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504. Differences in distribution and characteristics of microplastics in sediments of the south-eastern part of the Gulf of TriesteJena Jamšek, Helena Prosen, Oliver Bajt, 2024, original scientific article Abstract: Introduction: The Gulf of Trieste is prone to the accumulation of various pollutants and microplastics due to its geomorphological and hydrological characteristics. However, the distribution and sources of microplastics in this semi-enclosed area are poorly studied. The aim of our study was to determine the distribution and chemical composition of MP particles in the sediments of the Gulf of Trieste. Methods: In this study, we collected 24 surface sediment samples using a Van Veen grab. Microplastics were extracted by density separation using NaCl. The size, shape, and color of the extracted microplastics were determined using an optical microscope, and the composition of the polymers was determined by Fourier transform infrared spectroscopy. Results and discussion: The highest concentrations of up to 125 microplastic particles per 100 g dry sediment were found in coastal areas. Concentrations in the open sea were much lower, with an average of 3 particles per 100 g of sediment. Most of the microplastic was fibrous, made of polypropylene, 100–300 µm in size, and blue. This is the first study showing that microplastics are present in the sediments of the south-eastern part of the Gulf of Trieste. The findings suggest that microplastics exhibit a tendency to be retained within the sediment, leading to their accumulation primarily in a narrow coastal area rather than dispersing offshore. Our results will contribute to a better knowledge of the distribution and possible sources of plastics and microplastics in the Gulf of Trieste and even beyond in similar semi-enclosed marine areas.
Keywords: microplastics, sediments, Gulf of Trieste, density separation, polypropylene, accumulation of pollutants, marine biology
Published in DiRROS: 23.10.2024; Views: 145; Downloads: 983
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505. How to create a national sport strategy : a substantive and methodological perspectiveEdvard Kolar, Elnur E. Mammadov, Farid F. Gayibov, Mariana T. Vasileva, Roberto Biloslavo, Rado Pišot, 2024, original scientific article Abstract: Purpose: Due to its numerous positive effects on individuals and society as a whole, sport has become an important socio-economic subsystem of the national environment. To regulate, develop, and monitor the impact of sport at national, regional, and local levels, countries often develop and adopt various strategic documents, which can be found under the name of national program or strategy for sport development at the na-tional level. Due to the importance of understanding the substantial comprehensiveness of national sports strategies (NSS) and the precision of the methodological-processual approach, the purpose of the present paper is to present a methodological and sub-stantive view of the process of creating NSS and to develop a comprehensive concept (model) that appropriately places the substantive part in the phases of the process.Method: The methodology of writing conceptual research papers was used. This approach provides a bridge or link between different concepts and scientific discipli-nes. The methodological approach was the “model paper” which aims to provide a theoretical framework that predicts relationships between concepts. A model paper identifies connections between constructs and introduces new constructs.Findings: The development of the substantive model for the preparation of the NSS revealed that the comprehensive sport system at the national level can be understood within the framework of five substructures (financial, organizational, developmental, material, and program) that contribute significantly to the development and implemen-tation of activities related to sport and physical activity. They are interconnected and interdependent and are surrounded by a so-called integrity framework that protects the sport system from the deviations of modern society. The methodological process model reveals that for the implementation of the process of NSS preparation, the most appro-priate is the strategic management methodology, which enables accurate and efficient management of planning, organization, implementation, and control of the NSS. The combination of both perspectives (substantive and methodological) enables the deve-lopment of a comprehensive concept (model) of NSS preparation.Conclusions: The developed concept (model) of the NSS preparation comprehen-sively covers the issue of the NSS preparation management and is dialectical, open, flexible, and repeatable, enabling future users to manage the NSS preparation in a substantive-holistic and process-effective manner.
Keywords: methodological perspective, national sport strategy, preparation, substantive perspective
Published in DiRROS: 23.10.2024; Views: 125; Downloads: 63
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506. Mutual-visibility and general position in double graphs and in MycielskiansDhanya Roy, Sandi Klavžar, Aparna Lakshmanan S., 2025, original scientific article Abstract: The general position problem in graphs is to find the largest possible set of vertices with the property that no three of them lie on a common shortest path. The mutual-visibility problem in graphs is to find the maximum number of vertices that can be selected such that every pair of vertices in the collection has a shortest path between them with no vertex from the collection as an internal vertex. Here, the general position problem and the mutual-visibility problem are investigated in double graphs and in Mycielskian graphs. Sharp general bounds are proved, in particular involving the total and the outer mutual-visibility number of base graphs. Several exact values are also determined, in particular the mutual-visibility number of the double graphs and of the Mycielskian of cycles.
Keywords: general position, mutual-visibility, double graph, Mycielskian graph, outer mutual-visibility, total mutual-visibility
Published in DiRROS: 23.10.2024; Views: 115; Downloads: 60
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507. Materiali in tehnologije2000, not set Abstract: Materiali in tehnologije (MIT) je mednarodna, recenzirana in odprtodostopna revija. Revija omogoča objave izvirnih znanstvenih člankov in preglednih člankov s področja kovinskih in anorganskih materialov, polimerov, nanomaterialov, metalurgije in vakuumske tehnike. Revija izhaja šestkrat letno v tiskani in elektronski obliki.
Keywords: materiali, metalurgija, kovine, zlitine, nanomateriali, polimeri
Published in DiRROS: 22.10.2024; Views: 165; Downloads: 90
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510. Animal life in the shallow subseafloor crust at deep-sea hydrothermal ventsMonika Bright, Sabine Gollner, André Luiz de Oliveira, Salvador Espada-Hinojosa, Avery Fulford, Tihomir Makovec, Tinkara Tinta, 2024, original scientific article Abstract: It was once believed that only microbes and viruses inhabited the subseafloor crust beneath hydrothermal vents. Yet, on the seafloor, animals like the giant tubeworm Riftia pachyptila thrive. Their larvae are thought to disperse in the water column, despite never being observed there. We hypothesized that these larvae travel through the subseafloor via vent fluids. In our exploration, lifting lobate lava shelves revealed adult tubeworms and other vent animals in subseafloor cavities. The discovery of vent endemic animals below the visible seafloor shows that the seafloor and subseafloor faunal communities are connected. The presence of adult tubeworms suggests larval dispersal through the recharge zone of the hydrothermal circulation system. Given that many of these animals are host to dense bacterial communities that oxidize reduced chemicals and fix carbon, the extension of animal habitats into the subseafloor has implications for local and regional geochemical flux measurements. These findings underscore the need for protecting vents, as the extent of these habitats has yet to be fully ascertained.
Keywords: subseafloor, hydrothermal vents, tubeworms, larvae, vent fluids, bacterial communities, geochemical flux, geochemistry, marine biology
Published in DiRROS: 22.10.2024; Views: 149; Downloads: 949
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