31. Manual for use of Al-containing residues in low-carbon mineral bindersSabina Dolenec, Katja Malovrh Rebec, Anja Lešek, Katarina Šter, Lea Žibret, Gorazd Žibret, Klemen Teran, Emil Pučko, Ildikó Merta, Bojan Poletanovic, Elena Yaneva, Peter Kesserű, Ildikó Kovács, Bence Kószó, Alexandra Németh, Richard Laucournet, Mustafa Hadžalić, Emilija Fidanchevski, Biljana Angjusheva, Vojo Jovanov, Miloš Nenadović, Snežana B. Nenadović, Ivana Vukanac, Liljana Kraljević, Mojca Loncnar, Andrej Ipavec, 2020, dictionary, encyclopaedia, lexicon, manual, atlas, map Abstract: Današnje družbe si ni več mogoče predstavljati brez sodobne infrastrukture, ki temelji na uporabi različnih materialov ter zahteva veliko porabo energije. Vzporedno s proizvodnjo materialov, nastajajo ogromne količine različnih industrijskih in rudarskih ostankov (odpadki/stranski proizvodi), ki jih trenutno ne izkoriščamo, sama odlagališča pa so premalo raziskana. Cilj Evropske unije (EU) je povečati učinkovito rabo virov in ponudbo sekundarnih surovin z recikliranjem, popisom odpadkov iz rudarskih in drugih industrijskih dejavnosti ter njihova ponovna uporaba. Veliko industrijskih in rudarskih odpadkov je obogatenih z aluminijem (Al), zato lahko nadomeščajo naravne vire Al v mineralnih veznih, vendar njihova uporaba zahteva obsežno poznavanje njihovih kemijskih, mineraloških, radioloških in fizikalnih lastnosti. Priročnik, ki so ga pripravili partnerji projekta RIS-ALiCE obravnava zakonodajne vidike, ki urejajo uporabo sekundarnih surovin v gradbenih proizvodih, opis najpogostejših industrijskih in rudarskih ostankov, ki vsebujejo Al (nahajališča boksitov, rdeče blato, jeklarske žlindre, pepeli iz različnih industrij, itd.), potencial njihove ponovne uporabe in njihov ekonomski vidik, potencialne zahteve/ovire za uporabo sekundarnih surovin v cementni industriji in opis belitno-sulfoaluminatnih cementov, ki so obetavna rešitev za izvajanje krožnega gospodarstva z uporabo velikih količin odloženih industrijskih in rudarskih odpadkov, bogatih z Al. Keywords: gradbeni proizvodi, ponovna uporaba, ekonomski vidik, industrija cementa, krožno gospodarstvo, industrijski odpadki, zakonodaja, elektronske knjige Published in DiRROS: 22.01.2024; Views: 264; Downloads: 105 Full text (4,51 MB) This document has many files! More... |
32. Corrosion monitoring of steel structure coating degradationBojan Zajec, Mirjam Bajt Leban, Tadeja Kosec, Viljem Kuhar, Andraž Legat, Stanislav Lenart, Karmen Fifer Bizjak, Gavin Kenneth, 2018, original scientific article Abstract: An important aspect regarding the sustainability of steel structures is to ensure the structure is protected from corrosion. A number of surface coatings are availablethat play an important role in protecting these structures. An important part of the management of these structures is reliable and regular inspection along with methods forearly detection of corrosion processes. In this paper, a development and application of sensors for monitoring the steel coating degradation and corrosion damage to steelsubstrate are presented. An encapsulated corrosion kit with integrated EIS sensors and ER probes was developed. To test its efficiency, steel probes were coated withselected coatings in the laboratory and their performance was assessed under various aggressive atmospheres, including; salt, industrial and humid atmosphere. Keywords: coatings, corrosion, electrochemical impedance spectroscopy, electrical resistance probes, railways, steel structures Published in DiRROS: 13.12.2023; Views: 222; Downloads: 109 Full text (2,45 MB) This document has many files! More... |
33. Parametarska studija kolničke konstrukcije ojačane geoćelijamaSamo Peter Medved, Bojan Žlender, Stanislav Lenart, 2018, original scientific article Abstract: U radu je prikazano parametarsko ispitivanje kolničke konstrukcije ojačane geoćelijama. Analiza temeljena na metodi konačnih elemenata uključuje model neojačane kolničke konstrukcije te model kolničke konstrukcije ojačane geoćelijama, pri čemu se analiziraju razni položaji, debljine i čvrstoća geoćelija. U okviru modela određen je i očekivani vijek trajanja kolničke konstrukcije. Rezultati parametarskog proučavanja u skladu su s rezultatima analitičkih rješenja, laboratorijskih i terenskih ispitivanja. Dobiveni rezultati upućuju na bitno poboljšanje nosivosti, smanjenje debljine asfaltnih slojeva i povećanje trajnosti kolničke konstrukcije kada je ona ojačana geoćelijama. Published in DiRROS: 12.12.2023; Views: 224; Downloads: 155 Full text (444,79 KB) This document has many files! More... |
34. Klinične in histološke značilnosti ploščatoceličnega karcinoma kožePeter H. Soyer, Borut Žgavec, Bojan Popovič, 1999, review article Abstract: Ploščatocelični karcinom je druga najpogostejša maligna novotvorba kože. Najpomembnejši etiološki dejavnik je kronična izpostavljenost UV žarkom. Klinična slika je zelo raznovrstna, kar povzroča težave pri ločevanju teh tumorjev od drugih bolezni, predvsem pa bazalioma. Dokončno diagnozo postavimos histološko, v dvomljivih primerih pa uporabimo še imunohistokemičnopreiskavo. Published in DiRROS: 28.11.2023; Views: 329; Downloads: 70 Full text (276,27 KB) |
