1571. Carbonation of lightweight alkali-activated aggregates based on biomass fly ash : effect on microstructure and leaching behaviorAnže Tesovnik, Ottosen Lisbeth M., Vilma Ducman, 2025, izvirni znanstveni članek Povzetek: Artificial aggregates offer a sustainable solution to large-scale waste utilization and the increasing demand for limited natural aggregates. This study extends the understanding of the production of artificial lightweight aggregates with a variable rotation speed approach based solely on biomass fly ash (BFA) alkali-activated materials (AAMs). Systematic variation of alkali content and solution density at a constant water-to-solids ratio showed that alkali concentration significantly influences granulation beyond what can be explained by water availability. The interplay between alkali activation and carbonation was investigated using different mix designs and curing conditions, as well as comparing simultaneous curing carbonation with post-cure carbonation. The results were evaluated with regard to the effects on the macro- and microstructural properties as well as on the leaching behavior. Prolonged carbonation initiated after aggregate formation resulted in premature depletion of Ca, limiting the development of C-A-S-H gels and increasing microporosity, leading to a reduction in mechanical properties. In contrast, post-curing carbonation maintained a compressive strength of over 1 MPa while still allowing carbonation benefits, resulting in compressive strengths comparable to lightweight expanded clay aggregates. Carbonation also proved to be an effective leaching mitigation strategy by stabilizing heavy metals through both physical encapsulation and chemical pH regulation. These results underline the importance of carbonation timing in high Ca AAMs and highlight lightweight aggregates as a viable pathway for BFA valorization, CO₂ sequestration and sustainable construction applications. This approach offers an alternative valorization strategy for BFA facing regulatory restrictions for direct use in cement, while contributing to carbon capture and circular economy initiatives.
Ključne besede: artificial aggregates, lightweight aggregates, biomass ash, alkali-activated materials, leaching, carbonation
Objavljeno v DiRROS: 18.07.2025; Ogledov: 461; Prenosov: 478
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1572. Raba števniških zgradb z dvoj- v slovenščiniMladen Uhlik, Andreja Žele, 2024, izvirni znanstveni članek Ključne besede: slovenščina, števnik, ločilni števnik, števniške zgradbe, družljivost, ujemanje, neujemanje
Objavljeno v DiRROS: 17.07.2025; Ogledov: 328; Prenosov: 188
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1574. Convex geometries yielded by transit functionsManoj Changat, Lekshmi Kamal K. Sheela, Iztok Peterin, Ameera Vaheeda Shanavas, 2025, izvirni znanstveni članek Povzetek: Let $V$ be a finite nonempty set. A transit function is a map $R:V\times V\rightarrow 2^V$ such that $R(u,u)=\{u\}$, $R(u,v)=R(v,u)$ and $u\in R(u,v)$ holds for every $u,v\in V$. A set $K\subseteq V$ is $R$-convex if $R(u,v)\subset K$ for every $u,v\in K$ and all $R$-convex subsets of $V$ form a convexity $\mathcal{C}_R$. We consider the Minkowski-Krein-Milman property that every $R$-convex set $K$ in a convexity $\mathcal{C}_R$ is the convex hull of the set of extreme points of $K$ from axiomatic point of view and present a characterization of it. Later we consider several well-known transit functions on graphs and present the use of the mentioned characterizations on them.
Ključne besede: Minkowski-Krein-Milman property, convexity, convex geometry, transit function
Objavljeno v DiRROS: 17.07.2025; Ogledov: 331; Prenosov: 220
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1575. Menopavza in metabolni sindromKristina Groti Antonič, 2025, pregledni znanstveni članek Povzetek: Metabolni sindrom je skupek povezanih kliničnih in presnovnih dejavnikov, ki napovedujejo tveganje za nastanek sladkorne bolezni tipa 2 in srčno-žilne bolezni. Metabolni sindrom vključuje visceralno debelost, moteno presnovo glukoze, aterogeno dislipidemijo in arterijsko hipertenzijo. Povečana prevalenca metabolnega sindroma v menopavzi je posledica izgube proaktivne vloge estrogenov in povečanih koncentracij androgenov v obtoku, kar povzroči porazdelitev telesne maščobe in razvoj visceralne debelosti. Metabolni sindrom lahko vpliva tudi na tveganje za nastanek raka endometrija in dojke, osteoporoze, kronične ledvične bolezni, srčno-žilnih zapletov ter zmanjšanja kakovosti življenja v menopavzi. Načrtovano hujšanje, omejitev kalorij in telesna aktivnost so povezani z zmanjšanim tveganjem za bolezni endometrija. Poleg sprememb življenjskega sloga se lahko v primeru odsotnosti kontraindikacij predpiše zdravilo metformin, ki zmanjšuje metabolni sindrom, znižuje raven inzulina pri ženskah po menopavzi in je močan zaviralec proliferacije rakavih celic endometrija. Še vedno pa je pri obvladovanju simptomov in nekaterih posledic menopavze najučinkovitejše hormonsko nadomestno zdravljenje.
