11,787,917 research outputs found
Adsorption and photo-oxidation of 3,4-dihydroxy-cinnamic acid on TiO2 films
Get PDFThe photo-oxidation of 3,4-dihydroxy-cinnamic acid (DHCA) is investigated on TiO2 films prepared from commercial Degussa P-25 (FP25 films) and from colloidal TiO2 prepared by the sol-gel method (FSG films). Photo-oxidation rates have been found to be inversely correlated to the amount of adsorbed species. The extent of adsorption increases as the solution pH increases from 1 to 4 and is more pronounced in the case of FP25 samples for which the amount of adsorbed species is 2.7 x 10-10 mol cm-2 i.e. about threefold higher than for the FSG case. Analysis of DHCA adsorption on TiO2 suspensions provided information complementary to that collected on films. Diffuse reflectance UV-visible and FTIR spectra of adsorbed DHCA are conspicuously different for the two types of films
Accounting, actorhood and actors: A comment on: Casting call: The expanding nature of actorhood in U.S. Firms, 1960–2010 by Patricia Bromley and Amanda Sharkey
Get PDFThe paper by Bromley & Sharkey (2017) brings to the fore the notion of actorhood as developed in the work of John Meyer and his colleagues, which has been only tangentially mobilised within accounting scholarship. This commentary proposes some reasons for this limited mobilisation and discusses the intellectual value of the concept of actorhood for accounting research and new institutionalism in organisation studies more broadly. In particular, it offers some reflections on how actorhood in new institutionalism, action in actor-network theory and subjectification in the Foucauldian tradition may be placed in a productive dialogue
Performance measurement in global governance:Ranking and the politics of variability
Get PDFThe past thirty years have witnessed the spread of rankings, ratings and league tables as governance technologies which aim to regulate the provision of public goods by means of market pressures. This paper examines the process of company analysis underlying the production of a ranking known as the Access to Medicine Index. We conceptualize the Index as a “regulatory ranking” with the explicit mission of addressing a perceived regulatory gap and market failure: the lack of access to medicine in the Global South. The Index, which ranks the world's largest pharmaceutical companies with regards to their access to medicine policies and practices, aspires to help address the problem of access to medicine through stakeholder consultation, transparency and competition. This study unbundles the epistemic work underlying the performance measurement process leading to the creation of the Index. We trace how the goal of stakeholder consensus, the need to project objectivity and the aspiration to govern through competition shape analysts' epistemic work. We discuss how through notions such as “the good distribution” and “aspirational indicators”, performance measurement and ranking become entangled in a “politics of variability” whereby company data need to be variably interpreted in order to optimise the possibilities of intervening in companies through competitive pressures, while at the same time complying with the imperatives to remain in the space of perceived stakeholder consensus and to provide a faithful representation of companies performance to inform public debates. We reflect on the challenges posed by these analysis processes for the regulatory aspirations of the ranking.</p
Commensuration and styles of reasoning:Venice, cost-benefit, and the defence of place
Get PDFThis paper discusses some preconditions for "making things the same" by means of quantification and economic calculation. It examines a controversial cost-benefit analysis, conducted as part of the environmental appraisal of a large public sector project in Italy: the long-debated scheme for flood protection in Venice. By tracing the different "styles of calculation" that characterised the economic and environmental appraisal of the project, the paper analyses the inter-relationship between economic representations of the urban and natural environment, its political symbolism, and various attempts to intervene upon it. It follows how the objectivity of numbers is debated, stabilised or disrupted, as differing appeals to realism and accuracy are advanced in the context of different modes of intervention and practical aims. The paper shows that the "commensuration" and "standardisation" that numbers can bring about rest on how the object of calculation as well as, crucially, its subject are represented and conceived.</p
The Institutional Drama of Conservation
No full textThis study uses the case of the "Safeguard" of Venice-in which there is a continuous tension between the aspiration to "modernize" and to "restore" the city, its economy, and its surrounding lagoon environment-to highlight the symbolic function of heritage in shaping government policies. It demonstrates how the effectiveness of the national government as a guarantor of the Safeguard of Venice was questioned both in the name of tradition and of modernization and discusses the unintended consequences of this continuous dramatization of the state and its policies for the city. The study points at some challenges posed by heritage conservation on state identity at a time of increasing transnationalization of heritage policies and private sector involvement. © 2012 M.E. Sharpe, Inc. All rights reserved
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
Semantic Styles in the British Daily Press: a corpus study
Get PDFThis study aims at establishing whether the lexico-grammatical and semantic differences between British popular and quality newspapers can be connected to the concepts of coding orientations (Bernstein 1973, 1975, 1977, 1982, 1990) and semantic styles (Hasan 1973, 1984, 1986, 1989). For this purpose, a corpus of 83 British newspaper articles has been collected. The articles are on the same topic and were published on two consecutive days, but they belong to different genres, in particular news report and editorial comment. The corpus has been divided into different sub-corpora on the basis of the genre the articles belong to, and on the basis of the kind of newspaper they are taken from (quality or popular). The corpus has been tagged with tagging systems based on Halliday’s (1994) systemic functional grammar, and the frequencies of the various tags have been counted using the Wordsmith Tools program. The data have then been elaborated using a non-parametric statistical test, the Mann-Whitney test, in order to establish which lexico-grammatical and semantic categories indicate statistically significant differences between popular and quality newspapers.
The data thus obtained lie at the basis of the discussion of the main differences between quality and popular newspaper articles. These differences have been interpreted in relation to Basil Bernstein’s and Ruqaiya Hasan’s studies on the different values which inform the language used by different social groups, focussing on how journalists adapt their language to the presumed values of the social groups their newspapers are addressed to.
The first chapter of the dissertation explains the concepts of coding orientation and semantic style and the main aspects of Halliday’s systemic functional model, within which these concepts have been elaborated and / or developed. In the same chapter an overview is given of the main differences between quality and popular newspapers which have been discussed so far in the literature.
Chapter two illustrates the corpus which has been analysed, the sub-corpora it has been divided into, and the rationale behind the choice of the articles and their categoisation.
Chapter three describes the grammatical categories the corpus has been tagged for, the 300 different tags which have been adopted, and the aims of the various analyses. It offers short illustrations of the theoretical aspects which lie at the basis of the different systems the corpus has been analysed for, i.e., Transitivity, Ergativity, Clause Complexing, Conjunctive Relations, Participant Identification, Mood and Modality, and Appraisal.
Chapter four briefly illustrates the statistical test which has been applied to the data and it shows all the statistically significant outputs, i.e., those for which the error chance was 5% or less. It also shows the outputs of the statistical test for some categories which, contrary to expectation, were not statistically significant.
Chapter five presents the discussion and interpretation of the results on the basis of the concept of semantic style.
Chapter six offers some final reflections on the concept of ideology and its place in the systemic functional linguistic theory. In particular, in this chapter it is claimed that this concept lies at the very basis of the models of language and context which systemic theory has developed
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 TiNO. 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 NO x 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. © 2012 Elsevier B.V. All rights reserved
N-TiO2 Photocatalysts highly active under visible irradiation for NOX abatement and 2-propanol oxidation
Get PDFN-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
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