11. Additive manufacturing multi-material components of SAF 2507 duplex steel and 15-5 PH martensitic stainless steelMartina Koukolíková, Pavel Podaný, Sylwia Rzepa, Michal Brázda, Aleksandra Kocijan, 2023, original scientific article Abstract: The study reports the successful deposition of 15–5 precipitation-hardened (PH) martensitic steel on SAF 2507 duplex stainless steel (and vice versa) to form functionally graded materials (FGMs) using powder-based, directed-energy-deposition (DED) technology. The evolution of the microstructure and the mechanical properties of the 15–5 PH/SAF 2507 functionally graded material in the as-built state were investigated systematically. The results proved that the microstructural transition zone (MTZ) is formed above the fusion line due to the dilution effect of both steels. The phase composition of the MTZ consists of ferrite and, in comparison to the base materials, an increased amount of austenite. The interface has the lowest hardness owing to the formation of a significant proportion of the austenitic phase. However, the tensile mechanical properties were not affected by the interface as failure occurred in both SAF 2507 and at the interface regions. The research presents a promising application of FGMs in a horizontal configuration to form a high - quality, metallurgical joint between heterogeneous materials. This study introduces a novel approach by additive manufacturing (AM) of heterogeneous multi-materials, merging the favorable properties of duplex SAF 2507 and martensitic 15-5 PH stainless steels through superior metallurgical bonding. The combination of SAF 2507 and 15-5 PH in a functionally graded material has not been previously explored, as the existing studies deal with the duplex stainless steels SAF 2507 and either martensitic stainless-steel 15-5 PH deposited separately by laser powder-bed-fusion (L-PBF) or DED methods. This research pioneers the investigation of these materials in tandem, paving the way for the development of novel FGMs with optimized properties for specific applications. The resulting FGM exhibits exceptional corrosion resistance and high strength, making it highly versatile for applications in diverse industries such as offshore oil and gas production, aerospace, aviation, and chemical processing equipment.
Keywords: directed energy deposition, functionally graded materials, miniaturized specimen testing methods, SAF 2507, 15-5 PH
Published in DiRROS: 04.04.2024; Views: 107; Downloads: 44
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12. Keep it simple : improving the ex situ culture of Cystoseira s.l. to restore macroalgal forestsAna Lokovšek, Valentina Pitacco, Domen Trkov, Leon Lojze Zamuda, Annalisa Falace, Martina Orlando-Bonaca, 2023, original scientific article Abstract: Brown algae from genus Cystoseira s.l. form dense underwater forests that represent the most productive areas in the Mediterranean Sea. Due to the combined effects of global and local stressors such as climate change, urbanization, and herbivore outbreaks, there has been a severe decline in brown algal forests in the Mediterranean Sea. Natural recovery of depleted sites is unlikely due to the low dispersal capacity of these species, and efficient techniques to restore such habitats are needed. In this context, the aims of our study were (1) to improve and simplify the current ex situ laboratory protocol for the cultivation of Gongolaria barbata by testing the feasibility of some cost-effective and time-efficient techniques on two donor sites of G. barbata and (2) to evaluate the survival and growth of young thalli during the laboratory phase and during the most critical five months after out-planting. Specifically, the following ex situ cultivation methods were tested: (A) cultivation on clay tiles in mesocosms with culture water prepared by three different procedures (a) filtered seawater with a 0.22 μm filter membrane, (b) filtered seawater with a 0.7 μm filter membrane (GF), and (c) UV-sterilized water, and (B) cultivation on clay tiles in open laboratory systems. After two weeks, all thalli were fixed to plastic lantern net baskets suspended at a depth of 2 m in the coastal sea (hybrid method), and the algal success was monitored in relation to the different donor sites and cultivation protocol. The satisfactory results of this study indicate that UV-sterilized water is suitable for the cultivation of G. barbata in mesocosm, which significantly reduces the cost of the laboratory phase. This opens the possibility of numerous and frequent algal cultures during the reproductive period of the species. Additionally, if the young thalli remain in the lantern net baskets for an extended period of several months, they can grow significantly in the marine environment without being exposed to pressure from herbivorous fish.
