12 research outputs found

    Management development: a literature review and implications for future research – Part I: Conceptualisations and Practices

    No full text
    Interest in management development is mushrooming. The number of articles which address different aspects of it are likewise increasing apace. This has heightened the need for a broad-based review which will pull the material together, give shape to it, evaluate it and draw out its implications. In this, the first of a two-part article, this task is commenced

    Compaction Behavior and Mechanical Properties of Uniaxially Pressed Bi-W Composites

    Get PDF
    Powder metallurgy is a useful route to forming particulate composite materials; however, the densification of hard and soft powder mixtures is usually inhibited by the more refractory phase. The Bi-W powder compacts were uniaxially pressed at room temperature and the compaction behavior and mechanical properties were evaluated. Pressing was performed in incremental steps from ~1 to 540 MPa. After each step, the pressure was relieved and the thickness and sound-wave transit time were measured in situ (in the die), in order to determine the density and sound-wave velocity in the compact. The data show that the unreinforced Bi powder compacts to ~98 pct density at 540 MPa. The W reinforcement inhibits the densification process, resulting in increased levels of residual porosity. The compaction behavior was evaluated using a modified Heckel equation, while the porosity dependence of the ultrasonically determined elastic modulus was described by a site percolation approach. Postcompaction sound-wave velocity and Vicker’s hardness measurements show <5 pct anisotropy between the axial (pressing) and radial directions. The mechanical characterization illustrates the competing effects of the W reinforcement and the associated residual porosity

    Diurnal transcript profiling of the diatom Seminavis robusta

    No full text
    Coastal regions contribute an estimated 20% of annual gross primary production in the oceans, despite occupying only 0.03% of their surface area. Diatoms frequently dominate coastal sediments, where they experience large variations in light regime resulting from the interplay of diurnal and tidal cycles. Here, we report on an extensive diurnal transcript profiling experiment of the motile benthic diatom Seminavis robusta. Nearly 90% (23 328) of expressed protein-coding genes and 66.9% (1124) of expressed long intergenic non-coding RNAs showed significant expression oscillations and are predominantly phasing at night with a periodicity of 24 h. Phylostratigraphic analysis found that rhythmic genes are enriched in highly conserved genes, while diatom-specific genes are predominantly associated with midnight expression. Integration of genetic and physiological cell cycle markers with silica depletion data revealed potential new silica cell wall-associated gene families specific to diatoms. Additionally, we observed 1752 genes with a remarkable semidiurnal (12-h) periodicity, while the expansion of putative circadian transcription factors may reflect adaptations to cope with highly unpredictable external conditions. Taken together, our results provide new insights into the adaptations of diatoms to the benthic environment and serve as a valuable resource for the study of diurnal regulation in photosynthetic eukaryotes
    corecore