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| 2. |
- Girlanda, Orlando, et al.
(författare)
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Analysis of the Micromechanical Deformation in Pressboard performed by X-ray Microtomography
- 2015
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Ingår i: IEEE Electrical Insulation Conference (EIC). - Piscataway, NJ : IEEE Communications Society. - 9781479973545 ; , s. 89-92
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Konferensbidrag (refereegranskat)abstract
- A large number of electrical insulation components are produced in paper-based materials. Paper combines good insulating properties with the necessary mechanical and chemical stability. Paper consists of a system of fibers binding to each other creating a strong network. The presence of large open pores allows for impregnability of the material but also causes mechanical weakness in particular in the out-of-plane direction of the material. This aspect is important for pressboard components, where the resistance to compression stress is relevant for e.g. transformer windings. It is therefore relevant to understand the mechanisms that underlay the out-of-plane deformation of pressboard. In order to get a clear picture of the deformation patterns within the material, X-ray micro-computed tomography was used. Pressboard test pieces were subjected to in-situ out-of-plane compressive loading. 3D images of the sample could be captured before, during and after the loading sequence. Image analysis allowed for the definition of strain fields. The results revealed a strong correlation between the density variation within the sample and the strain calculated from the 3D images.
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| 3. |
- Innings, Fredrik, et al.
(författare)
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Understanding and analysis of wear in homogenizers for processing liquid food
- 2011
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Ingår i: Wear. - : Elsevier BV. - 0043-1648 .- 1873-2577. ; 271:9-10, s. 2588-2598
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Tidskriftsartikel (refereegranskat)abstract
- The tribological research pertaining to homogenizers in processing liquid food has received much less attention compared to its potential in enhancing the efficiency and durability of the homogenization process equipment. Homogenization is a process used to disrupt fat globules in dairy products to reduce the formation of creamy layer (separation) and also to enhance the viscosity of certain products. This process takes place in a narrow gap in the homogenizer machine and this region is highly prone to wear. The occurrence of wear during processing not only impairs the homogenization effect but also leads to increased downtime of the machine. The aim of this work is to understand the occurrence of wear and wear mechanisms in the homogenization gap using both experimental and analytical approaches. Two experimental test rigs were used to study the differences in wear during operation, i.e. with and without particles. The trajectories of the particles have been simulated without the influence of cavitation using a CFD-code to investigate whether the particles are the cause of wear. The homogenizer gap has been simulated for a worn geometry to see how the occurrence of wear changes the particles trajectories. The results have shown that the presence of particles accelerates wear and most important parameters are the particle hardness and mass. When cavitation and particles are combined they create a synergistic effect on wear. This can be explained by the fact that cavitation can accelerate particles in random directions through the imploding action of cavities. A change in impact angle and increased velocity increases the amount of wear significantly. CFD-simulations and calculations show that the particles do not fully follow the streamlines and therefore create wear on the gap surfaces.
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| 4. |
- Joffre, Thomas, 1987-, et al.
(författare)
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A 3D in-situ investigation of the deformation in compressive loading in the thickness direction of cellulose fiber mats
- 2015
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Ingår i: Cellulose. - : Springer Science and Business Media LLC. - 0969-0239 .- 1572-882X. ; 22:5, s. 2993-3001
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Tidskriftsartikel (refereegranskat)abstract
- Fiber mat materials based on cellulose natural fibers combines a useful set of properties, including renewability, stiffness, strength and dielectric insulation, etc. The dominant in-plane fiber orientation ensures the in-plane performance, at the expense of reduced out-of-plane behavior, which has not been studied as extensively as the in-plane behavior. Quantitative use of X-ray micro-computed tomography and strain analyses under in-situ loading open up possibilities to identify key mechanisms responsible for deformation. In the present investigation, focus is placed on the out-of-plane deformation under compressive loading of thick, high density paper, known as pressboard. The samples were compressed in the chamber of a microtomographic scanner. 3D images were captured before and after the loading the sample. From sequential 3D images, the strain field inside the material was calculated using digital volume correlation. Two different test pieces were tested, namely unpolished and surface polished ones. The first principal strain component of the strain tensor showed a significant correlation with the density variation in the material, in particular on the top and bottom surfaces of unpolished samples. The manufacturing-induced grooves generate inhomogeneities in the microstructure of the surface, thus creating high strain concentration zones which give a sensible contribution to the overall compliance of the unpolished material. More generally, the results reveal that, on the micrometer scale, high density fiber pressboard behaves as a porous material rather than a low density fiber network.
