51. Analysis of loading profile effect on testing machine calibration resultsMiha Hiti, 2021, original scientific article Abstract: The paper presents an evaluation of the loading profile effect on the testing machine calibration. First, a 20 kN force transducer was calibrated in a force calibration machine. This transducer was then used for a number of calibration runs in a 600 kN material testing machine where the time step interval of the same loading profile was varied from 120 s to 0 s. Results show good agreement for most of the range but highlight an increasing error due to synchronization and filtering issues in measured signals when approaching very short step intervals and continuous loading.
Keywords: force calibration, loading profile, measurement uncertainty, continuous loading
Published in DiRROS: 20.12.2023; Views: 282; Downloads: 133
 Full text (4,42 MB)
This document has many files! More... |
52. Compensation of synchronization error effect in testing machine calibrationMiha Hiti, 2021, original scientific article Abstract: The paper presents an evaluation of synchronization issues when performing material testing machine calibration using continuous loading. A procedure for the compensation of a rangewide error in calibrated force values is proposed based on a correction factor determined from static and transient errors difference at a chosen force step. The procedure was applied for a calibration of a testing machine with a 20 kN force transducer and 200 N/s to 2000 N/s loading rates. The results show good performance of the compensation technique, reducing calibration errors to below 1% in non-synchronized signals even under unknown filter and delay setting.
Keywords: force calibration, loading profile, measurement uncertainty, continuous loading
Published in DiRROS: 20.12.2023; Views: 251; Downloads: 113
Full text (5,97 MB)
This document has many files! More... |
53. Selective demethylation reactions of biomass-derived aromatic ether polymers for bio-based lignin chemicalsFlorian Maximilian Harth, Brigita Hočevar, Tina Ročnik, Edita Jasiukaityte, Jana Blüm, Michael Fiedel, Blaž Likozar, Miha Grilc, 2023, review article Published in DiRROS: 18.12.2023; Views: 321; Downloads: 112
Full text (2,29 MB)
This document has many files! More... |
54. Potresni odziv večetažnih strižnih zidanih sten in učinek utrjevanja s kompozitnimi oblogamiPetra Triller, Miha Tomaževič, Matija Gams, 2018, original scientific article Abstract: večetažnih sten, sezidanih iz modularnih zidakov, s poudarkom na opazovanju mehanizmov odziva in porušitve, ki se razvijejo v večetažnih stenah z odprtinami. Druga tema je osredotočena na raziskave utrjevanja takšnega zidovja z malto, armirano z mrežicami iz steklenih vlaken. Za raziskave smo na Zavodu za gradbeništvo Slovenije zgradili in preiskali posamezne zidove in večji trietažni preizkušanec v naravni velikosti. V cikličnem strigu pri konstantnem tlaku smo preizkusili več referenčnih in utrjenih zidov ter trietažni model dimenzij 4 x 4 m v tlorisu in višine 6,7 m. Trietažni model smo najprej obremenili do večjih, a popravljivih poškodb. Zatem smo poškodovani preizkušanec utrdili s kompozitnimi oblogami iz malte, armirane s steklenimi vlakni (GFRP), ter ga ponovno preiskali, tokrat skoraj do porušitve. V obeh primerih je bil odziv modela na vodoravno obtežbo s t. i. etažnim mehanizmom, pri katerem se večina poškodb skoncentrira v zidovih najšibkejše etaže. V zidovih smo opazili tipične strižne poškodbe z diagonalnimi razpokami. Potresno obnašanje posameznih zidov je bilo zelo podobno odzivu zidnih slopov večetažnega preizkušanca. Rezultati kažejo, da je mogoče z ustreznim načinom utrjevanja zidov doseči občutno izboljšanje potresnega obnašanja.
