Statistika DiRROS

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Opis: The nature reserve Mykhailivska Tsilyna is located in Sumy region, in the northern part of Forest-Steppe zone of Ukraine. The area of virgin northern meadow-steppe is protected there. A new, large-scale vegetation map (scale 1:10000) of the reserve (the first one in its new borders) had been created. The main units of mapping are complexes of plant communities in ranks of associations, subassociations and variants. In total, 27 such complexes and 10 units of another rank have been identified. The map shows vegetation cover changesover a period of strict protection (2011–2023). The most common classes of vegetation in the reserve are: Molinio-Arrhenatheretea, Artemisietea vulgarisandFestuco-Brometea. Main changes in the vegetation cover of the reserve’s old territory are manifested in the form of steppe transformation: from meadow-steppe areas to more mesic shrub-steppe with dominating Cytisus ruthenicus and forb communities with dominating Euphorbia semivillosa. In these communities can be seen a decrease in the share of tussock grasses and an increase in the share of rhizomatous grasses. The same process is occurring in the reserve’s new territory, but phytocenoses are different there.
Ključne besede: vegetation mapping, steppe vegetation, vegetation dynamics, problems of strict protection regime in the steppe
Objavljeno: 24.01.2026; Ogledov: 430; Prenosov: 883
Celotno besedilo (4,02 MB)
Prenosov v mesecu: 649

Opis: The phase composition and microstructure of Sr-hexaferrite (SFO) ceramics govern the hard magnetic properties. Here, pressureless spark plasma sintering (pSPS) technique was employed for the rapid consolidation (500°C/min) of SFO in a radiating graphite crucible under vacuum and, thus, reductive conditions. A numerical model depicting the temperature profile within the heating crucible was constructed to understand the temperature evolution within the samples. The combination pSPS sintering environment (graphite heating crucible under vacuum) promoted phase decomposition to Sr-enriched and depleted phases of various morphological variations, leading to reduction of hard magnetic properties. Notably, certain newly formed phases exhibited lower melting points, inducing a shift in the sintering mechanism from solid-state sintering to a partial liquid-phase sintering mechanism.
Ključne besede: pressureless spark plasma sintering, electronic ceramics, numerical simulations
Objavljeno: 03.09.2025; Ogledov: 801; Prenosov: 795
Celotno besedilo (11,24 MB)
Prenosov v mesecu: 462

Opis: Scour erosion continues to cause significant issues for the stability and lifespan of bridges worldwide. In Slovenia, extreme flooding in 2023 caused the collapse or failure of many bridges, primarily due to scour, which was exacerbated by debris accumulation. Despite advances in predicting and monitoring scour, it remains among the top reasons for the failure of bridges during flooding. Recent advances in vibration-based health monitoring suggest that scour erosion can be detected using methods such as changes in natural frequency, mode shapes, flexibility-based deflection, and other approaches using offline sensors such as passing vehicle responses. Many of these methods have been trialled numerically where scour is implemented as a reduction in the soil level (or stiffness) around a given bridge foundation. The most common way to model scour is to lower the soil level around a foundation, however, this ignores any contribution that the scour hole shape makes to the stiffness and strength of the soil beneath the scour hole. This paper investigates how the shape of scour holes influences the stiffness and strength of the remaining soil to understand the impact on the modal behaviour of a bridge. A numerical model of a bridge is developed where scour is implemented by removing Winkler springs from the model, and different scour hole shapes are considered in terms of how the remaining overburden influences the stiffness and strength of the soil springs. Scour hole shape properties are considered by means of varying the depth, width, and slope angle of the hole around a given foundation element. For the analyses in this paper, different scour hole shapes are implemented on an example bridge corresponding to local scour holes with narrow width; wider local scour holes; and general scour, where the full soil layer is removed (infinite width). The changes in the modal periods and mode shapes of the bridge in the traffic and river flow directions are assessed to understand the impact of the different scour types on the vibration characteristics.
Ključne besede: scour, dynamics, overburden, frequency, damage, bridges, scour hole shape
Objavljeno: 13.01.2026; Ogledov: 401; Prenosov: 696
Celotno besedilo (10,37 MB)
Prenosov v mesecu: 454

Opis: Recent field- and herbarium studies in the genus Abutilon in the Mediterranean and Macaronesia yielded some noteworthy results. The invasive South American weed A. grandifolium is reported for the first time from Algeria. A recent claim of A. grandiflorum from the Canary Islands is erroneous and referable to A. grandifolium. Historical records of the South African A. sonneratianum from Madeira are also discussed. This species is included in the list of invasive species in Portugal. However, it is shown that the invasive species in Portugal (Madeira) is A. grandifolium, not A. sonneratianum.
Ključne besede: Abutilon grandifolium, Algeria, Canary Islands, invasive plants, Madeira, new data, taxonomy
Objavljeno: 24.01.2026; Ogledov: 520; Prenosov: 694
Celotno besedilo (1,13 MB)
Prenosov v mesecu: 450

Ključne besede: kajenje, tobačni izdelki, bolezni, preventiva
Objavljeno: 21.05.2020; Ogledov: 3046; Prenosov: 1273
Celotno besedilo (129,65 KB)
Prenosov v mesecu: 447