| 427391. |
- Kron, Johannes, et al.
(författare)
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Low-Delay Joint Source-Channel Mappings for the Gaussian MAC
- 2014
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Ingår i: IEEE Communications Letters. - 1089-7798 .- 1558-2558. ; 18:2, s. 249-252
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Tidskriftsartikel (refereegranskat)abstract
- The bivariate Gaussian multiterminal source coding problem with transmission over the Gaussian multiple-access channel is studied. We propose the use of low-delay joint source-channel mappings and show how performance saturation, which is unavoidable with linear transmission, can be overcome by optimizing the mappings. The optimized mappings are in general nonlinear and perform a combination of hard and soft decision signaling for the error-resilient transmission of analog data.
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| 427392. |
- Kron, J., et al.
(författare)
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Measurements and modelling of air gap formation in aluminium based alloys
- 2005
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Ingår i: International Journal of Cast Metals Research. - : Maney Publishing. - 1364-0461 .- 1743-1336. ; 18:1, s. 29-40
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Tidskriftsartikel (refereegranskat)abstract
- The formation of an air gap has been experimentally studied during solidification of several aluminium based alloys. Air gap widths and temperature distribution have been measured during solidification in a cylindrical mould. The effect of grain refinement on heat transfer and air gap formation has been studied. Mathematical modelling has been performed to increase the understanding of the solidification process and air gap formation. A model was developed for description of air gap formation in alloys solidifying with varying solidification intervals. The model includes the effect of formation and condensation of lattice defects on the solidification process and air gap formation. The calculated shrinkage using this model shows good agreement with the experimental data.
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| 427393. |
- Kron, J., et al.
(författare)
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Measurements and modelling of air gap formation in Cu-based alloys
- 2005
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Ingår i: International Journal of Cast Metals Research. - : Maney Publishing. - 1364-0461 .- 1743-1336. ; 18:1, s. 21-28
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Tidskriftsartikel (refereegranskat)abstract
- The formation of an air gap has been experimentally studied during solidification of pure Cu, Cu-Te and Cu-6%Sn in a cylindrical mould. The displacements of the casting and the mould causing an air gap have been measured during solidification and cooling of the casting. The temperature distribution was measured simultaneously. Mathematical modelling has been performed to increase the understanding of the solidification process and the shrinkage of the casting leading to air gap formation. A model, which has been tested in earlier work showing good results for aluminium based alloys, has been applied here to describe air gap formation during solidification of copper based alloys. The model includes the effect of the formation and condensation of vacancies on the solidification process as well as on the material shrinkage resulting in air gap formation. The results from the modelling show a reasonable agreement with the experimental measurements.
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| 427394. |
- Kron, Jenny, et al.
(författare)
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Modelling of air gap formation in solidification processing
- 2005
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Ingår i: Transactions of the Indian Institute of Metals. - 0019-493X. ; 58:4, s. 531-538
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Tidskriftsartikel (refereegranskat)abstract
- Different models are used today to model air gap formation during a solidification process. In this work air gap modelling is discussed with reference to experimental work with air gap measurements during casting. Thermal and thermomechanical modelling were done with thermal boundary conditions found experimentally. The measured displacements of the mould and the solidifying metal were used in order to check the validity of the simulation results and compare it with reality. The description of the thermal shrinkage and its connection to air gap formation is especially discussed. Al- and Fe-based alloys investigated elsewhere have been used in this work.
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| 427395. |
- Kron, Linus, 1996, et al.
(författare)
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A comparative study of the cell wall level delignification behaviour of four Nordic hardwoods during kraft pulping
- 2024
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Ingår i: Holzforschung. - 1437-434X .- 0018-3830. ; 78:8, s. 434-445
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Tidskriftsartikel (refereegranskat)abstract
- Wood is a heterogeneous material with significant variation among species. This inherent complexity poses a challenge to the continuous expansion of our understanding of the kraft process; yet previous pulping research has mainly been limited to a few species. This study investigates variations among some less studied species and their cell wall level delignification behaviour during kraft pulping. Ground wood of birch, beech, aspen, and alder were pulped at near-constant composition and temperature conditions. Minor, yet significant, differences in the rates of their delignification were observed: aspen had a pronounced fast rate during the initial stage, whereas alder delignified more slowly relative to its high initial lignin content. The dissolution of xylan was substantially faster for birch. In contrast, no substantial differences were detected between the species in the molecular weight and structure of the dissolved wood components, suggesting that the different delignification behaviours stem from variations in the residual phase. The molecular weight distribution of dissolved lignin was uniform during the initial stage of pulping, which is indicative of rapid and extensive fragmentation. Subsequently, the weight increased continuously for the remainder of the process, suggesting that the mass transfer within the cell wall influenced the overall delignification kinetics.
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| 427396. |
- Kron, Linus, 1996, et al.
(författare)
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Kraft cooking of birch wood chips: Differences between the dissolved organic material in pore and bulk liquor
- 2023
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Ingår i: Holzforschung. - 1437-434X .- 0018-3830. ; 77:8, s. 598-609
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Tidskriftsartikel (refereegranskat)abstract
- The delignification of birch chips during kraft pulping was investigated, targeting both the impregnation and cooking steps. Wood chips were impregnated using white liquor, white liquor + NaCl, water or NaCl aqueous solution. Then, the chips were cooked in batch autoclaves applying the same constant composition cooking conditions for all samples. Pulp and two fractions of black liquor (bulk liquor and centrifuged liquor representing the liquor inside the wood chips and fibers) were collected after different pulping times and analyzed for lignin and carbohydrate content. The dissolved wood components were precipitated from selected samples and characterized with respect to composition, molecular weight distribution and structural motifs. Cooking chemicals in the impregnation liquors led to faster delignification and xylan removal during cooking. Higher contents of lignin and xylan were measured in the lumen than in the bulk. The concentration profiles also showed accumulation of dissolved material in the lumen over time, suggesting significant mass transport limitation from lumen to bulk. Further analysis revealed higher fragmentation/degradation of dissolved material with increasing pulping time and in the bulk when compared to the lumen liquor, as demonstrated by the lower molecular weights and the changes in chemical shifts in the NMR spectra.
