1831. Dynamic properties of lightweight foamed glass and their effect on railway vibrationStanislav Lenart, Amir M. Kaynia, 2019, original scientific article Abstract: Deformation properties of lightweight coarse grained material from recycled foamed glass have been determined from large-scale triaxial tests on prismatic specimens with dimensions 40 cm x 40 cm x 80 cm. Deformations were measured locally using vertical and horizontal local deformation transducers. Monotonic and cyclic loading at small to medium strain range were conducted. Three load sequences representing the expected conditions of use of lightweight material as vibration-reducing material in railway geotechnics have been used. Results indicate strong effect of brittle cellular structure of tested material as well as confining pressure dependency of elastic threshold shear strain and damping ratio. The results were used to assess the applicability of empirical formulas for shear modulus of granular materials to lightweight foamed glass. The parameters determined from the laboratory tests were further used in numerical analysis of railway dynamic response. The results of the numerical simulations show that replacement of fill in track embankment by lightweight material could improve the dynamic response of the track in reducing the vibration.
Keywords: lightweight material, recycled foamed glass, railway vibration, shear modulus, damping
Published in DiRROS: 16.11.2023; Views: 431; Downloads: 298
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1832. Corrosion properties of aluminized 16Mo3 steelBlaž Karpe, Klara Prijatelj, Milan Bizjak, Tadeja Kosec, 2023, original scientific article Abstract: Chromium-molybdenum steel (16Mo3) is widely used in petroleum, gas, automotive, and construction industries due to its good oxidation resistance and mechanical properties at moderately elevated temperatures. The aim of the research was to evaluate the corrosion susceptibility of 16Mo3 steel in hot rolled and aluminized states. Aluminization was performed by diffusion pack aluminization process at 900°C/2h and 730°C/4h, respectively. Electrochemical corrosion testing included measuring open circuit potential (EOCP), linear polarization resistance (LPR), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) in potassium phosphate buffer (KH2PO4, pH = 7). Optical microscopy (OM), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) were used for surface layer microstructure characterization before and after corrosion tests. It was demonstrated that corrosion resistance of aluminized steel increased substantially. Corrosion properties were related to the structure and properties of intermetallic phase (FeAl, FeAl2 and Fe2Al5) that formed on the surface of 16Mo3 steel.
Keywords: aluminide coatings, aluminized steel, aluminizing, electrochemical corrosion investigation, 16Mo3 steel
Published in DiRROS: 16.11.2023; Views: 452; Downloads: 235
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1833. Accounting for cloud cover and circannual variation puts the effect of lunar phase on deer–vehicle collisions into perspectiveJacopo Cerri, Laura Stendardi, Elena Bužan, Boštjan Pokorny, 2023, original scientific article Abstract: Although several studies have focused on the influence of moonlight on deer–vehicle collisions, findings have been inconsistent. This may be due to neglect of the effects of cloud cover, a major impediment to moon illumination and circannual variation in both deer and human activity. We assessed how median cloud cover interacted with the illuminated fraction of the moon in affecting daily roe deer (Capreolus capreolus) roadkill in Slovenia (Central Europe). Data included nationwide roadkill (n = 49,259), collected between 2010 and 2019 by hunters, as required by law. Roadkill peaked under medium to high cloud cover and decreased during nights with low or extremely high cloudiness. This pattern was more pronounced on nights with a full moon. However, the effects of moon illumination and cloud cover had a lower predictive potential than circannual variation, as collisions clearly peaked in April/May, July and August/September. Our results suggest that moonlight could influence roe deer movements through compensatory foraging. However, on nights with a full moon, collisions could also be affected by weather. On bright nights, roe deer might be less active due to increased human presence and sustained vehicular traffic. Then, with medium to high cloud cover and also rainfall, human presence in the environment may be low enough to increase deer movements, but vehicular traffic can still be intermediate, maximizing the risk of collisions. Finally, with overcast skies, widespread rainfall can reduce both traffic volume and human outdoor activity, decreasing the risk of collisions. Moon illumination may indeed affect wildlife–vehicle collisions and roadkill, but its effects should be quantified as a function of cloud cover. Moreover, to make studies truly comparable, research about wildlife–vehicle collisions should also account for time of the year. Policy implications. Because collisions with roe deer peak at particular periods of the year, signs should be installed seasonally. By doing so, they would warn drivers about the risk, improve drivers' awareness and increase their safety. Moreover, as collisions also increase on nights with a full moon and overcast skies, interactive warning signs that are activated by ground illumination should also be useful.
Keywords: cloudiness, MODIS Surface Reflectance, moon, road ecology, roe deer, Slovenia, thin-plate splines, wildlife–vehicle collisions
Published in DiRROS: 16.11.2023; Views: 532; Downloads: 231
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1834. Monitoring the galvanic corrosion of copper–steel coupling in bentonite slurry during the early oxic phase using coupled multielectrode arraysTadeja Kosec, Miha Hren, Klara Prijatelj, Bojan Zajec, Nina Gartner, Andraž Legat, 2023, original scientific article Abstract: In the case of a two-part container for spent nuclear fuel, consisting of an iron-based inner structure with a copper coating, the potential perforation of copper through minor damage may result in intensive galvanic corrosion between copper and steel. The present work focuses on the corrosion of steel galvanically coupled to copper and exposed to a slightly saline environment under oxic conditions. The electrochemical processes on individual electrodes were monitored by coupled multielectrode arrays (CMEAs). The CMEAs were either in contact with groundwater saturated with bentonite or immersed in groundwater only. Very high galvanic corrosion currents were detected between carbon steel and pure copper in the early oxic phase. Additionally, the use of CMEAs further made it possible to monitor the distribution of cathodic currents around the steel electrode, which behaved anodically. Various microscopy and spectroscopy techniques were applied to identify the modes of corrosion and the type of corrosion products present at the end of the period of exposure.
Keywords: copper, steel, bentonite, Aspö groundwater, coupled multi electrode array, electrochemical properties, Raman analysis, corrosion
Published in DiRROS: 16.11.2023; Views: 550; Downloads: 124
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1836. Finančno vrednotenje proizvodnje v semenarstvu in drevesničarstvu ter potreben obseg investicij za širitev dejavnosti : CRP V4-2015 - Poslovne priložnosti v gozdnem semenarstvu in drevesničarstvuTjaša Baloh, Natalija Dovč, Boris Rantaša, Hojka Kraigher, 2023, treatise, preliminary study, study Keywords: gozdni reprodukcijski material, sadike, semena, klasična proizvodnja sadik, kontejnerska proizvodnja sadik, stroški
Published in DiRROS: 15.11.2023; Views: 525; Downloads: 144
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1837. Smernice za zagotavljanje gozdnega reprodukcijskega materiala : predlog pripravljen v okviru projekta LIFEGENMONKristina Sever, Boris Rantaša, Marijana Vidrih Minić, Natalija Dovč, Janez Kermavnar, Marjana Westergren, Gregor Božič, Matjaž Guček, Andrej Breznikar, Aleš Poljanec, Hojka Kraigher, 2021, treatise, preliminary study, study Keywords: gozdni reprodukcijski material, gozdni semenski objekti, provenienčna območja, vrste, genetska pestrost
Published in DiRROS: 14.11.2023; Views: 570; Downloads: 170
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1838. PrefaceVasja Leban, Anže Japelj, Lidija Zadnik Stirn, Špela Pezdevšek Malovrh, 2023, preface, editorial, afterword Keywords: forest management, economics, conferences, preface
Published in DiRROS: 14.11.2023; Views: 627; Downloads: 189
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