1911. Grain size distribution of DP 600 steel using single-pass asymmetrical wedge testUrška Klančnik, Peter Fajfar, Jan Foder, Heinz Palkowski, Jaka Burja, Grega Klančnik, 2023, original scientific article Keywords: wedge test, hot-rolling, grain size distribution, dual-phase steel Published in DiRROS: 07.02.2024; Views: 397; Downloads: 158 Full text (4,64 MB) This document has many files! More... |
1912. Thermal fatigue degradation progress in SiMo ductile cast iron under oxidation conditionsMilan Terčelj, Jaka Burja, Goran Kugler, Primož Mrvar, 2023, original scientific article Keywords: metallurgical engineering, exhaust manifolds, cast irons, casting, microscopic characterization and microanalysis, thermal fatigue, material defect, microstructural control Published in DiRROS: 07.02.2024; Views: 435; Downloads: 248 Full text (36,47 MB) This document has many files! More... |
1913. An experimental study of liquid micro-jets produced with a gas dynamic virtual nozzle under the influence of an electric fieldBor Zupan, Gisel Esperanza Peña-Murillo, Rizwan Zahoor, Jurij Gregorc, Božidar Šarler, Juraj Knoška, Alfonso M. Gañán-Calvo, Henry N. Chapman, Saša Bajt, 2023, original scientific article Abstract: The results of an experimental study of micro-jets produced with a gas dynamic virtual nozzle (GDVN) under the influence of an electric field are provided and discussed for the first time. The experimental study is performed with a 50% volume mixture of water and ethanol, and nitrogen focusing gas. The liquid sample and gas Reynolds numbers range from 0.09–5.4 and 0–190, respectively. The external electrode was positioned 400–500 μm downstream of the nozzle tip and an effect of electric potential between the electrode and the sample liquid from 0–7 kV was investigated. The jetting parametric space is examined as a function of operating gas and liquid flow rates, outlet chamber pressure, and an external electric field. The experimentally observed jet diameter, length and velocity ranged from 1–25 μm, 50–500 μm and 0.5–10 m/s, respectively. The jetting shape snapshots were processed automatically using purposely developed computer vision software. The velocity of the jet was calculated from the measured jet diameter and the sample flow rate. It is found that micro-jets accelerate in the direction of the applied electric field in the downstream direction at a constant acceleration as opposed to the standard GDVNs. New jetting modes were observed, where either the focusing gas or the electric forces dominate, encouraging further theoretical and numerical studies towards optimized system design. The study shows the potential to unlock a new generation of low background sample delivery for serial diffraction measurements of weakly scattering objects. Keywords: micro jet, electric field, experimental study, flow focusing, Taylor cone, gas dynamic virtual nozzles Published in DiRROS: 07.02.2024; Views: 480; Downloads: 176 Full text (1,94 MB) This document has many files! More... |
1914. Metal artefacts and remains of armour from Kozlov Rob castle : metallurgical analyses as a tool for identification and interpretation of fragmentary archaeological findsJakob Kraner, Tomaž Lazar, Miha Mlinar, Jaka Burja, 2023, original scientific article Keywords: archaeology, castle, Kozlov Rob, Slovenia, armour, helmet, metallography Published in DiRROS: 07.02.2024; Views: 424; Downloads: 159 Full text (3,92 MB) This document has many files! More... |
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1916. Study on dissolution of Ba-containing inoculant in ductile cast iron melt and nucleation of graphiteMarica Tonkovič-Prijanovič, Primož Mrvar, Jaka Burja, Črtomir Donik, Mitja Petrič, 2023, original scientific article Keywords: inoculant, inoculant dissolving, reaction zone, phase composition, graphite nucleation, ductile cast iron, barium inoculant Published in DiRROS: 07.02.2024; Views: 313; Downloads: 178 Full text (17,37 MB) This document has many files! More... |