Keywords: nearmirano zidovje, laboratorijske preiskave, ciklične strižne preiskave, GFRP-kompoziti, utrjevanje
Published in DiRROS: 13.12.2023; Views: 270; Downloads: 104
Full text (7,47 MB)
This document has many files! More... |
55. Odpornost lesa izbranih lesnih vrst na prostemMiha Humar, Boštjan Lesar, Davor Kržišnik, 2023, original scientific article Abstract: Velika večina drevesnih vrst iz slovenskih gozdov nima odpornega lesa, zato na prostem (pre)hitro propade. Kadar les uporabljamo v gospodarske namene, želimo te procese čim bolj upočasniti. V okviru raziskave smo v ta namen les izbranih domačih drevesnih vrst (navadne smreke (Picea abies), les smrekovih lubadark, bele jelke (Abies alba), beljave in jedrovine rdečega bora (Pinus sylvestris), jedrovine evropskega macesna (Larix decidua), navadne bukve (Fagus sylvatica), belega gabra (Carpinus betulus) in jedrovine robinije (Robinia pseudoaccacia)) impregnirali z baker-etanolaminskim biocidnim proizvodom oziroma jih termično modificirali. Vzorce smo leta 2007 izpostavili na terensko polje Oddelka za lesarstvo v Ljubljani, kjer smo vsako leto ocenjevali razkrojenost. Najhitreje so propadli vzorci gabra in bukve. Prvi razkroj na smrekovini se je pojavil po dveh letih. Les lubadark je začel trohneti leto pred referenčno smrekovino, macesnovina in jedrovina bora pa leto kasneje. Najbolje se je izkazal les robinije. Z impregnacijo smo uspešno zaščitili les iglavcev, pri bukovini in gabrovini smo bili manj uspešni. Termična modifikacija se je izkazala za uspešen postopek zaščite za vse preizkušane lesne vrste.
Keywords: les, naravna odpornost, razkroj, modifikacija lesa, impregnacija lesa
Published in DiRROS: 12.12.2023; Views: 375; Downloads: 85
Full text (270,74 KB) |
56. Atmosphere - vegetation - soil interactions in a climate change context; impact of changing conditions on engineered transport infrastructure slopes in EuropeAnh Minh Tang, P. N. Hughes, T. A. Dijkstra, Amin Askarinejad, Mihael Brenčič, Yu Jun Cui, J. J. Diez, T. Firgi, Beata Gajewska, F. Gentile, G. Grossi, C. Jommi, F. Kehagia, E. Koda, H. W. ter Maat, Stanislav Lenart, S. Lourenco, M. Oliveira, P. Osinski, Sarah Springman, Ross Stirling, D. G. Toll, Ursula J. Van Beek, 2018, original scientific article Abstract: In assessing the impact of climate change on infrastructure, it is essential to consider the interactions between the atmosphere, vegetation and the near-surface soil. This paper presents an overview of these processes, focusing on recent advances from the literature and those made by members of COST Action TU1202 - Impacts of climate change on engineered slopes for infrastructure. Climate- and vegetation-driven processes (suction generation, erosion, desiccation cracking, freeze-thaw effects) are expected to change in incidence and severity, which will affect the stability of new and existing infrastructure slopes. This paper identifies the climate- and vegetation-driven processes that are of greatest concern, the suite of known unknowns that require further research, and lists key aspect that should be considered for the design of engineered transport infrastructure slopes in the context of climate change.
Published in DiRROS: 12.12.2023; Views: 231; Downloads: 114
Full text (2,29 MB)
This document has many files! More... |
57. Selective glucose oxidation to glucaric acid using bimetallic catalysts : lattice expansion or electronic structure effect?Žan Lavrič, Janvit Teržan, Ana Kroflič, Janez Zavašnik, Joanna E. Olszówka, Štefan Vajda, Matej Huš, Miha Grilc, Blaž Likozar, 2024, original scientific article Abstract: Our study presents a comprehensive approach for the selective oxidation of glucose to glucaric acid (GA) by heterogeneous catalysis. We have synthesized and characterized Au/ZrO2, AuCu/ZrO2 and AuPt/ZrO2 catalysts using X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and oxygen pulse chemisorption (OPS) techniques. Combining experimental observations with in-depth density functional theory (DFT) studies, we found that bimetallic catalysts form alloys, which exhibit different characteristics than monometallic counterparts for the given reaction. We performed batch reactions, varying temperature and oxygen pressure, and used the data to construct a predictive microkinetic model. As it turned out, AuPt/ZrO2 showed the highest selectivity, yielding 32 % of GA at 100 °C and 30 barg O2. Our results provide valuable insights for the developing of efficient catalysts and point out the bottlenecks for the oxidation of glucose to GA.
