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Povzetek: The evolution of alluvial megafans has mainly been investigated in unconfined settings; however, at the boundary of these large depositional systems, the development of fluvial channels can be affected by structural constraints with regional extent. Here we present the study of the eastern sector of the megafan of Isonzo River, in the Gulf of Trieste, where this system fed through the southern Alps is constrained by the Karst and Istria cliffs. Although this area is now submerged under the northern Adriatic Sea, stratigraphy from seismo-acoustic profiles, drill cores and multi-beam bathymetry allows us to reconstruct the paleochannel system of the Isonzo River in detail, which was likely active within the period of 21–17.5 ka cal BP, at the end of LGM. This was reconstructed for over 50 km and currently represents the longest abandoned fluvial channel in the Mediterranean seabed. The occurrence of the mountain fringe and competition with nearby alluvial systems forced the paleochannel to follow the present coastline and conditioned the slope of its thalweg to decrease almost to null, resulting the transformation from the megafan to the undifferentiated alluvial plain.
Ključne besede: marine geology, CHIRP, stratigraphy, bathymetry, last glacial maximum, adriatic sea
Objavljeno v DiRROS: 31.05.2023; Ogledov: 360; Prenosov: 115
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Povzetek: The environmental properties of three geotechnical composites made by recycling wastes were investigated on a laboratory scale and in the field with the use of lysimeters designated for the revitalization of degraded mining sites. Composites were prepared by combining the mine waste with paper-mill sludge and foundry sand (Composite 1), with digestate from municipal waste and paper ash (Composite 2), and with coal ash, foundry slag and waste incineration bottom ash (Composite 3). The results of laboratory leaching tests proved that Composites 1 and 3 are envi- ronmentally acceptable, according to the legislative limits, as the potentially hazardous substances were immobilized, while in Composite 2, the legislative limits were exceeded. In the field lysimeters, the lowest rate of leaching was determined for optimally compacted Composites 1 and 3, while for Composite 2 the leaching of Cu was high. This study proved that optimally installed Composites 1 and 3 are environmentally acceptable for use in construction as an alternative to virgin materials, for the revitalization of degraded mining sites or, along with Composite 2, for closure operations with landfills. In this way, locally available waste streams are valorised and channelized into a beneficial and sustainable recycling practice.
Ključne besede: waste, recycling, lysimeter, potentiali hazardous substances, immobilization, revitalisation, environmental, open access
Objavljeno v DiRROS: 29.05.2023; Ogledov: 387; Prenosov: 286
Celotno besedilo (3,42 MB)
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Povzetek: Orthotic and prosthetic materials should have good mechanical and antibacterial properties. Therefore, in our study, we consider four common foamed closed-cells and two solid polymeric materials regarding their mechanical behaviour and tendency for bacterial adhesion. For all materials, the surface roughness, hydrophobicity, zeta potential, tensile properties, hardness and CIE color parameters were measured. We found that foamed polymeric materials have higher roughness, higher hydrophobicity, lower Young's modulus, lower maximum tensile strength and lower hardness than solid materials. Bacterial adhesion test measurements based on observation by scanning electron microscopy show much a lower adhesion extent of S. aureus on solid materials than on foamed materials. The measured biophysical properties could be the key data for users to select the optimal materials.
Ključne besede: surface characterization, bacterial adhesion, foamed materials, prosthetic and orthotic material, surfaces
Objavljeno v DiRROS: 22.05.2023; Ogledov: 338; Prenosov: 222
Celotno besedilo (3,14 MB)
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Povzetek: Pri nedrobnoceličnem raku pljuč (NDPR) so možganski zasevki prisotni v 30 do 44 %. Prognoza bolnikov z možganskimi (CŽS) zasevki je odvisna od različnih prognostičnih dejavnikov, ki vplivajo na odločitev o zdravljenju in posledično na dolžino preživetja. Glavni prognostični dejavniki so starost, telesna zmogljivost po Karnofskem, razširjenost bolezni zunaj CŽS in število zasevkov. Srednje preživetje za NDPR je glede na stopenjsko prognostično ocenjevalno lestvico z molekularnimi označevalci (Lung- molGPA) od 5 do 46 mesecev. Pri bolnikih s številnimi možganskimi zasevki je srednje preživetje krajše. Pri teh bolnikih je v prvi vrsti indicirano zdravljenje z obsevanjem cele glave. Pri boljši prognozi pride v poštev tudi obsevanje cele glave z dodatkom doze s stereotaktično radiokirurgijo (SRK) predvsem večjih zasevkov, ki povzročajo nevrološko simptomatiko.
Ključne besede: pljučni rak, onkološko zdravljenje, bolniki
Objavljeno v DiRROS: 12.05.2023; Ogledov: 430; Prenosov: 93
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Povzetek: Hybrid phenol-formaldehyde (PF) resins represent one of the most important niche groups of binding systems for composites. New industrial needs, environmental requirements, and price fluctuations have led to further research on materials with enhanced mechanical and thermal properties. The preparation of novel hybrid materials can be achieved by inclusion of various elements or functional groups in the organic polymer phenolic framework. Herein, we report the synthesis and characterization of a PF-based hybrid material with different nanoscale silicone species and ZnAl-layered double hydroxide (LDH). The main goals of this study were to improve the synthetic pathways of hybrid resin, as well as to prepare granulated composite materials and test samples and determine their characterization. Added inorganic species increased the glass-transition temperature by a minimum of 8 °C, which was determined using differential scanning calorimetry (DSC). Rheological properties (melting viscosity and flow distance) of the hybrid resin were measured. The homogeneity of distribution of added species across the organic matrix was evaluated with scanning electron microscopy (SEM). With synthesized new hybrid-binding systems, we prepared different granulated composite materials and evaluated them with the measurements of rheological properties (flow curing characteristics). Tensile strength of samples, prepared from granulated composite material, improved by more than 5%.
Ključne besede: phenol-formaldehyde hybrid resins, nano-SiO2, ZnAl-LDH, composites, glass-transition temperature, mechanical properties
Objavljeno v DiRROS: 03.05.2023; Ogledov: 436; Prenosov: 193
Celotno besedilo (1,92 MB)
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