, was exposed 7, 30 and 365 days to different values of relative humidity (33%, 48%, 75% and 96%) at 40 °C in order to study its transformation to CaCO3. The resulting Ca(OAcAc)2 decomposition and the time dependence of the phase transformations were monitored and critically evaluated by Fourier transform infrared spectroscopy, field emission scanning electron microscopy and X-ray powder diffraction. The impact of relative humidity on CaCO3 polymorph formation was thoroughly assessed. In all of the conditions used and for all ageing periods, the formed crystal structure is found to be vaterite. At the lowest relative humidity (33%), the amorphous CaCO3 remains more or less almost untransformed even after one year of exposure. It is proposed that the reason for the stability of amorphous CaCO3 is due to the limited amount of physisorbed water on the surfaces of the particles, which is considered the driving force for its transformation. However, the carbonation process is faster in the case of the highest humidity (96%). The findings are not only important for better solutions in the field of cultural heritage, but also shed new light on the fundamental mechanism of CaCO3 crystallization. Ključne besede: calcium acetoacetate, relative humidity, carbonation, amorphous carbonate, vaterite, mechanism Objavljeno v DiRROS: 22.11.2023; Ogledov: 259; Prenosov: 122 Celotno besedilo (6,55 MB) Gradivo ima več datotek! Več... |
4. High temperature resistant fly-ash and metakaolin-based alkali-activated foamsKatja Traven, Mark Češnovar, Srečo D. Škapin, Vilma Ducman, 2021, izvirni znanstveni članek Povzetek: Alkali-activated foams (AAFs) present one of the most promising materials for use in the construction sector. Their main advantages lie in their utilization of waste material and their ability to form at temperatures well below 100 °C, while still competing in performance with foamed glass or ceramics. The present body of research has focused on improving the thermal stability of fly-ash foams by i) adding metakaolin, and ii) changing the activator from sodium-based to potassium-based components. It has been confirmed that a certain increase in thermal resistance is achieved through the addition of metakaolin while changing activators played a crucial role. While sodium-based AAFs without metakaolin start to shrink at approximately 600 °C, samples that have had metakaolin added start to shrink at approximately 700 °C. Samples without metakaolin that have used a potassium activator start to shrink at approximately 800 °C, whereas potassium-based samples with the addition of metakaolin start to shrink at approximately 900 °C. Ključne besede: alkali activated materials, geopolymers, high temperature, resistance, foams Objavljeno v DiRROS: 01.08.2023; Ogledov: 229; Prenosov: 170 Celotno besedilo (13,91 MB) Gradivo ima več datotek! Več... |
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6. Slovenska priporočila za obravnavo odraslih bolnikov s kronično odpovedjo prebavilNada Rotovnik-Kozjek, Tajda Božič, Katja Kogovšek, Borut Štabuc, Laura Petrica, Karla Berlec, Nataša Puzić Ravnjak, Erik Brecelj, Aleš Tomažič, Sanela Banović, Rada Franko, Milena Kovač-Blaž, Janez Breznik, Davorin Ćeranić, David Drobne, Mojca Gašperin, Tomaž Jurca, Maja Ebert Moltara, Rado Janša, Marjana Turk Jerovšek, Taja Jordan, Tina Kamhi, Primož Karner, Milena Kerin-Povšič, Neža Majdič, Denis Mlakar-Mastnak, Andreja Ocepek, Tadeja Pintar, Stojan Potrč, Nataša Smrekar, Monika Sonc, Maja Šeruga, Petra Tavčar, Igor Virant, 2021, strokovni članek Ključne besede: kronična odpoved prebavil, zdravljenje, onkološko zdravljenje Objavljeno v DiRROS: 11.06.2021; Ogledov: 1283; Prenosov: 343 Celotno besedilo (135,03 KB) |
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8. Go for Mura : upravljanje poplavnih gozdov v območjih Natura 2000 ob MuriŠpela Ambrožič, Gregor Božič, Maarten De Groot, Andreja Ferreira, Tatjana Gregorc, Marjana Hönigsfeld Adamič, Anže Japelj, Andrej Kapla, Marko Kovač, Štefan Kovač, Lado Kutnar, Tom Levanič, Boštjan Mali, Aleksander Marinšek, Zdenka Mazej, Nikica Ogris, Špela Planinšek, Mitja Skudnik, Gabrijela Triglav Brežnik, Saša Vochl, Al Vrezec, 2017, strokovna monografija Povzetek: Vsebina publikacije na kratko povzema izsledke projekta Go for Mura. Predstavljeni so poplavni in močvirni gozdovi ob Muri, njihov pomen ter različni vidiki omenjenih gozdov, ki so bili raziskani tekom projekta. Predstavljene so ostale aktivnosti projekta . Ključne besede: Natura 2000, gospodarjenje, poškodovanost gozdov, poplavni gozd, Slovenija Objavljeno v DiRROS: 18.01.2021; Ogledov: 1532; Prenosov: 447 Celotno besedilo (2,27 MB) |
9. Decision support tool for the management of dynamic genetic conservation unitsA. Rudow, Marjana Westergren, J. Buiteveld, Václav Buriánek, B. Cengel, Joan Cottrell, G. de Dato, K. Järve, Davorin Kajba, Colin Kelleher, François Lefèvre, M. Liesebach, L. Nagy, Srđan Stojnić, M. Villar, L. Yrjänä, Michele Bozzano, 2020, končno poročilo o rezultatih raziskav Ključne besede: decision support tool, genetic conservation Objavljeno v DiRROS: 14.01.2021; Ogledov: 1117; Prenosov: 523 Celotno besedilo (2,92 MB) Gradivo ima več datotek! Več... |
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