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Classification and quantification of minor iron-sulfide concentrations in concrete aggregate using automated mineralogy
Full text linkIron sulfide concentrations and mineral associations triggering the internal deterioration of concrete structures are still enigmatic. Incidences of internal sulfate attacks induced by iron sulfide-containing concrete aggregates appear worldwide. Severe cases are reported from Canada, the United States of America, and Ireland. Moreover, conservative limits for the total sulfur content of aggregates increased the need to dispose of otherwise high-quality resources for concrete production. The maximum threshold values for total elemental sulfur in the European standard EN-12620 for concrete aggregates are 1 wt., and as little as 0.1 wt. if the non-stoichiometric iron-sulfide pyrrhotite (Fe(1-x)S) is present in the rock. This study investigates the potential of scanning electron microscopy-based automated mineralogy for mineral classification and the quantitative quality assessment for concrete aggregate material. Identifying the stoichiometrically closely related disulfide pyrite and monosulfide pyrrhotite is emphasized. The iron/sulfur ratio and greyscale variations in the electron backscatter images between pyrite and pyrrhotite were tested as additional differentiation criteria when acquiring mineral mapping and point-of-interest analysis. The added greyscale criterion yielded a better distinction between the two chemically similar phases. A good correlation was achieved when comparing results from energy-dispersive X-ray spectroscopy in automated mineralogy with wavelength-dispersive spectroscopy point analyses on the electron microprobe. Semi-quantification of the chemical data from automated mineralogy was computed for the total sulfur content in the petrographic samples. The total sulfur content of bulk samples, investigated by high-temperature combustion and inductively coupled plasma atomic emission spectroscopy, was consistent with the semi-quantitative results of automated mineralogy.publishedVersio
Energy retrofitting of heritage-protected buildings: Establishing representative case studies
Full text linkEurope aims to be carbon neutral by 2050. Efforts concerning the building stock are manifested in directives and programmes that aim to increase the renovation rate. While these efforts are a great starting point, there is a need for more research targeting heritage-protected buildings in cold climates. The challenge is that energy retrofitting and heritage protection are often looked at independently, while a combination is required to account for possible retrofitting limitations associated with buildings otherwise not part of energy-saving efforts. The main objective of the paper is to establish the energy retrofitting potential of buildings under heritage protection in Norway, on both national and local levels. Buildings are categorised according to their characteristics, including building typology, construction period, main construction materials, and heritage protection classes. The proposed workflow which highlights the most representative case studies required to retrofit the heritage-protected building stock, includes retrofitting measures, and a prediction of the overall effect on the respective building stock. Policymakers specifically can profit from the result that less than 10 case studies are required per covered building typology, locally and nationally, to account for more than half of the respective building stock. While the analyses cover buildings in Norway, the approach can be applied on an international scale analogously.publishedVersio
Developing whole-life carbon benchmark values for Norwegian buildings
Full text linkRecent years have seen an increased focus on reducing embodied greenhouse gas (GHG) emissions from buildings. This is exemplified by the race to develop national roadmaps and GHG limit values for buildings. In this study, 186 existing Norwegian LCA building case studies are collected, analyzed, and presented to ascertain WLC benchmark values for Norwegian buildings. The results are shown for different building typologies, per life cycle module, and per building part. The results also show the development of GHG emissions from Norwegian buildings over time and give a projection of GHG emission limit values towards 2030 and 2050. The results can be used by policy makers in the development of national roadmaps and WLC limit values for buildings.publishedVersio
Real-Time Norwegian Sign Language Recognition Using MediaPipe and LSTM
Full text linkThe application of machine learning models for sign language recognition (SLR) is a well-researched topic. However, many existing SLR systems focus on widely used sign languages, e.g., American Sign Language, leaving other underrepresented sign languages such as Norwegian Sign Language (NSL) relatively underexplored. This work presents a preliminary system for recognizing NSL gestures, focusing on numbers 0 to 10. Mediapipe is used for feature extraction and Long Short-Term Memory (LSTM) networks for temporal modeling. This system achieves a testing accuracy of 95%, aligning with existing benchmarks and demonstrating its robustness to variations in signing styles, orientations, and speeds. While challenges such as data imbalance and misclassification of similar gestures (e.g., Signs 3 and 8) were observed, the results underscore the potential of our proposed approach. Future iterations of the system will prioritize expanding the dataset by including additional gestures and environmental variations as well as integrating additional modalities.publishedVersio
Flexibility in electricity distribution grids : white paper (CINELDI report 02:2025)
No full textpublishedVersio
Transition scenarios for conversion to net-carbon-neutral fishing vessels
Full text linkSINTEF Ocean has conducted a review of published reports on transition scenarios for the conversion of fishing vessels to net-carbon-neutral vessels. The scenarios analysis concludes that the ultimate goal of carbon-neutral fishing vessels can be met, but that the direct use of hydrogen will play a neglectable role to obtain such ambitious targets.