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| 5. |
- Karlsson (Hillmering), Mikael, 1982-, et al.
(författare)
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High-resolution micropatterning of off-stochiometric thiol-enes (OSTE) via a novel lithography mechanism
- 2012
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Ingår i: 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences (microTAS 2012). ; , s. 225-227
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Konferensbidrag (refereegranskat)abstract
- We present an entirely novel, self-limiting photolithography mechanism in off-stoichiometry thiol-ene (OSTE) polymers enabling high-resolution and high-aspect ratio features. The OSTE polymers have previously been shown to be promising materials for fabrication of microfluidic devices with tailored surface modifications and mechanical properties. We here introduce direct lithography for micropatterning of OSTE as an alternative to mechanical machining or casting, resulting in a simple and reliable fabrication method of self-bonding photopatterned multilayer microfluidic devices.
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| 6. |
- Karlsson, Max, et al.
(författare)
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Genome-wide single cell annotation of the human protein-coding genes
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- An important quest for the life science community is to deliver a complete annotation of the human building-blocks of life, the genes and the proteins. Here, we report on a genome-wide effort to annotate all protein-coding genes based on single cell transcriptomics data representing all major tissues and organs in the human body, integrated with data from bulk transcriptomics and antibody-based tissue profiling. Altogether, 25 tissues have been analyzed with single cell transcriptomics resulting in genome-wide expression in 444 single cell types using a strategy involving pooling data from individual cells to obtain genome-wide expression profiles of individual cell type. We introduce a new genome-wide classification tool based on clustering of similar expression profiles across single cell types, which can be visualized using dimensional reduction maps (UMAP). The clustering classification is integrated with a new “tau” score classification for all protein-coding genes, resulting in a measure of single cell specificity across all cell types for all individual genes. The analysis has allowed us to annotate all human protein-coding genes with regards to function and spatial distribution across individual cell types across all major tissues and organs in the human body. A new version of the open access Human Protein Atlas (www.proteinatlas.org) has been launched to enable researchers to explore the new genome-wide annotation on an individual gene level.
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| 7. |
- Larsson, Jimmy, et al.
(författare)
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Nuclear receptor binding protein 2 is induced during neural progenitor differentiation and affects cell survival
- 2008
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Ingår i: Molecular and Cellular Neuroscience. - : Elsevier BV. - 1044-7431 .- 1095-9327. ; 39:1, s. 32-9
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Tidskriftsartikel (refereegranskat)abstract
- We previously identified nuclear receptor binding protein 2 (NRBP2) in a screen for genes induced by differentiation of neural stem/progenitor cells. Here we show that during embryonic mouse brain development NRBP2 was expressed in the walls of the third and fourth ventricles, and in the hippocampus. In the adult brain, Purkinje cells of the cerebellum and neurons in the CA3 region of the hippocampus were main sites of NRBP2 expression. Analysis of a pediatric medulloblastoma showed that clusters of NRBP2 positive tumor cells co-expressed neurofilament, but not GFAP. Thus, NRBP2 was associated with neuronal differentiation both in normal and malignant brain tissue. We report that NRBP2 is a 55-60 kDa protein with mainly cytoplasmic location. In vitro, NRBP2 protein levels increased as neural stem/progenitor cells differentiated, and its down regulation by siRNA rendered neural progenitor cells more vulnerable to apoptosis. NRBP2 has no previously assigned function and our studies suggest a role for NRBP2 in neural progenitor cell survival.
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| 8. |
- Malmstrom, Mikael, et al.
(författare)
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Waveguides in polycrystalline diamond for mid-IR sensing
- 2016
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Ingår i: Optical Materials Express. - 2159-3930 .- 2159-3930. ; 6:4, s. 1286-1295
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Tidskriftsartikel (refereegranskat)abstract
- 8 mm long channel waveguides were manufactured in polycrystalline diamond with inductively coupled plasma etching and characterized in terms of mode-profile and propagation loss in the 1.5 - 3.4 mu m spectral region. As proof of principle, the waveguides were evaluated in an evanescent field sensing setup targeting the CH absorption peak of isopropanol at similar to 3.4 mu m, showing good agreement with numerical finite element simulations. (C) 2016 Optical Society of America
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| 9. |
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| 10. |
- Malmström, Mikael, 1982-, et al.
(författare)
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Diamond waveguides for mid-IR sensing
- 2014
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Ingår i: Optics & Photonics in Sweden. ; , s. 1-1
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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