91. Sustainable biocarbon/tung oil coatings with hydrophobic and UV-shielding properties for outdoor wood substratesLaetitia Sarah Jennifer Marrot, Mariem Zouari, Matthew Schwarzkopf, David Brian DeVallance, 2023, original scientific article Abstract: With wood regaining substantial interest as a construction material due to sustainability concerns and aesthetics trends, efficient and safe protection methods are needed to prevent the discouloration and the loss of mechanical properties of this renewable and UV-sensitive material. In this study, sustainable coatings comprising 0 to 20 wt % biocarbon (BC) dispersed in tung oil were developed for wood protection. BC particles were added as ultraviolet (UV) absorbers and were produced by various carbonization routes. The BC powders were characterized in terms of particle size and surface functional groups by Fourier-Transform infrared, and the UV and visible absorbance of dispersed BC powders in water solutions were related to these characteristics.
Two wooden substrates (beech and oak) were coated with the developed coatings and the samples underwent six months of onsite weathering. While the total colour change of uncoated samples and tung oil-coated substrates without BC kept increasing over time and resulted in a clear alteration of the wood surface aesthetics, an increased BC content in the coatings led to enhanced colour stability, with alteration of the colour close to 2 for both wood species after six months of weathering for 10 and 20 wt% BC.
Coating with tung oil made the wooden substrates, initially hydrophilic, become hydrophobic, and the further introduction of biocarbon increased hydrophobicity. However, the increase in BC content was not correlated with an increase in water repellence, the highest water contact angle being observed for 5 % BC, and no further improvement in hydrophobicity was observed with higher BC content. The weathering negatively affected the water repellence of all the samples (i.e., reference samples and coated samples with various BC content). However, the introduction of 20 % BC best protected the decrease in water repellence induced by the onsite weathering. Keywords: biocarbon, biochar, coating, wood protection, hydrophobic coating, wettability Published in DiRROS: 30.05.2023; Views: 522; Downloads: 548
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92. Application of electrochemical methods for studying steel corrosion in alkali-activated materialsShishir Mundra, Gabriel Samson, Giulia Masi, Rebecca Achenbach, David M. Bastidas, Susan A. Bernal, Maria Chiara Bignozzi, Maria Criado, Martin Cyr, Nina Gartner, Stefanie von Greve‐Dierfeld, Andraž Legat, Nikoonasab Ali, John L. Provis, Michael Raupach, Gregor J. G. Gluth, 2023, original scientific article Abstract: Alkali‐activated materials (AAMs) are binders that can complement and partially substitute the current use of conventional cement. However, the present knowledge about how AAMs protect steel reinforcement in concrete elements is incomplete, and uncertainties exist regarding the application of electrochemical methods to investigate this issue. The present review by EFC WP11‐Task Force ‘Corrosion of steel in alkali‐activated materials’ demonstrates that important differences exist between AAMs and Portland cement, and between different classes of AAMs, which are mainly caused by differing pore solution compositions, and which affect the outcomes of electrochemical measurements. The high sulfide concentrations in blast furnace slag‐based AAMs lead to distinct anodic polarisation curves, unusually low open circuit potentials, and low polarisation resistances, which might be incorrectly interpreted as indicating active corrosion of steel reinforcement. No systematic study of the influence of the steel–concrete interface on the susceptibility of steel to corrosion in AAMs is available. Less common electrochemical methods present an opportunity for future progress in the field. Keywords: alkali-aktivated materials, alkali‐activated materials, anodic/cathodic polarisation, concrete, linear polarisation resistance, open circuit potential, reinforcement corrosion, resistivity Published in DiRROS: 29.05.2023; Views: 479; Downloads: 246
