| 1. |
- Jönsson, Martin, et al.
(författare)
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Corrosion product formation during NaCl induced atmospheric corrosion of magnesium alloy AZ91D
- 2007
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 49:3, s. 1540-1558
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Tidskriftsartikel (refereegranskat)abstract
- Magnesium alloy AZ91D was exposed in humid air at 95% relative humidity (RH) with a deposition of 70 μg/cm-2 NaCl. The corrosion products formed and the surface electrolyte were analysed after different exposure times using ex situ and in situ FTIR spectroscopy, X-ray diffraction and Ion Chromatography. The results show that magnesium carbonates are the main solid corrosion products formed under these conditions. The corrosion products identified were the magnesium carbonates hydromagnesite (Mg5 (CO3)4 (OH)24H2O) and nesquehonite (MgCO3 3H2O). The corrosion attack starts with the formation of magnesite at locations with higher NaCl contents. At 95% RH, a sequence of reactions was observed with the initial formation of magnesite, which transformed into nesquehonite after 2-3 days. Long exposures result in the formation of pits containing brucite (Mg(OH2)) covered with hydromagnesite crusts. The hydromagnesite crusts restrict the transport of CO2 and O2 to the magnesium surface and thereby favour the formation of brucite. Analysis of the surface electrolyte showed that the NaCl applied on the surface at the beginning was essentially preserved during the initial corrosion process. Since the applied salt was not bound in sparingly soluble corrosion products a layer of NaCl electrolyte was present on the surface during the whole exposure. Thus, Na+ and Cl- ions can participate in the corrosion process during the whole time and the availability of these species will not restrict the atmospheric corrosion of AZ91D under these conditions. It is suggested that the corrosion behaviour of AZ91D is rather controlled by factors related to the microstructure of the alloy and formation of solid carbonate containing corrosion products blocking active corrosion sites on the surface.
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| 4. |
- Bäckström, Daniel, 1985, et al.
(författare)
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Particle composition and size distribution in coal flames - The influence on radiative heat transfer
- 2015
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Ingår i: Experimental Thermal and Fluid Science. - : Elsevier BV. - 0894-1777 .- 1879-2286. ; 64, s. 70-80
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Tidskriftsartikel (refereegranskat)abstract
- Radiative heat transfer in a 77 kWth swirling lignite flame has been studied. The aim is to characterize different particle types present in a coal flame and to determine their influence on the radiative heat transfer. The study combines extractive particle measurements, radiative intensity measurements and detailed radiation modelling. The size distribution of the extracted particles was measured with a low pressure impactor and some of the size fractions were analysed with SEM–EDX. The measured total radiative intensity is compared with the modelled intensity based on the particle measurements in the same cross-section of the flame. The particle properties were calculated with Mie theory and the gas properties with a statistical narrow-band model. The results show that the contribution of coal/char particles dominates the radiative heat transfer in the investigated cross-section of the flame. The methodology applied in this work shows promising results for characterization of particle radiation in flames of practical size.
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| 5. |
- Frisk, Karin, et al.
(författare)
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Characterisation of EBM-built shelled samples of Ti6Al4V compacted by HIP
- 2016
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Ingår i: World PM 2016 Congress and Exhibition. - : European Powder Metallurgy Association (EPMA). - 9781899072484
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Konferensbidrag (refereegranskat)abstract
- Compaction of additively manufactured Ti6Al4V components by Hot Isostatic Pressing (HIP) is often applied to eliminate porosity, producing fully dense material. In the present work shelled samples produced by Electron Beam Melting with the Arcam process (EBM) were compacted by HIP to produce fully dense samples. Cylindrical samples were studied. The walls of the cylinders were built with EBM, and the powder from the process was left uncompacted inside the cylinders. Samples with different wall thicknesses were produced. The samples were thereafter subjected to a HIP compaction. The critical wall thicknesses needed for compaction were evaluated, and the microstructures characterized. The results show that fully dense samples, with very fine microstructures, are possible.
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| 6. |
- Gåsvaer, Daniel, et al.
(författare)
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Att utveckla den smarta svetscellen : Lean, svetsteknik och automation
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- En svetscell producerar och är produktiv när svetsning pågår och ljubågen brinner. Då skapas värde i en svetscell. För att nå teknisk och ekonomisk framgång, behöver svetscellen fungera "smart" med effektiva flöden, hög tillgänglighet, optimerad svetsteknik och ur flera aspekter goda miljöegenskaper. Skriften fungerar som hjälp när företag vill utveckla sin svetsverkstad och förbättra svetsproduktionen, utifrån lean, svetsteknik och automation.
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| 7. |
- Landberg, Göran, et al.
