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A combined experimental and numerical approach to the investigation of the influence of geometry on residual stresses in structural glass
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An experimentally validated contour method/eigenstrains hybrid model to incorporate residual stresses in glass structural designs
No full textContour method-based finite element (FE) models together with knowledge of the surface deformation resulted from the stress relaxation along a newly cut plane were used to construct the residual stresses in commercially available float glass. The results show that the residual stress depth profile of float glass is parabolic. The constructed residual stress profiles, validated to some extent against results of scattered-light-polariscope (SCALP) experiments, were then used to establish the misfit strains (i.e. eigenstrains) existed in the original glass specimens. It is shown that, despite the modelling uncertainty of the contour method and the limitations associated with the SCALP measurements, the eigenstrain depth profile in a given float glass specimen can be determined to an acceptable accuracy. The paper shows that once the underlying eigenstrain distribution in a given thickness of glass has been determined, the complete residual stress distribution can simply be determined by incorporating the eigenstrain profile as a misfit strain in an appropriate FE model. It is also shown that the hybrid contour/eigenstrain model enables modelling the residual stress around stress concentration features such as holes and/or stress evolution during subsequent applied loadings, by simply using the knowledge of eigenstrains
Assessment of stresses in float and tempered glass using Eigenstrains
No full textResidual stress data determined using the contour method has been used to determine the misfit-strains (i.e., eigenstrains) existent in float glass. Although the uncertainty associated with the results of the contour method analysis may be high the results agree with the residual stress profiles measured using scattered-light-polariscope experiments. The relationship between the eigenstrains and the thickness of glass has been investigated and the results have been validated using scattered-light-polariscopic experiments. The paper shows that the eigenstrain distribution depends on the differential cooling takes place during the manufacturing process. Once the underlying eigenstrain distribution in a given float glass product has been determined this can be used to devise the eigenstrain distribution in tempered glass. It is also shown that eigenstrain analysis can be implemented in finite element models to predict structural response of glass structures thereby to ensure efficient, safe and reliable designs
Transcriptomic responses to biotic stresses in Malus x domestica: A meta-analysis study
Full text linkRNA-Seq analysis is a strong tool to gain insight into the molecular responses to biotic stresses in plants. The objective of this work is to identify specific and common molecular responses between different transcriptomic data related to fungi, virus and bacteria attacks in Malus x domestica. We analyzed seven transcriptomic datasets in Malus x domestica divided in responses to fungal pathogens, virus (Apple Stem Grooving Virus) and bacteria (Erwinia amylovora). Data were dissected using an integrated approach of pathway- and gene- set enrichment analysis, Mapman visualization tool, gene ontology analysis and inferred protein-protein interaction network. Our meta-analysis revealed that the bacterial infection enhanced specifically genes involved in sugar alcohol metabolism. Brassinosteroids were upregulated by fungal pathogens while ethylene was highly affected by Erwinia amylovora. Gibberellins and jasmonates were strongly repressed by fungal and viral infections. The protein-protein interaction network highlighted the role of WRKYs in responses to the studied pathogens. In summary, our meta-analysis provides a better understanding of the Malus X domestica transcriptome responses to different biotic stress conditions; we anticipate that these insights will assist in the development of genetic resistance and acute therapeutic strategies. This work would be an example for next meta-analysis works aiming at identifying specific common molecular features linked with biotic stress responses in other specialty crops
Gaining Insight into Exclusive and Common Transcriptomic Features Linked with Biotic Stress Responses in Malus
Full text linkIdentifying key information in transcriptomic data is very important, especially when the “omic” study deals with plant responses to stresses in field conditions where a high number of variables and disturbing factors may affect the analysis. In this meta-analysis we collected 12 transcriptomic works in Malus in order to identify which key genes, proteins, gene categories are involved in general plant pathological conditions and those features linked with exclusive biotic stress responses. Those genes that are only related with molecular responses to pathogen attacks and those linked with other plant physiological processes were identified. A pipeline composed by pathway and gene set enrichment analysis, protein-protein interaction networks and gene visualization tools was employed. A total of 13,230 genes of the 12 studies were analyzed with functional data mining tools: 5,215 were upregulated, 8,015 were downregulated. Gene set enrichment analysis pointed out that photosynthesis was inhibited by Erwinia amylovora and fungal pathogens. Different hormonal crosstalk was linked with responses to different pathogens. Gibberellin-related pathways, ABA-related were mostly repressed by fungal pathogens. Relating to transcription factors, genes encoding MYBs and WRKY2 were downregulated by fungal pathogens and 12 WRKYs were commonly regulated by different biotic stresses The protein-protein interaction analysis discovered the presence of several proteins affected by more than one biotic stress including a WRKY40 and some highly interactive proteins such as heat shock proteins. This study represents a first preliminary curated meta-analysis of apple transcriptomic responses to biotic stresses
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