191. Experimental investigation on the effect of natural fire exposure on the post-fire behavior of reinforced concrete beams using electric radiant panelBalša Jovanović, Robby Caspeele, Edwin Reynders, Geert Lombaert, Florian Put, Andrea Lucherini, Ruben Van Coile, 2024, izvirni znanstveni članek Povzetek: In this study, the effects of natural fire exposure on the post-fire behavior of concrete beams are investigated. The study is based on laboratory tests where three reinforced concrete beams were subjected to fire exposure using an electric radiant panel. This panel enables a precise application of radiative heat exposure closely mimicking natural fire exposure in a safe manner. During the test, the deflections, deformations and temperature changes are measured for all three concrete beams. Additionally, finite element modeling (FEM) is applied to supplement these tests, demonstrating the performance of existing structural fire engineering calculation tools in evaluating the burnout performance of concrete beams. The results of the tests show that the electric radiant panel provide a novel approach for fire simulation which is effective in replicating natural fire conditions, by applying the heat flux as specified in the Eurocode Parametric Fire Curve in a highly controlled manner. The uniformity of the temperature field measured inside the beams and the consistent deformations observed during the heat exposure across all three tests underscores the accuracy of the fire simulation. Furthermore, post-fire assessments reveal that while the exposed beams suffered some reduction in load-bearing capacity, they retained a significant portion of their original strength that was consistent across all three beams. The numerical simulations conducted in this study demonstrate a high level of accuracy in predicting the behavior of the concrete beams during fire exposure. These simulations effectively mirrored the experimental results, validating that they are a valuable tool for assessing concrete structures' performance in fire scenarios.
Ključne besede: concrete beam, fire testing, numerical modeling, radiant panel
Objavljeno v DiRROS: 28.11.2024; Ogledov: 83; Prenosov: 31
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192. Exploratory study on the bending performance of thermo-hydro-mechanically densified Scots pine (Pinus sylvestris L.) at elevated temperaturesLei Han, Matthew Schwarzkopf, Jaka Gašper Pečnik, Wilson Ulises Rojas Alva, Andrea Lucherini, Andreja Kutnar, Dick Sandberg, 2024, drugi znanstveni članki Povzetek: Thermo-hydro-mechanical (THM) densification is a well-known wood modification procedure for improving the mechanical properties of low-density wood species, but its performance at elevated temperatures is not well understood. The objective of this study was to determine the bending behaviour of densified Scots pine at elevated temperatures. A total of 48 specimens (200 mm (longitudinonal) × 20 mm (radial) × 20 mm (tangential)) were tested to investigate the bending performance under constant temperatures at 25, 50, 125 and 175°C, respectively. It was found that the modulus of rupture (MOR) and modulus of elasticity (MOE) of both un-densified and densified pine decreased with increasing temperature. However, the densified wood exhibited more brittle shear failure but retained higher MOR and MOE than the untreated specimens treated at the same temperature level. In general, the results demonstrate that densification can be a potentially effective method to retain the mechanical properties of wood at elevated temperatures, thereby having a potential maintain the load-bearing capacity during and after fire.
Ključne besede: densification, wood, fire safety
Objavljeno v DiRROS: 28.11.2024; Ogledov: 81; Prenosov: 52
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193. Smernica o požarni varnosti fotonapetostnih sistemov na ravnih strehahGrunde Jomaas, Aleš Jug, Nik Rus, 2024, slovar, enciklopedija, leksikon, priročnik, atlas, zemljevid Ključne besede: fotonapetostni sistemi, PV, ravne strehe, zgradbe, požarna varnost, požarno tveganje
Objavljeno v DiRROS: 27.11.2024; Ogledov: 334; Prenosov: 1175
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194. Predlog tehničkog rešenja : sorta Plovidna - nova indikator biljka za detekciju fitoplazmi vinove lozeSlobodan Kuzmanović, Mira Starović, Danijela Ristić, Ana Vučurović, Nemanja Kuzmanović, Nenad Trkulja, Goran Aleksić, 2022, elaborat, predštudija, študija Objavljeno v DiRROS: 27.11.2024; Ogledov: 71; Prenosov: 18
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196. Diversity and pathogenicity of Botryosphaeriaceae and Phytophthora species involved in emerging diseases of Fagus sylvatica in Italy and SloveniaCarlo Bregant, Massimiliano Marcolongo, Lucio Montecchio, Nikica Ogris, Barbara Piškur, Benedetto Teodoro Linaldeddu, 2024, izvirni znanstveni članek Povzetek: Extensive sunken and bleeding cankers, shoot blight, and root rot symptoms on European beech (Fagus sylvatica L.) trees have recently been observed in several forest ecosystems in Italy and Slovenia. Since there is little information about the aetiology of these diseases and given the high economic and ecological relevance of these formations, a study was conducted from summer to autumn 2023 in ten sites to define the occurrence, distribution and impact of the main pathogens involved. A total of 116 symptomatic samples were collected and processed. Based on colony appearance, morphological features and DNA sequence data, six species belonging to the genera Botryosphaeria, Dothiorella, Diplodia, Neofusicoccum (fungi) and Phytophthora (oomycetes) were isolated and identified. Pathogenicity tests performed on potted European beech seedlings satisfied Koch postulates and highlighted that Diplodia corticola, Neofusicoccum parvum and Phytophthora plurivora are the main agents involved in the extensive decline affecting European beech ecosystems in Italy and Slovenia.
Ključne besede: Diplodia corticola, beech decline, invasive species, emerging diseases, co-infections
Objavljeno v DiRROS: 27.11.2024; Ogledov: 128; Prenosov: 750
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197. Bulk proton conduction in films from a truncated reflectin variantPreeta Pratakshya, Albert L. Kwansa, Matic Kovačič, Nikhil Kaimal, Arsenii Panteleev, Atrouli Chatterjee, Nadia E. Tolouei, Rylan Kautz, Kyle L. Naughton, Janez Plavec, 2024, izvirni znanstveni članek Objavljeno v DiRROS: 27.11.2024; Ogledov: 88; Prenosov: 510
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198. Price volatility and GHG emissions analysis on smaller cattle herds typical for the pre-Alpine region, the example of SloveniaJure Brečko, Črtomir Rozman, Jaka Žgajnar, 2024, izvirni znanstveni članek Ključne besede: agricultural input, output prices, price volatility, meat industry, climate change, GMG emissions, smale cattle herds, Slovenia, environmental regulations, animal welfare
Objavljeno v DiRROS: 27.11.2024; Ogledov: 106; Prenosov: 38
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