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Povzetek: Multi-material components, also known as functionally graded materials (FGMs), are innovative materials that possess unique properties due to their composition and have many potential applications in engineering and science. The effect of the heat treatment (HT) of functionally graded materials 15–5 precipitation-hardened (PH) martensitic steel and SAF 2507 duplex stainless steel (and the opposite order of deposition, i.e. SAF 2507 first followed by 15–5 PH stainless steel) on the interface microstructures was systematically investigated in the presented research. The choice of HT followed the trend of optimum post-processing for the individual alloys. A significant modification in the interface microstructure, characterized in the microstructural transition zone (MTZ) formed above the fusion line. Mechanical properties by miniaturized testing method including hardness measurement characterized both types of interfaces. The sequence of the materials’ application did not have a significant effect on their final mechanical tensile properties in the heat-treated states. Nevertheless, the microstructural change at the MTZ led to drop in the hardness at the interface. The research presents heat-treated FGMs in a horizontal configuration to form a high-quality metallurgical joint between heterogeneous materials manufactured by powder-based directed energy deposition method.
Ključne besede: heat treatment, additive manufacturing, martensitic stainless steel, duplex steel, microstructure, mechanical properties
Objavljeno v DiRROS: 04.04.2024; Ogledov: 53; Prenosov: 11
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Povzetek: As we spend more than 90% of our time inside buildings, indoor environmental quality is a major concern for healthy living. Recent studies show that almost 80% of people in European countries and the United States suffer from SBS (Sick Building Syndrome), which affects physical health, productivity and psychological well-being. In this context, environmental quality monitoring provides stakeholders with crucial information about indoor living conditions, thus facilitating building management along its lifecycle, from design, construction and commissioning to usage, maintenance and end-of-life. However, currently available modelling tools for building management remain limited to static models and lack integration capacities to efficiently exploit environmental quality monitoring data. In order to overcome these limitations, we designed and implemented a generic software architecture that relies on accessible Building Information Model (BIM) attributes to add a dynamic layer that integrates environmental quality data coming from deployed sensors. Merging sensor data with BIM allows creation of a digital twin for the monitored building where live information about environmental quality enables evaluation through numerical simulation. Our solution allows accessing and displaying live sensor data, thus providing advanced functionality to the end-user and other systems in the building. In order to preserve genericity and separation of concerns, our solution stores sensor data in a separate database available through an application programming interface (API), which decouples BIM models from sensor data. Our proof-of-concept experiments were conducted with a cultural heritage building located in Bled, Slovenia. We demonstrated that it is possible to display live information regarding environmental quality (temperature, relative humidity, CO2, particle matter, light) using Revit as an example, thus enabling end-users to follow the conditions of their living environment and take appropriate measures to improve its quality
Ključne besede: Building Information Model, internet of things, environmental quality monitoring, healthy living
Objavljeno v DiRROS: 19.01.2024; Ogledov: 163; Prenosov: 75
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Povzetek: For non-native tree species with an origin outside of Europe a detailed compilation of enemy species including the severity of their attack is lacking up to now. We collected information on native and non-native species attacking non-native trees, i.e. type, extent and time of first observation of damage for 23 important non-native trees in 27 European countries. Our database includes about 2300 synthesised attack records (synthesised per biotic threat, tree and country) from over 800 species. Insects (49%) and fungi (45%) are the main observed biotic threats, but also arachnids, bacteria including phytoplasmas, mammals, nematodes, plants and viruses have been recorded. This information will be valuable to identify patterns and drivers of attacks, and trees with a lower current health risk to be considered for planting. In addition, our database will provide a baseline to which future impacts on non-native tree species could be compared with and thus will allow to analyse temporal trends of impacts.
Objavljeno v DiRROS: 21.02.2022; Ogledov: 606; Prenosov: 678
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Povzetek: Wood resources have been essential for human welfare throughout history. Also nowadays, the volume of growing stock (GS) is considered one of the most important forest attributes monitored by National Forest Inventories (NFIs) to inform policy decisions and forest management planning. The origins of forest inventories closely relate to times of early wood shortage in Europe causing the need to explore and plan the utilisation of GS in the catchment areas of mines, saltworks and settlements. Over time, forest surveys became more detailed and their scope turned to larger areas, although they were still conceived as stand-wise inventories. In the 1920s, the first sample-based NFIs were introduced in the northern European countries. Since the earliest beginnings, GS monitoring approaches have considerably evolved. Current NFI methods differ due to country-specific conditions, inventory traditions, and information needs. Consequently, GS estimates were lacking international comparability and were therefore subject to recent harmonisation efforts to meet the increasing demand for consistent forest resource information at European level. As primary large-area monitoring programmes in most European countries, NFIs assess a multitude of variables, describing various aspects of sustainable forest management, including for example wood supply, carbon sequestration, and biodiversity. Many of these contemporary subject matters involve considerations about GS and its changes, at different geographic levels and time frames from past to future developments according to scenario simulations. Due to its historical, continued and currently increasing importance, we provide an up-to-date review focussing on large-area GS monitoring where we i) describe the origins and historical development of European NFIs, ii) address the terminology and present GS definitions of NFIs, iii) summarise the current methods of 23 European NFIs including sampling methods, tree measurements, volume models, estimators, uncertainty components, and the use of air- and space-borne data sources, iv) present the recent progress in NFI harmonisation in Europe, and v) provide an outlook under changing climate and forest-based bioeconomy objectives.
Ključne besede: forest history, natural resources, sustainability, timber volume, sampling, remote sensing, bioeconomy, climate change
Objavljeno v DiRROS: 14.12.2021; Ogledov: 764; Prenosov: 544
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