1. Influence of test methodology on the characterization of the parallel-to-grain timber embedment strength and foundation modulus of dowelsCaroline D. Aquino, Rodrigues Leonardo G., Michael Schweigler, Meta Kržan, Zheng Li, Jorge M. Branco, 2024, izvirni znanstveni članek Povzetek: A reliable determination of the embedment strength and foundation modulus of timber elements is critical for the design and safety assessment of joints in timber structures. However, the existence of various test configurations for characterising the embedding properties of large diameter steel fasteners in timber elements poses challenges in directly comparing and utilising available test data. This paper aims to provide an insight into the influence of embedment property test methods, comparing experimental results from different test setups within the guidelines of the EN 383 and ASTM D 5764-97a standards for European softwood species, Scots pine wood (Pinus sylvestris) and Norway spruce (Picea abies). In addition to the test guidelines, the thickness of the specimen and the application of the load was evaluated within the protocols. A comprehensive statistical analysis was performed to identify statistically significant differences between the groups evaluated. The results of the analysis revealed disagreement between the standards in the evaluation of the strength of the embedding, highlighting the potential bias inserted by the experimental setup and protocol. Furthermore, it was proven that the thickness of the specimens influences both the embedding strength and the foundation modulus of the wood species tested. Finally, no distinctions were observed between tensile and compressive loading within the guidelines of the EN 383 standard.
Ključne besede: embedment strength, foundation modulus, dowel-type connections, test methods
Objavljeno v DiRROS: 15.04.2024; Ogledov: 43; Prenosov: 25
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2. 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, izvirni znanstveni članek Povzetek: 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.
Ključne besede: soil contamination, urban greenspaces
Objavljeno v DiRROS: 28.03.2023; Ogledov: 586; Prenosov: 233
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3. Effect of temperature on MgO activity in the CaO-SiO[sub]2-MgO-Al[sub]2O[sub]3 system measured by molten tinYongchun Guo, Fengman Shen, Haiyan Zheng, Shuo Wang, Xin Jiang, Qiangjian Gao, 2022, izvirni znanstveni članek Ključne besede: blast furnace, slag system, activity of MgO, reference-slag, method, enthalpy, solution
Objavljeno v DiRROS: 22.06.2022; Ogledov: 449; Prenosov: 122
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4. Global homogenization of the structure and function in the soil microbiome of urban greenspacesManuel Delgado-Baquerizo, David J. Eldridge, Yu-Rong Liu, Blessing Sokoya, Jun-Tao Wang, Hang-Wei Hu, Ji-Zheng He, Felipe Bastida, José L. Moreno, Adebola R. Bamigboye, Tine Grebenc, Tina Unuk Nahberger, 2021, izvirni znanstveni članek Povzetek: The structure and function of the soil microbiome of urban greenspaces remain largely undetermined. We conducted a global field survey in urban greenspaces and neighboring natural ecosystems across 56 cities from six continents, and found that urban soils are important hotspots for soil bacterial, protist and functional gene diversity, but support highly homogenized microbial communities worldwide. Urban greenspaces had a greater proportion of fast-growing bacteria, algae, amoebae, and fungal pathogens, but a lower proportion of ectomycorrhizal fungi than natural ecosystems. These urban ecosystems also showed higher proportions of genes associated with human pathogens, greenhouse gas emissions, faster nutrient cycling, and more intense abiotic stress than natural environments. City affluence, management practices, and climate were fundamental drivers of urban soil communities. Our work paves the way toward a more comprehensive global-scale perspective on urban greenspaces, which is integral to managing the health of these ecosystems and the well-being of human populations.
Ključne besede: soil biodiversity, structural diversity, functional diversity, urban soils
Objavljeno v DiRROS: 15.07.2021; Ogledov: 972; Prenosov: 822
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