A new technique for the sp2^2/sp3^3 characterisation of carbon materials

We present a technique to determine the sp$^3$/sp$^2$ ratio of carbon materials which is based on the electron energy-loss spectroscopy and which uses the theoretical spectrum of graphite obtained from ab initio electronic structure calculations. The method relies on the separation of the $\pi^*$ and $\sigma^*$ components of the carbon K-edge of graphite. This $\pi^*$ spectrum is adopted and assumed to be transferable to other carbon systems given an appropriate parametrisation of the broadening. The method is applied on a series of Monte-Carlo generated amorphous carbon structures and is shown to be stable over a wide range of the energy windows for which spectral integration is performed. The results are found to be in good agreement with the sp$^3$ fraction obtained from a microscopic scheme which uses the $\pi-$orbital axis vector (POAV1) analysis. The technique was also applied on a series of experimental spectra of amorphous carbon and was found to be in good agreement with the results obtained from a functional fitting approach.Comment: 5 pages, 4 figures, two tables revtex4, Submitted for publication to Phys. Rev. Let

Retention and intentions of professional accountants

This paper enhances understanding of factors underlying professional accountants’ high turnover rates. Various researchers, institutions and government bodies have identified accountants’ retention is of concern. However, traditional explanations, such as job satisfaction and organizational commitment, do not sufficiently account for the turnover rates observed in the accounting profession. A New Zealand (NZ) sample of professional accountants enabled us to identify a range of factor. Intentions to stay were very low, 50% of accountants expected to leave their current employer within 3 years of the survey date. Satisfaction with two core job characteristics, feedback and skill variety, in addition to work life balance (WLB) accounted for 65% of the variance of overall job satisfaction. WLB, or at least a lack of access to flexible work arrangements was strongly indicated as the primary consideration when choosing to remain with the present employer

Note sur le dessalement de canaux maritimes

Séance du 1er août 1951info:eu-repo/semantics/publishe