1901. Why are the Early Gothic murals in St. Jacob’s Church in Ormož, Slovenia, almost entirely black?Anabelle Križnar, Katja Kavkler, Sabina Dolenec, 2024, original scientific article Abstract: In St. Jacob’s parish church in Ormož, Slovenia, mural paintings from around 1350–1370 are partially conserved in the northeastern corner of the main nave. They are almost completely black, indicating a large-scale pigment degradation. They were studied as a part of a larger research project aiming to identify materials applied and their possible degradation. First, they were studied in situ, and next, extracted samples of plaster, pigments, and colour layers were analysed by optical microscopy, Raman spectroscopy, FTIR spectroscopy, SEM-EDS, and XRD. Haematite, green earth, malachite, azurite, and tenorite were identified, showing that azurite and perhaps also malachite degraded to black tenorite, probably due to their fine grinding and their application directly on the fresh plaster. The plaster is made with small and large amounts of aggregate with mostly quartz with some impurities, which makes it fragile. The original appearance of these murals was of bright blue and green colours.
Keywords: mural painting, medieval painting, Gothic art, St. Jacob's Church, Ormož, Slovenia, pigments, chemical structure, colour degradation, optical microscopy, Raman microspectroscopy, FTIR, XRD
Published in DiRROS: 17.04.2024; Views: 398; Downloads: 352
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1902. Foot posture index and hip joint rotation mobility in handball and soccer playersTjaž Brezovar, Matej Drobnič, Alan Kacin, 2023, original scientific article Abstract: Purpose: To assess the foot posture and hip joint mobility of elite handball and soccer players and to investigate possible correlations between these measurements. Methods: We compared the differences in means of Foot Posture Index (FPI), pas-sive hip internal (IR), and external (ER) rotation range of motion (ROM) between three groups of male subjects (17 handball players, 17 soccer players, and 16 non-athletes). The Kruskal-Walli’s test and post-hoc pairwise comparison with the Mann-Whitney U test were used to determine the differences between the group means, and associations between variables were analyzed with Spearman’s correlation coefficient. Results: No significant differences in the mean FPI were found between the soccer players (1.3 ± 2.9), handball players (0.7 ± 2.1), and the control group (1.7 ± 2.5) (p > 0.05). Similarly, no significant difference was found between the groups in the hip ER ROM. In contrast, a significantly lower (p < 0.05) hip IR ROM was observed in the soccer players (30.6° ± 5.3°) compared to the handball players (41.0° ± 8.1°) and the control group (41.1° ± 6.4°). A weak positive correlation was only observed between the FPI and hip IR ROM in the soccer players (ρ: 0.36, p = 0.035). Conclusions: Handball and soccer players show a tendency toward less pronated feet compared to non-athletes, but the differences are not significant and the mean FPI values are still within the range of normal foot posture. The range of hip IR seems to be reduced in soccer players and weakly, but significantly and positively associated with the FPI value, which needs to be further investigated in future studies.
Keywords: foot shape, hip mobility, soccer players, handball players
Published in DiRROS: 17.04.2024; Views: 396; Downloads: 288
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1903. Model uncertainty in a parametric fire curve approach : a stochastic correction factor for the compartment fire load densityFlorian Put, Andrea Lucherini, Bart Merci, Ruben Van Coile, 2024, original scientific article Abstract: A commonly used approach to represent the thermal load in a compartment fire is the Eurocode Parametric Fire Curve (EPFC), which specifies gas temperatures (or rather adiabatic surface temperatures). Recognizing the significant deviations between real fires and the EPFC framework, the concept of model uncertainty is explored. This study does not aim to assess or improve the EPFC, but introduces a model uncertainty, allowing for reliability-based structural fire engineering (SFE). It presents a stochastic correction factor for the fire load density, based on the maximum temperature in steel sections. The focus is on the fire load density, but in general other parameters can be jointly taken into account as well. This correction factor considers protected and un- protected sections, incorporating variations in section factor and protection thickness. The findings reveal that the fire load density within the EPFC framework can be modified to better represent the severity of fire ex- periments. This approach ensures physical consistency of the obtained compartment gas temperatures, as opposed to alternative approaches for addressing the EPFC model uncertainty. While promising results are evident in this proof of concept, exploration for other types of structural elements and evaluation for structural systems is necessary before integration into design practices.
Keywords: structural fire engineering, compartment fires, fire load density, steel structures, reliability, probability of failure
Published in DiRROS: 17.04.2024; Views: 424; Downloads: 85
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1904. Modelling intumescent coatings for the fire protection of structural systems : a reviewAndrea Lucherini, Donatella de Silva, 2024, review article Abstract: Purpose
Intumescent coatings are nowadays a dominant passive system used to protect structural materials in case of fire. Due to their reactive swelling behaviour, intumescent coatings are particularly complex materials to be modelled and predicted, which can be extremely useful especially for performance-based fire safety designs. In addition, many parameters influence their performance, and this challenges the definition and quantification of their material properties. Several approaches and models of various complexities are proposed in the literature, and they are reviewed and analysed in a critical literature review.
Design/methodology/approach
Analytical, finite-difference and finite-element methods for modelling intumescent coatings are compared, followed by the definition and quantification of the main physical, thermal, and optical properties of intumescent coatings: swelled thickness, thermal conductivity and resistance, density, specific heat capacity, and emissivity/absorptivity.
Findings
The study highlights the scarce consideration of key influencing factors on the material properties, and the tendency to simplify the problem into effective thermo-physical properties, such as effective thermal conductivity. As a conclusion, the literature review underlines the lack of homogenisation of modelling approaches and material properties, as well as the need for a universal modelling method that can generally simulate the performance of intumescent coatings, combine the large amount of published experimental data, and reliably produce fire-safe performance-based designs.
Research limitations/implications
Due to their limited applicability, high complexity and little comparability, the presented literature review does not focus on analysing and comparing different multi-component models, constituted of many model-specific input parameters. On the contrary, the presented literature review compares various approaches, models and thermo-physical properties which primarily focusses on solving the heat transfer problem through swelling intumescent systems.
Originality/value
The presented literature review analyses and discusses the various modelling approaches to describe and predict the behaviour of swelling intumescent coatings as fire protection for structural materials. Due to the vast variety of available commercial products and potential testing conditions, these data are rarely compared and combined to achieve an overall understanding on the response of intumescent coatings as fire protection measure. The study highlights the lack of information and homogenisation of various modelling approaches, and it underlines the research needs about several aspects related to the intumescent coating behaviour modelling, also providing some useful suggestions for future studies.
Keywords: intumescent coatings, fire protection, modelling, structural fire engineering, fire safety, performance-based design
Published in DiRROS: 17.04.2024; Views: 462; Downloads: 248
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1905. Položaj priseljencev na področju zdravja in zdravstvenega varstva v SlovenijiRomana Bešter, Mojca Medvešek, Janez Pirc, 2020, independent scientific component part or a chapter in a monograph Keywords: integracija priseljencev, priseljenci, zdravje, zdravstveno varstvo, Slovenija, integracijska politika
Published in DiRROS: 16.04.2024; Views: 512; Downloads: 179
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1907. Razvoj integracijskih programov za priseljence v SlovenijiMojca Medvešek, Romana Bešter, Janez Pirc, 2020, independent scientific component part or a chapter in a monograph Keywords: integracija, integracijska politika, integracijski programi, državljani držav nečlanic Evropske unije, začetna integracija priseljencev, slovenski jezik, Slovenija
Published in DiRROS: 16.04.2024; Views: 502; Downloads: 165
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