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36. Elucidating nucleation stages of transgranular stress corrosion cracking in austenitic stainless steel by in situ electrochemical and optical methodsSarmiento Klapper Helmuth, Bojan Zajec, Andreas Heyn, Andraž Legat, 2019, original scientific article Abstract: The pitting and environmentally assisted cracking resistance of austenitic stainless steels (SS) is challenged in several industrial applications particularly those involving hot chloride-concentrated streams. Directional drilling used in the oil and gas exploration is one of these applications. Indeed, high strength CrMn-SS commonly used in drilling technology have a high tendency to fail by stress corrosion cracking (SCC) preceded by localized corrosion once subjected to highly chloride-concentrated drilling fluids at elevated temperatures. A comprehensive understanding regarding the mechanisms governing the transition from pitting into SCCis not currently available, though. Therefore, mechanistic aspects such as the effect of loading conditions on pit nucleation and repassivation as well as the synergistic effect between pit stabilization and the nucleation of a stress corrosion crack are of great practical significance. To investigate this an electrochemical-, optical- and mechanical- monitored SCC test was conducted on a CrMn-SS in an alkaline brine at elevated temperature. The transition from metastable to stable pitting and subsequently to SCC in this system was documented in-situ for the first time. Results supported H.S. Isaacs postulates regarding the interpretation of electrochemical signals and demonstrated that loading conditions affect pit nucleation and repassivation leading to a higher susceptibility of the material to pitting, which preceded SCC. Keywords: pitting corrosion, stress corrosion cracking, monitoring, elektrochemical noise, austenitic stainless steel Published in DiRROS: 23.11.2023; Views: 277; Downloads: 204 Full text (2,28 MB) This document has many files! More... |
37. Activation and repassivation of stainless steels in artificial brines as a function of pHEmir Mujanović, Bojan Zajec, Tadeja Kosec, Andraž Legat, Stefan Hönig, Gerald Zehethofer, Gregor Mori, 2019, original scientific article Abstract: When planning oil wells with stainless steel components, two possible reasons for depassivation have to be considered-chemical depassivation caused by acidizing jobs and mechanical depassivation caused by various tools and hard particles. The study explores conditions causing chemical activation of investigated steels and circumstances under which repassivation occurs after activation. The main focus of the study is to determine, how quickly various steels can repassivate under different conditions and to find pH values where repassivation will occur after depassivation. The investigated steels were ferritic (martensitic or bainitic) in the cases of 13Cr, 13Cr6Ni2Mo, and 17Cr4Ni2Mo, austenitic in the case of 17Cr12Ni2Mo, and duplex (austenitic and ferritic) in the case of 22Cr5Ni3Mo. Potentiodynamic experiments were employed to obtain electrochemical properties of investigated steels, followed by immersion tests to find ultimate conditions, where the steels still retain their passivity. After obtaining this information, scratch tests were performed to study the repassivation kinetics. It was found that repassivation times are similar for nearly all investigated steels independent of their chemical composition and microstructure. Keywords: stainless steels, activation, repassivation Published in DiRROS: 21.11.2023; Views: 288; Downloads: 132 Full text (4,47 MB) This document has many files! More... |
38. 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: 473; Downloads: 79 Full text (1,66 MB) This document has many files! More... |
39. Hierarchical learning of robotic contact policiesMihael Simonič, Aleš Ude, Bojan Nemec, 2023, original scientific article Abstract: The paper addresses the issue of learning tasks where a robot maintains permanent contact with the environment. We propose a new methodology based on a hierarchical learning scheme coupled with task representation through directed graphs. These graphs are constituted of nodes and branches that correspond to the states and robotic actions, respectively. The upper level of the hierarchy essentially operates as a decision-making algorithm. It leverages reinforcement learning (RL) techniques to facilitate optimal decision-making. The actions are generated by a constraint-space following (CSF) controller that autonomously identifies feasible directions for motion. The controller generates robot motion by adjusting its stiffness in the direction defined by the Frenet–Serret frame, which is aligned with the robot path. The proposed framework was experimentally verified through a series of challenging robotic tasks such as maze learning, door opening, learning to shift the manual car gear, and learning car license plate light assembly by disassembly. Keywords: autonomous robot learning, learning, experience, compliance and impedance contro Published in DiRROS: 21.09.2023; Views: 445; Downloads: 217 Full text (1,73 MB) This document has many files! More... |
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