Keywords: gojenje ex situ, obnova habitata, izboljšanje metodologije, gozdički rjavih alg, ex situ cultivation, mesocosm, open system, method improvement, brown algal forests restoration
Published in DiRROS: 29.03.2024; Views: 154; Downloads: 92
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14. Seismogenic depth and seismic coupling estimation in the transition zone between Alps, Dinarides and Pannonian Basin for the new Slovenian seismic hazard modelPolona Zupančič, Barbara Šket Motnikar, Michele M. C. Carafa, Petra Jamšek Rupnik, Mladen Živčić, Vanja Kastelic, Gregor Rajh, Martina Čarman, Jure Atanackov, Andrej Gosar, 2024, original scientific article Abstract: Seismogenic depth and seismic coupling are important inputs into seismic hazard estimates. Although the importance of seismic coupling is often overlooked, it significantly impacts seismic hazard results. We present an estimation of upper and lower seismogenic depth and expected hypocentral depth and seismic coupling in the transition zone between the Alps, Dinarides and Pannonian Basin, characterized by a complex deformation pattern, highly variable crustal thickness, and moderate seismic hazard, supporting the development of the 2021 seismic hazard model of Slovenia. The hazard model was based on three seismic source models: area source model, fault source model and smoothed seismicity (point) source model. We estimated the lower seismogenic depth using seismological and geological data and compared them. The seismological estimate was based on two regional earthquake catalogues prepared for this study. In the area source model, estimates of lower seismogenic depth from seismological data are deeper or equal to the ones derived from geological data, except in one case. In the fault source model, we analysed each fault individually and chose seismological lower depth estimates in 12 among 89 faults as more representative. The seismogenic thickness for each individual fault source was determined for seismic coupling determination. The seismic coupling was assessed by two approaches, i.e. we chose the most trusted value from the literature, and the value determined for each fault individually by using the approach based on the updated regional fault and earthquake data sets. The final estimate of seismic coupling ranges from 0.77 to 0.38. We compared the tectonic moment rate based on long-term slip rate using different values of seismic coupling with the seismic moment rate obtained from the earthquake catalogue. The analysis is done for the whole area, as well as for the individual area zones. The analysis of N–S components of estimated slip for the largest faults in the area of west Slovenia shows that the regional geological and geodetic shortening rates are comparable. The total activity rate of three global seismic source models is compared, which gives up to a 10 % difference. Our results contribute to a better understanding of the seismic activity in the region. The presented approach for seismic coupling estimation can be applied in cases where the total slip rate is given instead of its seismic part and can be used at regional or national level. The approach is also suitable for the cross-border harmonization of the European seismic hazard modelling data.
Keywords: seismic hazard, modeling, Slovenia
Published in DiRROS: 18.03.2024; Views: 249; Downloads: 278
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15. Efficacy of first-line systemic treatment in correlation with BRAF V600E and different KRAS mutations in metastatic colorectal cancer : a single institution retrospective analysisMartina Reberšek, Marko Boc, Petra Škerl, Jernej Benedik, Zvezdana Hlebanja, Neva Volk, Srdjan Novaković, Janja Ocvirk, 2011, original scientific article Keywords: rak (medicina), debelo črevo, danka, zdravljenje
Published in DiRROS: 18.03.2024; Views: 102; Downloads: 37
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17. Cisplatin-induced non-convulsive posterior reversible encephalopathy syndrome in a 41-year-old woman with metastatic malignant melanomaJanja Ocvirk, Marko Boc, Martina Reberšek, Tanja Roš-Opaškar, 2009, original scientific article Abstract: Background. Cisplatin, a widely used antineoplastic agent usually induces peripheral neuropathy, but can rarely also complicate with encephalopathy, with or without seizures. Case report. We report a case of a young patient with metastatic malignant melanoma with signs and symptoms of cisplatin-induced non-convulsive posterior reversible encephalopaty syndrome. Within the days shortly after the first cycle of cisplatin based chemotherapy the patient suffered from nausea, vomitus, headache, severe pain at the site of sub-cutaneous metastases and confusion. She later experienced somnolence, cortical blindness and aphasia, but without epileptic seizures. Conclusions. Cisplatin is an effective chemotherapeutic drug but also very toxic one and physicians using it must also be aware of possible encephalopathy.
Published in DiRROS: 08.03.2024; Views: 147; Downloads: 41
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19. DNA quadruplex structure with a unique cation dependencyMartin Gajarský, Petr Stadlbauer, Jiří Šponer, Anne Cucchiarini, Michaela Dobrovolna, Vaclav Brazda, Jean-Louis Mergny, Lukáš Trantírek, Martina Lenarčič Živković, 2024, original scientific article Published in DiRROS: 07.03.2024; Views: 283; Downloads: 241
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