1917. An outbreak of Verticillium dahliae on sycamore maple in a forest stand in SloveniaAna Brglez, Zina Devetak, Nikica Ogris, Sebastjan Radišek, Barbara Piškur, 2024, original scientific article Abstract: Verticillium dahliae Kleb., the causal agent of Verticillium wilts, is a devastating plant disease affecting many plant species. Fungus V. dahliae was detected in a partially artificially established Acer pseudoplatanus L. forest stand in central Slovenia. This finding incited further study about the risk of different sources of V. dahliae isolates for maples in forests and the pathogenicity of three V. dahliae isolates of different origins was tested on saplings of A. pseudoplatanus, A. platanoides L., and A. campestre L. The inoculated saplings exhibited disease symptoms, i.e., leaf necrosis and wilting. At the end of the pathogenicity test, typical xylem browning was visible on the cross-sections, and the pathogen was successfully re-isolated. The isolates showed significant differences in their pathogenicity to specific maple hosts, with the agricultural isolate (originated from bell pepper) being the most aggressive on all three maple species. The disease severity index (DSI) and relative area under the disease progress curve (rAUDPC), as well as the success of re-isolation, indicate that A. platanoides is the most susceptible to inoculation with V. dahliae. In addition, significant differences in sapling biomass were observed between treated and control plants. These results suggest that maples in forest stands are threatened by V. dahliae, and biosecurity measures should be considered and implemented in forest management to reduce the transmission and potential spread of the pathogen. Keywords: Verticillium wilt, Acer spp., pathogenicity test, Disease severity index, DSI, Area under the disease progress curve, AUDPC, biosecurity Published in DiRROS: 07.02.2024; Views: 473; Downloads: 450 Full text (1,72 MB) This document has many files! More... |
1918. Small cellular particles from European spruce needle homogenateMarko Jeran, Anna Romolo, Vesna Spasovski, Matej Hočevar, Urban Novak, Roman Štukelj, Vid Šuštar, Matic Kisovec, Apolonija Bedina Zavec, Ksenija Kogej, Aleš Iglič, Polonca Trebše, Veronika Kralj-Iglič, 2023, original scientific article Keywords: Picea abies, spruce needles, extracellular particles, extracellular vesicles, small cellular particles, interferometric light microscopy, exosomes, cell-to-cell communication, drug delivery Published in DiRROS: 07.02.2024; Views: 359; Downloads: 199 Full text (2,49 MB) This document has many files! More... |
1919. A coupled domain–boundary type meshless method for phase-field modelling of dendritic solidification with the fluid flowTadej Dobravec, Boštjan Mavrič, Rizwan Zahoor, Božidar Šarler, 2023, original scientific article Abstract: Purpose - This study aims to simulate the dendritic growth in Stokes flow by iteratively coupling a domain and boundary type meshless method. Design/methodology/approach - A preconditioned phase-field model for dendritic solidification of a pure supercooled melt is solved by the strong-form space-time adaptive approach based on dynamic quadtree domain decomposition. The domain-type space discretisation relies on monomial augmented polyharmonic splines interpolation. The forward Euler scheme is used for time evolution. The boundary-type meshless method solves the Stokes flow around the dendrite based on the collocation of the moving and fixed flow boundaries with the regularised Stokes flow fundamental solution. Both approaches are iteratively coupled at the moving solid–liquid interface. The solution procedure ensures computationally efficient and accurate calculations. The novel approach is numerically implemented for a 2D case. Findings - The solution procedure reflects the advantages of both meshless methods. Domain one is not sensitive to the dendrite orientation and boundary one reduces the dimensionality of the flow field solution. The procedure results agree well with the reference results obtained by the classical numerical methods. Directions for selecting the appropriate free parameters which yield the highest accuracy and computational efficiency are presented. Originality/value - A combination of boundary- and domain-type meshless methods is used to simulate dendritic solidification with the influence of fluid flow efficiently. Keywords: dendritic solidification, Stokes flow, phase-field method, space-time adaptivity, meshless methods, RBF-FD, modified method of regularised sources Published in DiRROS: 07.02.2024; Views: 367; Downloads: 170 Full text (1,07 MB) This document has many files! More... |
1920. Oligomeric fragments distribution, structure and functionalities upon ruthenium-catalyzed technical lignin depolymerizationTina Ročnik, Erika Bartolomei, Anthony Dufour, Sébastien Leclerc, Philippe Arnoux, Blaž Likozar, Edita Jasiukaityte, Miha Grilc, Yann Le-Brech, 2024, original scientific article Published in DiRROS: 07.02.2024; Views: 300; Downloads: 163 Full text (4,79 MB) This document has many files! More... |