(författare)
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Characterization of cell-free breast cancer patient-derived scaffolds using liquid chromatography-mass spectrometry/mass spectrometry data and RNA sequencing data
- 2020
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Ingår i: Data in Brief. - : Elsevier BV. - 2352-3409. ; 31
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Tidskriftsartikel (refereegranskat)abstract
- Patient-derived scaffolds (PDSs) generated from primary breast cancer tumors can be used to model the tumor microenvironment in vitro . Patient-derived scaffolds are generated by repeated detergent washing, removing all cells. Here, we analyzed the protein composition of 15 decellularized PDSs using liquid chromatography-mass spectrometry/mass spectrometry. One hundred forty-three proteins were detected and their relative abundance was calculated using a reference sample generated from all PDSs. We performed heatmap analysis of all the detected proteins to display their expression patterns across different PDSs together with pathway enrichment analysis to reveal which processes that were connected to PDS protein composition. This protein dataset together with clinical information is useful to investigators studying the microenvironment of breast cancers. Further, after repopulating PDSs with either MCF7 or MDA-MB-231 cells, we quantified their gene expression profiles using RNA sequencing. These data were also compared to cells cultured in conventional 2D conditions, as well as to cells cultured as xenografts in immune-deficient mice. We investigated the overlap of genes regulated between these different culture conditions and performed pathway enrichment analysis of genes regulated by both PDS and xenograft cultures compared to 2D in both cell lines to describe common processes associated with both culture conditions. Apart from our described analyses of these systems, these data are useful when comparing different experimental model systems. Downstream data analyses and interpretations can be found in the research article "Patient-derived scaffolds uncover breast cancer promoting properties of the microenvironment" [1] . (C) 2020 The Authors. Published by Elsevier Inc.
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| 8. |
- Landberg, Göran, et al.
(författare)
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Patient-derived scaffolds uncover breast cancer promoting properties of the microenvironment
- 2020
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Ingår i: Biomaterials. - : Elsevier Ltd. - 0142-9612 .- 1878-5905. ; 235
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Tidskriftsartikel (refereegranskat)abstract
- Tumor cells interact with the microenvironment that specifically supports and promotes tumor development. Key components in the tumor environment have been linked to various aggressive cancer features and can further influence the presence of subpopulations of cancer cells with specific functions, including cancer stem cells and migratory cells. To model and further understand the influence of specific microenvironments we have developed an experimental platform using cell-free patient-derived scaffolds (PDSs) from primary breast cancers infiltrated with standardized breast cancer cell lines. This PDS culture system induced a series of orchestrated changes in differentiation, epithelial-mesenchymal transition, stemness and proliferation of the cancer cell population, where an increased cancer stem cell pool was confirmed using functional assays. Furthermore, global gene expression profiling showed that PDS cultures were similar to xenograft cultures. Mass spectrometry analyses of cell-free PDSs identified subgroups based on their protein composition that were linked to clinical properties, including tumor grade. Finally, we observed that an induction of epithelial-mesenchymal transition-related genes in cancer cells growing on the PDSs were significantly associated with clinical disease recurrences in breast cancer patients. Patient-derived scaffolds thus mimics in vivo-like growth conditions and uncovers unique information about the malignancy-inducing properties of tumor microenvironment. © 2019 The Authors
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| 9. |
- Le Bozec, Nathalie, et al.
(författare)
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The role of chromate conversion coating in the filiform corrosion of coated aluminum alloys
- 2003
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 150:12, s. B561-B566
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Tidskriftsartikel (refereegranskat)abstract
- The mechanisms of inhibition of chromate conversion coating on the filiform corrosion of coated aluminum alloy AA6016 was investigated using X-ray absorption near-edge structure (XANES) spectroscopy and Raman microspectroscopy. The results showed that Cr(VI) was preferably leached out at the opening of the filament, whereas Cr(VI) was reduced to Cr(III) at all other locations. The leached out Cr(VI) accumulated mainly in the pitting area, located in the scratch just outside the filament. The chromate released from the CCC was partly reduced to Cr(III) in the pit. The formation of an Al/Cr mixed oxide was observed in the pitting area. The repassivation of pits in the scratch by the chromate leaching from the CCC close to the scratch explains the low propagation of filiform corrosion observed for the chromated surfaces.
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| 10. |
- LeBozec, Nathalie, et al.
(författare)
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Application of scanning Kelvin probe, XANES and FTIR microspectroscopy for investigating the mechanisms of filiform corrosion on coated aluminium alloys
- 2004
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Ingår i: EUROCORR 2004 - European Corrosion Conference.
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Konferensbidrag (refereegranskat)abstract
- Filiform corrosion is an active corrosion cell that moves across the metal surface underneath the coating, leaving a tail filled with corrosion products. Filiform corrosion is a main problem on coated aluminium alloys exposed to a humid atmosphere. The corrosion is generally initiated in defects in the coating and propagates in presence of aggressive ions (chloride, sulphate...), oxygen and sufficient relative humidity. The aim of this investigation is to provide more information on the mechanism of filiform corrosion on coated aluminium alloys using complementary localized techniques: the scanning Kelvin probe (SKP), the Fourier Transformed Infra-Red (FTIR) microspectroscopy and X-ray absorption near-edge structure (XANES) technique. SKP can provide information on the potential distribution during corrosion processes on both bare and coated metals with a spatial resolution of approximately 50 μm. Here, SKP measurements have been performed in order to identify the anodic and cathodic sites on filaments formed on coated aluminium during atmospheric exposure. FTIR microspectroscopy permits the identification of thin surface films of corrosion products both under ex-situ and in-situ conditions. As the spatial resolution is similar to the SKP, this technique has provided information on the composition of corrosion products formed in the head and in the tail of the filaments. The initiation and the propagation of filiform corrosion on coated aluminium alloy were investigated using an experimental set-up for in-situ infrared reflection absorption spectroscopy. It consisted of an in-situ cell, where samples were exposed to controlled humid conditions, and an optical microscope linked with a Fourier Transformed Spectrometer. XANES measurements were performed on coated chromated aluminium alloys in order to study the mechanisms of inhibition of chromate on the filiform corrosion. This was performed using a high resolution beam (e.g. 15-35 μm), making possible the establishment of X-ray maps of Cr(VI) and total chromium over the surface including the filament.
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