137 research outputs found

    Microstructure-based computational simulation and experimental measurement of stresses in spheroidized steels

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    金沢大学大学院自然科学研究科Carbon steel is the most popular engineering material, usually consisted of ferrite and cementite phases. Internal stress state of the steel under thermal or mechanical loading is strongly affected by the amount and morphology in the cementite phase. With this aim, a computational model which applies the finite element method at the microscale was used in present study. Effects of volume fraction and particle size of the spheriodal cementite on the internal stress states in carbon steels under the mechanical and thermal loadings are investigated. To verify the reliability of the computational simulations, the residual stresses in the constituent phases are measured by means of X-ray stress diffraction technique. The computational simulations fit well with the experimental data, and the microstructure-based model is validated

    Scratch test of TiCN thin films with different preferred orientation

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    The purpose of this study is to examine the effect of crystallite preferred orientation on the mechanical strength of TiCN thin films in highly compressive residual stress. TiCN thin films were deposited by PVD on JIS-SKH55 (AISI M35) steel. The applied substrate bias voltages were set for -50, -80, -100,-120 and -150V. Subsequently, residual stress and crystalline preferred orientation of these specimens were investigated by X-ray diffraction methodology. The crystalline preferred orientation in thin films was evaluated by the ODF calculated from pole figures. On the other hand, dynamic hardness test (DH) and scratch test were executed to evaluate the mechanical strength of thin films. In our study, it was observed that negative bias voltages had an effect on the preferred orientation. The orientation density at -120 V was the highest of all specimens. In addition, the value of scratch section area at -120V was the largest of all specimens. As a conclusion, the relation between the scratch area and the negative bias voltages corresponded to the relation between the preferred orientation and the bias voltages

    CDK19-related disorder results from both loss-of-function and gain-of-function de novo missense variants

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    Purpose To expand the recent description of a new neurodevelopmental syndrome related to alterations in CDK19. Methods Individuals were identified through international collaboration. Functional studies included autophosphorylation assays for CDK19 Gly28Arg and Tyr32His variants and in vivo zebrafish assays of the CDK19(G28R) and CDK19(Y32H). Results We describe 11 unrelated individuals (age range: 9 months to 14 years) with de novo missense variants mapped to the kinase domain of CDK19, including two recurrent changes at residues Tyr32 and Gly28. In vitro autophosphorylation and substrate phosphorylation assays revealed that kinase activity of protein was lower for p.Gly28Arg and higher for p.Tyr32His substitutions compared with that of the wild-type protein. Injection of CDK19 messenger RNA (mRNA) with either the Tyr32His or the Gly28Arg variants using in vivo zebrafish model significantly increased fraction of embryos with morphological abnormalities. Overall, the phenotype of the now 14 individuals with CDK19-related disorder includes universal developmental delay and facial dysmorphism, hypotonia (79%), seizures (64%), ophthalmologic anomalies (64%), and autism/autistic traits (56%). Conclusion CDK19 de novo missense variants are responsible for a novel neurodevelopmental disorder. Both kinase assay and zebrafish experiments showed that the pathogenetic mechanism may be more diverse than previously thought.Peer reviewe
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