177,007 research outputs found
Auditor judgment in the Fourth Industrial Revolution
No full textDiscourse proclaiming the advent of a fourth industrial revolution predicts significant disruption to various work domains in the near future. Auditing is one of the domains where bold claims about the potential of technology are being made, with technology expected to augment auditors' judgments and, in time, possibly automate them. Drawing on 44 in-depth interviews with auditors, regulators, and emergent artificial intelligence software providers, we question the prevailing narrative around technological change in auditing which suggests that ostensibly simple, low-level technical tasks are areas where little judgment is at play and thus are ripe for automation. We show that significant elements of deliberation, sensemaking, and reflexivity, arguably critical for the socialization of early career auditors into the profession, may be lost when automating areas of work perceived as low value, leading us to question what it means to apply judgment in auditing. Conversely, higher-level aspects of the audit process may be assisted by technology and augmented in different ways, yet new technological structures generate new areas of indeterminacy that pose new and yet unresolved demands on auditors' judgment. Overall, the paper shows how auditor habits are changing and highlights the risks posed by new technologies to the acquisition of practical knowledge by auditors
Photo-electro catalytic oxidation of aromatic alcohols on visible light-absorbing nitrogen-doped TiO2
No full textVisible light illumination of nitrogen-doped TiO(2) brings about the selective oxidation of benzyl and cinnamyl alcohol to the corresponding aldehydes. The photocatalyst was prepared by a sol-gel method and characterised mainly by XRD, UV-vis diffuse reflectance and Raman spectroscopy. The conditions limiting the observation of visible light photoactivity are the use of dry nitriles as nonaqueous solvents and aromatic alcohols as the substrates. No visible light oxidation takes place in an aqueous medium. The efficiency of benzyl and cinnamyl alcohol photo-oxidation in nitrile solvents follows the order: CH(3)CN > CH(3)CH(2)CN > CH(3)(CH(2))(2)CN. Conversely, since alcohol photo-oxidation occurs with 100% selectivity on electrodes in O(2) saturated solutions at potentials close to Eft, or under open-circuit conditions, suspensions of the photocatalyst can be advantageously employed. The process involves a relatively weak adsorption of the alcohol substrates which, however, do not readily capture the photogenerated holes. On the basis of the electrochemical and photoluminescence data, it appears that the solvent (e.g. acetonitrile), in addition to O(2) has an active role in the reaction mechanism. (C) 2010 Elsevier Ltd. All rights reserved
Photocatalytic formation of a carbamate through ethanol assisted carbonylation of p-nitrotoluene
No full textThe nitroarene p-nitrotoluene is converted with a selectivity higher than 85% to the corresponding carbamate at room temperature and atmospheric pressure, using photoexcited particles of TiO 2 as catalyst and EtOH as carbonylating species
N-TiO2 Photocatalysts highly active under visible irradiation for NOX abatement and 2-propanol oxidation
No full textN-doped TiO2 powders were prepared by two different sol–gel methods. Samples were characterised
by X-ray diffraction (XRD), BET specific surface area measurements (SSA), scanning electron microscopy
(SEM), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and Electron Paramagnetic
Resonance (EPR). XPS measurements revealed a signal at 400 eV assignable to nitrogen in the
form of Ti N O. EPR signals are attributed to molecular NO trapped with cavities/defects possibly interacting
with oxygen vacancies. The photocatalytic activity under UV and visible light was determined
following the abatement of NOx and the photodegradation of 2-propanol in gas–solid systems. N-doped
TiO2 showed a higher activity compared with the pristine commercial and home prepared samples
under visible light irradiation. A good photoactivity in the abatement of both NOx and 2-propanol is
also observed for mechanical dispersions of N-TiO2 in CaCO3 serving as a model in view of perspective
application in photocatalytically active construction and architectural materials
Preparation, Characterisation, and Photocatalytic Behaviour of Co-TiO2 with Visible Light Response