The memo explains basic constraints related to hydrogen properties and hydrogen fuel systems, as well as their impacts on costs and feasibility as a fuel for fishing vessels. These challenges explain why other carbon-neutral fuels are expected to be dominant in meeting future emission targets.publishedVersio
Framework for Combined Life Cycle Environmental, Economic, and Social Assessment of Reclaimed Construction Products
Full text linkA relevant approach to limit virgin materials consumption and waste in the construction industry is to use reclaimed construction products. Their sustainability performance depends on various parameters, including the activities needed to reuse them. Currently, the life cycle sustainability assessment (LCSA) of reclaimed products is conducted following various methods and assumptions, which are not always transparently communicated. There is also limited consideration of other sustainability indicators beyond initial cost and greenhouse gas (GHG) emissions. Therefore, we developed a harmonized Excel-based LCSA framework for evaluating and comparing side-by-side the life cycle environmental (LCA), economic (LCC), and social (S-LCA) impacts of reclaimed and new construction products. This chapter presents the LCSA framework and how it can be applied in practice, with the comparative evaluation of a pavement in Oslo, Norway, with new and reclaimed paving stones. The LCSA framework shows it is possible to harmonize the various assessment methods and expand the scope of product assessment from purely GHG emissions to overall sustainability. The results of the pavement assessment show that reuse can bring lower environmental and social impacts, although it currently costs more to the user. The LCSA framework can be tested by experts in one or more life cycle approaches to guide different actors in the reuse value chain (e.g., product resellers and architects).publishedVersio
A Comparative Study of UCS Results Obtained from Triaxial Tests Under Multiple Failure State Conditions (Test Type II)
Full text linkIn any rock engineering project, the uniaxial compressive strength (UCS) is one of the most relevant parameters to be determined as it is used for a variety of purposes. Traditionally, the UCS of a rock sample is obtained by carrying out a uniaxial test on a rock core. The UCS can also be estimated indirectly by correlating it with different parameters such as the pulse velocity (Vp), Schmidt hammer rebound number (Rn), effective porosity (ne), total porosity (nt), dry density (γd), point load index (Is50), shear wave velocity (Vs), Brazilian tensile strength (BTS), slake durability index (SDI), or by using an artificial neural network (ANN). This paper presents a comparative study for an additional approach to determine the UCS, namely by converting triaxial test results to the UCS. This research has been conducted to encourage further utilisation of laboratory test results obtained from triaxial tests. Triaxial tests are normally performed to determine the intact rock strength envelope. By further utilisation of triaxial test data to estimate the UCS, the database of the UCS can be enriched for rock engineering projects. The method can also be used in cases of limited samples or when samples are too challenged for carrying out a USC test. The research showed that the UCS derived by this method is more direct and more accurate than many empirical methods. Furthermore, the test procedure described herein (carrying out the UCS and triaxial tests on the same sample) can be used to evaluate the accuracy of the calculated UCS. It is important to bear in mind that the scope of this study is not to develop a new method or replace the traditional uniaxial compression test with the method presented in this paper. The purpose and intention is to document that the test results obtained from triaxial testing can be utilised to also provide values of UCS from the same samples.publishedVersio
Sikkerhetstiltak for fiskeflåten - Interessenter, årsakskart for personulykker og tiltaksforslag
Full text linkRapporten presenterer sikkerhetstiltak for fiskeflåten. Arbeidet er basert på tre hovedaktiviteter:
1. Beskrivelse av interesser som direkte eller indirekte kan påvirke sikkerheten i fiskeflåten
2. Årsaksanalyse av ulykkeshendelser og
3. Tiltaksutforming.
Interessentene som beskrives er: fiskeren, opplæringsaktører og kunnskapsleverandører, tjeneste- og utstyrsleverandører, offentlige instanser, beredskapsaktører, premissgivere og interesseorganisasjoner.
Det presenteres årsakskart og forslag til tiltak for fem ulykkeshendelser: forlis, fisker over bord, fall om bord, slag-/klemulykker og drukning i havn. Tiltakskategorier er arbeidspraksis, arbeidsplass, arbeidsbekledning og personlig verneutstyr, opplæring og kompetanse og rammebetingelser og regulering