Ključne besede: debelost, menopavza, metabolni sindrom, metformin, sladkorna bolezen tipa 2
Objavljeno v DiRROS: 17.07.2025; Ogledov: 462; Prenosov: 151
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1576. Total ▫$k$▫-coalition: bounds, exact values and an application to double coalitionBoštjan Brešar, Sandi Klavžar, Babak Samadi, 2025, izvirni znanstveni članek Povzetek: Let $G=\big{(}V(G),E(G)\big{)}$ be a graph with minimum degree $k$. A subset $S\subseteq V(G)$ is called a total $k$-dominating set if every vertex in $G$ has at least $k$ neighbors in $S$. Two disjoint sets $A,B\subset V(G)$ form a total $k$-coalition in $G$ if none of them is a total $k$-dominating set in $G$ but their union $A\cup B$ is a total $k$-dominating set. A vertex partition $\Omega=\{V_{1},\ldots,V_{|\Omega|}\}$ of $G$ is a total $k$-coalition partition if each set $V_{i}$ forms a total $k$-coalition with another set $V_{j}$. The total $k$-coalition number ${\rm TC}_{k}(G)$ of $G$ equals the maximum cardinality of a total $k$-coalition partition of $G$. In this paper, the above-mentioned concepts are investigated from combinatorial points of view. Several sharp lower and upper bounds on ${\rm TC}_{k}(G)$ are proved, where the main emphasis is given on the invariant when $k=2$. As a consequence, the exact values of ${\rm TC}_2(G)$ when $G$ is a cubic graph or a $4$-regular graph are obtained. By using similar methods, an open question posed by Henning and Mojdeh regarding double coalition is answered. Moreover, ${\rm TC}_3(G)$ is determined when $G$ is a cubic graph.
Ključne besede: total k-coalition, total k-domination, regular graph, double coalition
Objavljeno v DiRROS: 17.07.2025; Ogledov: 427; Prenosov: 223
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1577. Stone products of the Roman municipium of Neviodunum, Pannonia (modern Drnovo, Slovenia)Katharina Zanier, Rok Brajkovič, Luka Gale, Matevž Novak, 2025, izvirni znanstveni članek Povzetek: The paper presents the lithologies used in the stone products of Neviodunum (modern Drnovo in Slovenia), a Roman municipium in south-western Pannonia. For this purpose, 95 stone monuments were assessed. Petrographic and biostratigraphic analyses were carried out on 56 archaeological and 57 geological samples. Our research shows that, besides some rare exceptions, most stone products refer to three lithostratigraphic units: the Middle Miocene ‘Lithothamnium’ Limestone Member of the Laško Formation, the Upper Cretaceous Krško Formation and the Early Jurassic Krka Limestone Member of the Podbukovje Formation.
Ključne besede: biostratigraphic analysis, petrographic analysis, Roman period, Slovenia, stone monuments, stone provenience
Objavljeno v DiRROS: 17.07.2025; Ogledov: 411; Prenosov: 174
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1578. Integrated analysis of olive mill wastewaters : physicochemical profiling, antifungal activity, and biocontrol potential against BotryosphaeriaceaeElena Petrović, Karolina Vrandečić, Alen Albreht, Igor Gruntar, Nikola Major, Jasenka Ćosić, Zoran Užila, Smiljana Goreta Ban, Sara Godena, 2025, izvirni znanstveni članek Ključne besede: antagonism, Bacillus velezensis, biological control, phenols, yeast
Objavljeno v DiRROS: 17.07.2025; Ogledov: 394; Prenosov: 253
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1579. Paleoecology of Early Ladinian low-diversity radiolarian fauna from Mt. Svilaja (External Dinarides, Croatia)Špela Goričan, Tea Kolar-Jurkovšek, Dunja Aljinović, Tamara Troskot-Čorbić, Bogdan Jurkovšek, 2025, izvirni znanstveni članek Povzetek: Dark-grey cherty limestone from Mt. Svilaja contains moderately well-preserved radiolarians of unusually low diversity. Nineteen genera were encountered, namely, only one fourth of genera known from the time equivalent Buchenstein Formation. Based on conodonts, the studied interval is assigned to the Lower Ladinian Budurovignathus hungaricus Zone. Ammonoids and allochthonous fossil elements (calcareous algae, corals, brachiopods, bivalves, benthic foraminifera, terrestrial-plant remains) from the same interval were previously reported. Facies and organic-matter analyses support the interpretation of depositional setting in a semi-enclosed basin with oxygen-deficient bottom waters. The radiolarian assemblage consists of spherical Entactinaria (Pentactinocarpidae, Heptacladidae, Hindeosphaeridae) and Spumellaria (Archaeocenosphaera, Paurinella, Triassospongosphaera, Spongopallium), and monocyrtid Nassellaria (mostly Hozmadia). Among Pentactinocarpidae, Lobactinocapsa ellipsoconcha Dumitrica is abundant and characterized by considerable variability of the cortical shell regarding its shape (ovoid to spherical), wall thickness (single-layered to spongy), and number of external spines. Eptingiidae, Oertlispongidae, Relindellidae, and all multicyrtid Nassellaria, common in the Buchenstein Formation as well as in radiolarian cherts associated with ophiolites, are missing. Similar, although less drastically reduced radiolarian fauna is known from the coeval San Giorgio Dolomite, which was also deposited in an oxygen-deficient intra-platform basin. The San Giorgio fauna lacks multicyrtid Nassellaria but still contains abundant Eptingiidae, Oertlispongidae, and Relindellidae. The likely factor reducing the diversity in the intra-platform basins was the vertical extent of the oxygen-deficient lower water column. Only surface-dwelling radiolarians were successful in stratified basins with expanded deep-water hypoxia.
Ključne besede: Radiolaria, Conodonts, Middle Triassic, Anoxic intra-platform basin, Dinarides
Objavljeno v DiRROS: 17.07.2025; Ogledov: 438; Prenosov: 191
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