No full textThe preparation of cobalt-modified TiO2 (Co-TiO2) was carried out by the incipient impregnation method starting from commercial TiO2 (Degussa, P-25) and cobalt acetate. XPS data show that cobalt is incorporated as divalent ion, and it is likely present within few subsurface layers. No appreciable change in structural-morphologic properties, such as surface area and anatase/rutile phase ratio, was observed. Conversely, Co addition brings about conspicuous changes in the point of zero charge and in surface polarity. Diffuse reflectance spectra feature a red shift in light absorption that is dependent on the amount of cobalt. The influence of cobalt addition on the performance of TiO2 as a photocatalyst in the degradation of 4-chlorophenol and Bisphenol A is investigated. The results show that the modified oxide presents a higher photoactivity both for illumination with UV-visible (λ>360 nm) and visible light (λ>420 nm; λ>450 nm), and that this enhancement depends on the amount of the added species and on the final thermal treatment in the preparation step. We also show that Co-TiO2 is a more active catalyst than pure TiO2 for the reduction of O2 in the dark, which is an important reaction in the overall photocatalytic processes
Preparation and photoactivity of nanocrystalline TiO2 powders obtained by thermohydrolysis of TiOSO4
No full textNanocrystalline TiO2 photocatalysts were synthesized
in mild conditions by thermohydrolysis of TiOSO4
in water at 100 C and post-calcination treatment at various
temperatures. The TiO2 powders were characterized by
X-ray diffraction, X-ray photoelectron spectroscopy, specific
surface area determinations, scanning electron
microscopy and electron paramagnetic resonance measurements.
The photoactivity of the samples was tested
employing the photodegradation of 4-nitrophenol in
liquid–solid regimen and the photooxidation of gaseous
2-propanol. The best results were obtained with the powder
calcined at 600 C for 10 h. Surprisingly, the not calcined
sample was the most active for the abatement of NOx under
irradiation
Photo-electro-chemical properties of TiO2 mediated by the enzyme glucose oxidase
No full textElectrochemical measurements show that the enzyme Glucose oxidase (GO) is adsorbed on the surface of TiO2 without apparently changing the flat band potential of the semiconductor, indicating that it does not cause a change of the energy of conduction band electrons. On the other hand, it is observed that GO markedly increases the efficiency of the two electron reduction of O2 to H2O2 which is accumulated in the solution phase. ESR spin trapping investigations indicate that GO favors the formation of OH . radicals, due to either the inhibition of charge recombination processes or to H2O2 reduction by conduction band electrons. Accordingly, photo-oxidation of different alcohols to the corresponding radical species is also enhanced in the presence of GO. The photo-oxidation of 1,2-propandiol on TiO2/GO is regioselective in that i) partial oxidation to hydroxyacetone is observed and ii) no mineralization (full combustion to CO2) of the substrate occurs. These facts are of particular interest in the field of studies concerning the design of new photocatalytic systems with enhanced activity and controllable oxidative power
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Photocatalytic degradation activity of titanium dioxide sol-gel coatings on stainless steel wire meshes
No full textStainless steel wire meshes have been functionalised with multiple titanium dioxide (TiO2) coatings
deposited by the sol–gel technique, using titanium isopropoxide as precursor and titanium dioxide
nanopowders dispersed in the colloidal solution. After the thermal conversion of the amorphous fraction
of the coating into anatase, the functionalised stainless steel wire meshes were tested for the UV
photodegradation of aqueous solutions of methylene blue, solid stearic acid and nitrogen oxides in air.
The addition of TiO2 nanopowders in the colloidal deposition solution enhanced the photocatalytic performance
of the deposited TiO2 layers in all the tested conditions. Moreover, increasing the number of
coatings (from 1 to 4) improves the photocatalytic efficiency.
The catalyst did not show reduced photoreactivity after four repeated cycles in water decontamination
from methylene blue, and after up to 10 repeated cycles in nitrogen oxides photodegradation. Complete
regeneration of the catalyst could be achieved by rinsing it with warm deionised water and was observed
in the case of experiments for NOx abatement
Photocatalytic Properties of Nanostructured TiO2 Powders Obtained by Thermohydrolysis of TiOSO4
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