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- Minelli, Caterina, et al.
(författare)
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Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles
- 2022
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 14, s. 4690-4704
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Tidskriftsartikel (refereegranskat)abstract
- We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles.
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| 2. |
- Veljkovic, Milan, et al.
(författare)
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High-strength tower in steel for wind turbines (Histwin) : Final report
- 2012
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Rapport (refereegranskat)abstract
- Innovative solutions for assembling joints of a tubular tower for wind turbines were studied and the project provides a background for design. This solution is simpler to produce and 80 % less expensive than traditional flange connection. Our feasibility study at the production plant indicates that the towers would be easy to assemble in situ. In addition to the direct cost savings due to the technical simplicity of the solution, the higher fatigue endurance than that of the flange connection is experimentally established. Further reduction of costs due to optimal use of higher-strength steel grades, especially in the bottom segments of the tower where the stiffening of the door opening is costly, is shown in the report. The total reduction of the costs for tower is estimated at about 10–15 % compared to the traditional tower. The project objectives are achieved in following sequences. • Experimental activities of the friction connection: small-scale tests to establish resistance of the friction connection for a variety of faying surfaces and bolt types, accompanying testing to ensure realistic input data for FEA, long-term testing to establish loss of pretension forces during the lifetime and fatigue tests.• Bending test of the friction and flange connection in a down-scaled tower. • Feasibility of production of the tower segments in the laboratory and at the production plant. • Monitoring of the existing tower to access a stress variation during the operation. • FEA analysis of experimental results and a complete case study of the monitored tower. Numerical examples for design of the friction connection are given for the sake of illustration and to encourage use of the new connection
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| 3. |
- Malmi, L., et al.
(författare)
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Developing a methodological taxonomy of EER papers
- 2012
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Ingår i: SEFI 40th Annual Conference 2012; Thessaloniki; Greece; 23 September 2012 through 26 September 2012. - 9782873520052
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Konferensbidrag (refereegranskat)abstract
- Engineering Education Research (EER) is a wide and rich field of investigation [1]. It covers research on learning and teaching in all engineering disciplines as well as in the supporting disciplines, like physics, chemistry, computing and mathematics, which form the scientific basis of engineering research. Moreover, EER draws on theories and research methodologies from social sciences, like education, psychology and sociology to investigate the many-faced aspects of learning and teaching engineering. In order to get a better overview of the whole field, there is a need to look at both what is being researched and how the research is carried out. The authors of this paper met in connection to a series of meetings arranged by the SEFI working group EER and a series of workshops organised by Line B of the EU project EUGENE, and decided to collaborate on the construction of a taxonomy for EER from a European perspective. The overall aim is to develop a taxonomy for the how aspect of EER. More specifically, we aim to identify what kind of theoretical frameworks and research designs that are being used, what kind of data that is collected and how it is analysed in EER papers. Our current analysis focuses on published papers in two major European EER forums: European Journal of Engineering Education and the EER track in the SEFI conference, but the taxonomy can obviously be used to analyse any other EER papers. We hope that this work will better reveal the richness of the field, but also highlight approaches that could be used more often in EER. Moreover, the results can be used to inform authors about differences between various publication forums, and emerging methodological trends in research. Finally, we will also look at how different aspects of research have been reported in EER papers with a view to providing suggestions for improving research reporting. In this paper we describe the taxonomy and how it was developed. The results of the analysis will be reported elsewhere.
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