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93. Mode I fracture of beech-adhesive bondline at three different temperaturesJaka Gašper Pečnik, Andreja Pondelak, Michael David Burnard, Václav Sebera, 2022, original scientific article Abstract: Single edge-notched three-point bending tests (SEN-TPB) for mode I were utilized to experimentallyevaluate fracture properties of adhesive bondlines in European beech (Fagus SylvaticaL.). Thebondline was examined at two anatomical planes with TR and RT orientation and at control andtwo elevated temperatures (70°C and 140°C). Among epoxy (EPI), melamine-urea formaldehyde (MUF), and polyurethane (PUR) adhesives, the highest average critical energyGcwith 0.80 N/mmand fracture energyGfwith 1079.4 N/mm were obtained for EPI in the TR plane and understandard climate conditions (20°C/65% relative humidity), followed by MUF (Gc= 0.50 N/mm andGf= 620 N/mm) and PUR (Gc= 0.25 N/mm andGf= 290.9 N/mm), respectively. PUR was leasteffected by elevated temperature, and no significant differences forGcandGfbetween TR and RTbondline orientations were found for MUF and PUR treated at 20°C/65% relative humidity whilecomparisons between other factors varied significantly. Treatment of specimens at elevatedtemperatures resulted in reduced fracture performance regardless of wood grain orientation orthe adhesive system. Keywords: crack, fracture, grain orientation, temperature, European Beech, odprti dostop Published in DiRROS: 03.05.2023; Views: 672; Downloads: 514
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94. Multiscale femoral neck imaging and multimodal trabeculae quality characterization in an osteoporotic bone sampleEnrico Soldati, Flavy Roseren, Daphne Guenoun, Lucia Mancini, Emilio Catelli, Silvia Prati, Giorgia Sciutto, Jerome Vicente, Stefano Iotti, David Bendahan, Emil Malucelli, Martine Pithioux, 2022, original scientific article Abstract: Although multiple structural, mechanical, and molecular factors are definitely involved in osteoporosis, the assessment of subregional bone mineral density remains the most commonly used diagnostic index. In this study, we characterized bone quality in the femoral neck of one osteoporotic patients as compared to an age-matched control subject, and so used a multiscale and multimodal approach including X-ray computed microtomography at different spatial resolutions (pixel size: 51.0, 4.95 and 0.9 µm), microindentation and Fourier transform infrared spectroscopy. Our results showed abnormalities in the osteocytes lacunae volume (358.08 ± 165.00 for the osteoporotic sample vs. 287.10 ± 160.00 for the control), whereas a statistical difference was found neither for shape nor for density. The osteoporotic femoral head and great trochanter reported reduced elastic modulus (Es) and hardness (H) compared to the control reference (−48% (p < 0.0001) and −34% (p < 0.0001), respectively for Es and H in the femoral head and −29% (p < 0.01) and −22% (p < 0.05), respectively for Es and H in the great trochanter), whereas the corresponding values in the femoral neck were in the same range. The spectral analysis could distinguish neither subregional differences in the osteoporotic sample nor between the osteoporotic and healthy samples. Although, infrared spectroscopic measurements were comparable among subregions, and so regardless of the bone osteoporotic status, the trabecular mechanical properties were comparable only in the femoral neck. These results illustrate that bone remodeling in osteoporosis is a non-uniform process with different rates in different bone anatomical regions, hence showing the interest of a clear analysis of the bone microarchitecture in the case of patients’ osteoporotic evaluation Keywords: synchrotron X-ray microtomography, bone, trabecular struicture, osteons, osteoporosis, phase-contrast imaging, open access Published in DiRROS: 28.04.2023; Views: 512; Downloads: 267
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95. Soil contamination in nearby natural areas mirrors that in urban greenspaces worldwideYu-Rong Liu, Marcel G. A. van der Heijden, Judith Riedo, Carlos Sanz-Lazaro, David J. Eldridge, Felipe Bastida, Eduardo Moreno-Jiménez, Xin-Quan Zhou, Hang-Wei Hu, Ji-Zheng He, Tine Grebenc, Tina Unuk Nahberger, 2023, original scientific article Abstract: Soil contamination is one of the main threats to ecosystem health and sustainability. Yet little is known about the extent to which soil contaminants differ between urban greenspaces and natural ecosystems. Here we show that urban greenspaces and adjacent natural areas (i.e., natural/semi-natural ecosystems) shared similar levels of multiple soil contaminants (metal(loid)s, pesticides, microplastics, and antibiotic resistance genes) across the globe. We reveal that human influence explained many forms of soil contamination worldwide. Socio-economic factors were integral to explaining the occurrence of soil contaminants worldwide. We further show that increased levels of multiple soil contaminants were linked with changes in microbial traits including genes associated with environmental stress resistance, nutrient cycling, and pathogenesis. Taken together, our work demonstrates that human-driven soil contamination in nearby natural areas mirrors that in urban greenspaces globally, and highlights that soil contaminants have the potential to cause dire consequences for ecosystem sustainability and human wellbeing. Keywords: soil contamination, urban greenspaces Published in DiRROS: 28.03.2023; Views: 808; Downloads: 381