Keywords: glucaric acid, glucose oxidation, catalyst characterization, density functional theory, microkinetic modelling
Published in DiRROS: 06.12.2023; Views: 291; Downloads: 156
Full text (2,73 MB)
This document has many files! More... |
58. Presejanje za odkrivanje raka dojkKristijana Hertl, Miljeva Rener, Tomaž Vargazon, Maksimiljan Kadivec, Maja Podkrajšek, Maja Marolt-Mušič, Simona Jereb, Miha Čavlek, 2004, published scientific conference contribution Abstract: Izhodišča. Rak dojk (RD) je zaradi visoke incidence v razvitem svetu in v Sloveniji velik zdravstveni in ekonomski problem. Redno mamografsko pregledovanje asimptomatskih žensk (presejanje oz. screening), starih 50-69 let dolgoročno zmanjša umrljivost za RD, ker odkrije raka v zgodnejši fazi. V Sloveniji presejanje ni organizirano tako kot v nekaterih evropskih državah, ampak je oportunistično, ko ženske preventivno prihajajo v centre za bolezni dojk (CBD) na pregled po priporočilu zdravnika ali po lastni želji. Za kakovost delovanja centri nimajo enotnih državnih smernic in nad njihovim delovanjem ni nadzora. Zaključki. Uspešnost presejanja je odvisna od izbora skupine primerne starosti, udeležbe, intervala med posameznimi krogi presejanja, števila projekcij, dvojnega odčitovanja, kontrole kakovosti ter rednega beleženja in analize doseženih rezultatov. Glavne pomanjkljivosti presejanja so napačno pozitivni in napačno negativni izvidi, izpostavljenost ionizirajočem sevanju ter prediagnosticiranost.
Published in DiRROS: 01.12.2023; Views: 260; Downloads: 79
Full text (639,35 KB) |
59. Experimental investigation of the axial strength of glued-in rods in cross laminated timberBoris Azinović, Erik Serrano, Miha Kramar, Tomaž Pazlar, 2018, original scientific article Abstract: This paper presents results from an experimental assessment of glued-in rods in cross laminated timber (CLT). For the purposes of the study more than 60 pull-pull tests were performed, where the specimens varied in terms of bonded-in length (from 80 to 400 mm), rod diameter (16-24 mm) and rod-to-grain angle (parallel and perpendicular). Several different failure modes that are not common for other applications of glued-in rods (e.g., a failure between CLT layers) were obtained for the analysed CLT specimens. It was found that these failure mechanisms can substantially influence the obtained ultimate tension loads. At the end, the experimental results were compared with empirical and semi-empirical equations for estimating the pull-out strength of glued-in rods in structural timber and glulam. The comparison showed that most of the existing equations overestimate the ultimate tension loads for specimens with the rod parallel to the grain and underestimate the ultimate tension load for specimens with the rod perpendicular to the grain. The results vary because the possible CLT failure modes were not included in previous studies. Further studies are proposed to improve the equations for glued-in rods in CLT.
Keywords: glued-in rods, cross laminated timber (CLT), pull-pull experiment, glued-in length, rod-to-grain angle, failure mechanisms in CLT
Published in DiRROS: 29.11.2023; Views: 283; Downloads: 208
Full text (4,13 MB)
This document has many files! More... |
60. Obsevanje ginekoloških tumorjevBarbara Šegedin, Helena Barbara Zobec Logar, Manja Šešek, Ana Perpar, Blaž Grošelj, Miha Oražem, 2023, professional monograph Keywords: teleterapija, brahiterapija, prehrana, kemoterapija, stranski učinki
Published in DiRROS: 22.11.2023; Views: 433; Downloads: 121
Full text (1,18 MB) |
