O 1s excitation and ionization processes in the CO2 molecule studied via detection of low-energy fluorescence emission

Oxygen 1s excitation and ionization processes in the CO2 molecule have been studied with dispersed and non-dispersed fluorescence spectroscopy as well as with the vacuum ultraviolet (VUV) photon?photoion coincidence technique. The intensity of the neutral O emission line at 845 nm shows particular sensitivity to core-to-Rydberg excitations and core?valence double excitations, while shape resonances are suppressed. In contrast, the partial fluorescence yield in the wavelength window 300?650 nm and the excitation functions of selected O+ and C+ emission lines in the wavelength range 400?500 nm display all of the absorption features. The relative intensity of ionic emission in the visible range increases towards higher photon energies, which is attributed to O 1s shake-off photoionization. VUV photon?photoion coincidence spectra reveal major contributions from the C+ and O+ ions and a minor contribution from C2+. No conclusive changes in the intensity ratios among the different ions are observed above the O 1s threshold. The line shape of the VUV?O+ coincidence peak in the mass spectrum carries some information on the initial core excitatio

The Role of Auditing in the Management of Corporate Fraud

Purpose This chapter adopts Porter’s ‘audit trinity’ approach comprising internal audit, external audit and audit committee to discuss the role auditing can play in the management of corporate fraud. Design/methodology/approach The chapter maps the historical background of and the developments in external audit as an assurance service, the internal audit function and the audit committee. Based on this, it explains the nature, types and possible causes of corporate fraud within the context of business risk with a view to establishing how auditing can help in managing such frauds. Findings The chapter highlights the relationships that should exist between the three audit types in order to support a sound internal control system as a tool for preventing and detecting corporate fraud. Research limitations/implications The chapter identifies cost, opportunity, connivance and managerial override as factors that could limit the ability of auditing to manage corporate fraud. It also suggests ways of addressing these limitations. Practical implications As the current upward trend in IT adoption for corporate operations continue to open new sets of corporate fraud windows, this chapter examines how an entity’s internal controls can be used to prevent and detect these growing fraud schemes. Originality/value The chapter’s unique strength is its adoption of a holistic approach to auditing to suggest ways of managing corporate fraud – a novelty in the corporate fraud literature. It is hoped that future research in the area will bring empirical insights to the issues raised and perspectives covered in the chapter