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| 427397. |
- Kron, Nathalie, et al.
(författare)
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The demand-what-you-want strategy to service recovery : Achieving high customer satisfaction with low service failure compensation using anchoring and precision effects
- 2023
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Ingår i: Journal of service theory and practice. - : Emerald. - 2055-6225 .- 2055-6233. ; 33:7, s. 73-93
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Tidskriftsartikel (refereegranskat)abstract
- PurposePrevious research suggests that the compensation offered to customers after a service failure has to be substantial to make customer satisfaction surpass that of an error-free service. However, with the right service recovery strategy, it might be possible to reduce compensation size while maintaining happy customers. The aim of the current study is to test whether an anchoring technique can be used to achieve this goal.Design/methodology/approachAfter experiencing a service failure, participants were told that there is a standard size of the compensation for service failures. The size of this standard was different depending on condition. Thereafter, participants were asked how much they would demand to be satisfied with their customer experience.FindingsThe compensation demand was relatively high on average (1,000–1,400 SEK, ≈ $120). However, telling the participants that customers typically receive 200 SEK as compensation reduced their demand to about 800 SEK (Experiment 1)—an anchoring effect. Moreover, a precise anchoring point (a typical compensation of 247 SEK) generated a lower demand than rounded anchoring points, even when the rounded anchoring point was lower (200 SEK) than the precise counterpart (Experiment 2)—a precision effect.Implications/valueSetting a low compensation standard—yet allowing customers to actually receive compensations above the standard—can make customers more satisfied while also saving resources in demand-what-you-want service recovery situations, in particular when the compensation standard is a precise value.
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| 427398. |
- Krona, Annika, et al.
(författare)
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Developing cultured meat scaffolds of extruded vegetable-based proteins
- 2017
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Ingår i: Annual Transactions of the Nordic Rheology Society. ; 25, s. 311-
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Tidskriftsartikel (refereegranskat)abstract
- Muscle cells from animals can becultivated in cell culture medium, but to beused as a meat food product, they need asolid matrix to grow on that can alsocontribute to the texture. In this project wehave created promising fibrous growthsubstrates from extruded plant basedproteins that the cells are able to attach toand grow on. Cultured meat is still far froma commercial product, but may, in the longrun, give even tastier, healthier and moreenvironmentally friendly meat products.
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| 427399. |
- Krona, Annika, 1973, et al.
(författare)
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Oncostatin M signaling in human glioma cell lines.
- 2005
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Ingår i: Oncology reports. - 1021-335X .- 1791-2431. ; 13:5, s. 807-11
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Tidskriftsartikel (refereegranskat)abstract
- We have recently found that oncostatin M (OSM) is overexpressed in most human brain tumors. The effects of OSM are unclear with conflicting reports of growth stimulatory or inhibitory effects in various cell types. The aim of this study was to investigate the effects of OSM in 5 glioma cell lines and 7 short-term cultures of human gliomas and in normal cultured human astrocytes. None of the cell lines and short-term cultured tumor cells expressed OSM in vitro. OSM signals through a gp130 containing receptor complex over the JAK/STAT pathway. Immunofluorescence and RT-PCR analysis showed that the tumor cells express gp130 and the other receptor components, LIFRbeta and OSMRbeta. OSM treatment induced phosphorylation of STAT3 and STAT1 indicating presence of a functional JAK/STAT pathway. No OSM effect on proliferation was observed. OSM gave no protective effects against tumor necrosis factor-related apoptosis inducing ligand (TRAIL)-induced cytotoxicity.
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| 427400. |
- Krona, Cecilia, 1976, et al.
(författare)
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A novel 1p36.2 located gene, APITD1, with tumour-suppressive properties and a putative p53-binding domain, shows low expression in neuroblastoma tumours.
- 2004
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Ingår i: British journal of cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 91:6, s. 1119-30
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Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma is characterised by a lack of TP53 mutations and no other tumour suppressor gene consistently inactivated has yet been identified in this childhood cancer form. Characterisation of a new gene, denoted APITD1, in the neuroblastoma tumour suppressor candidate region in chromosome 1p36.22 reveals that APITD1 contains a predicted TFIID-31 domain, representing the TATA box-binding protein-associated factor, TAF(II)31, which is required for p53-mediated transcription activation. Two different transcripts of this gene were shown to be ubiquitously expressed, one of them with an elevated expression in foetal tissues. Primary neuroblastoma tumours of all different stages showed either very weak or no measurable APITD1 expression, contrary to the level of expression observed in neuroblastoma cell lines. A reduced pattern of expression was also observed in a set of various tumour types. APITD1 was functionally tested by adding APITD1 mRNA to neuroblastoma cells, leading to the cell growth to be reduced up to 90% compared to control cells, suggesting APITD1 to have a role in a cell death pathway. Furthermore, we determined the genomic organisation of APITD1. Automated genomic DNA sequencing of the coding region of the gene as well as the promoter sequence in 44 neuroblastoma tumours did not reveal any loss-of-function mutations, indicating that mutations in APITD1 is not a common abnormality of neuroblastoma tumours. We suggest that low expression of this gene might interfere with the ability for apoptosis through the p53 pathway.
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