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96. Ascertaining the knowledge of the general public and stakeholders in the forestry sector to invasive alien species - a Pan-European studyFlavius Balacenoiu, Anže Japelj, Iris Bernardinelli, Bastien Castagneyrol, György Csóka, Milka Glavendekić, Gernot Hoch, Boris Hrašovec, Silvija Krajter Ostoić, Márton Paulin, David Williams, Johan Witters, Maarten De Groot, 2023, original scientific article Abstract: Against the background of the phenomenon of globalisation, which has increasingly intensified in recent decades, invasive alien species (IAS) have led to biological invasions that have resulted in multiple negative effects on economies, human health, and especially on the environment. In order to control invasive alien species, preventive actions are considered the most effective methods. In this context, society can actively participate in the process of early detection and preventing the spread of these organisms, but there is a need to raise public awareness. In order for this process to take place in the most efficient way, it is necessary to initially evaluate the knowledge of the general public to IAS. Through a questionnaire that was circulated in ten European countries and had over two thousand respondents, this study aimed to investigate the level of knowledge of some stakeholders in the forestry sector regarding IAS. The results showed that a vast majority of respondents who participated in the study had heard about IAS and provided a correct definition of these organisms. Most of the respondents in this study heard for the first time about IAS from school, the Internet, or journal articles. Data analysis also showed that stakeholders in the forestry sector (foresters, forest owners, and members of environmental NGOs) were more likely than the other respondents to be aware of the impact of IAS. The results of this study offer an insight to researchers and decision makers assessing the differences of opinion regarding invasive alien species, and the necessary steps that could be adopted in the process of raising awareness in society. Keywords: citizen science, online survey, biosecurity Published in DiRROS: 09.03.2023; Views: 857; Downloads: 350
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97. Teaching feints to handball beginners, preliminary resultsDavid Henigman, Katarina Ohnjec, 2021, other scientific articles Abstract: The aim of this preliminary research was the evaluation of a two-month program for improvement of the single forward feint to the left with passage to the right, and single forward feint to the right with passage to the left by “shifting” the opponent’s hand. Six-teen young male handball players aged 9.64 ± 0.87 years participated in this study. The program was implemented over two months, during which 18 training sessions (35%) were conducted for the improvement of feint skills, from 52 training sessions overall. An initial video recording was made at the beginning of the period, and a final one at the end. Videos were analyzed by three experts, using a grading list and detailed grad-ing criteria. The basic parameters of descriptive statistics were determined for both variables. The metric characteristics of the expert estimation contribution were ana-lyzed through measures of reliability (Cronbach’s α) and homogeneity (average item inter-correlation). The non-parametric (Wilcoxon t-test) method was used to analyze changes in the levels of feint performance at different times. The results indicate satis-factory reliability and homogeneity of the tests (α1=0.90; r1=0.80; α2 =0.86; r2=0.87). Through insight into the results, a significant difference was spotted between the initial and final states of both motor skills acquisitions (T1 = 114.5, p= 0.01; T2 =7.00; p= 0.01). The limiting factors of the study may be the sample size, as well as the absence of a control group and of a validated evaluation of the instrument Keywords: handball, handball players, teaching methods, motor skills, work program, single feint Published in DiRROS: 02.03.2023; Views: 523; Downloads: 230
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98. First report of Erysiphe corylacearum on Corylus avellana and C. colurna in SloveniaJanja Zajc, Mojca Rot, David Snoj, Metka Žerjav, Hans-Josef Schroers, Barbara Piškur, Nikica Ogris, Ana Brglez, 2023, other scientific articles Keywords: common hazel, Turkish hazel, powdery mildew Published in DiRROS: 28.02.2023; Views: 698; Downloads: 310
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