5,379 research outputs found

    Identification of single-site gold catalysis in acetylene hydrochlorination

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    There remains considerable debate over the active form of gold under operating conditions of a recently validated gold catalyst for acetylene hydrochlorination. We have performed an in situ x-ray absorption fine structure study of gold/carbon (Au/C) catalysts under acetylene hydrochlorination reaction conditions and show that highly active catalysts comprise single-site cationic Au entities whose activity correlates with the ratio of Au(I):Au(III) present. We demonstrate that these Au/C catalysts are supported analogs of single-site homogeneous Au catalysts and propose a mechanism, supported by computational modeling, based on a redox couple of Au(I)-Au(III) species. View Full Tex

    The discomforting rise of ' public geographies': a 'public' conversation.

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    In this innovative and provocative intervention, the authors explore the burgeoning ‘public turn’ visible across the social sciences to espouse the need to radically challenge and reshape dominant and orthodox visions of ‘the academy’, academic life, and the role and purpose of the academic

    The tactical mimicry of social enterprise strategies: acting ‘as if’ in the everyday life of third sector organizations

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    Using England as a paradigmatic case of the „enterprising up ‟ of the third sector through social enterprise policies and programs, this article sheds light on resistance as enacted through dramaturgical identification with government strategies. Drawing from a longitudinal qualitative research study, which is interpreted via Michel de Certeau‟s theory of the everyday, we present the case study of Teak, a charitable regeneration company, to illustrate how its Chief Executive Liam „acted as ‟ a social entrepreneur in order to gain access to important resources. We establish „tactical mimicry ‟ as a sensitizing concept to suggest that third sector practitioners ‟ identification with the normative premises of „social enterprise ‟ is part of a parasitical prosaics geared toward appropriating public money. While tactical mimicry conforms to strategies only in order to exploit them, its ultimate aim is to increase potentials of collective agency outside the direct influence of power. The contribution we make is threefold: first, we extend the recent debate on productive resistance by highlighting how „playing the game ‟ without changing existing relations of power can nevertheless produce largely favorable outcomes. Second, we suggest that recognition of the productive potential of tactical mimicry requires methodologies which pay attention to the spatial and temporal dynamics of resistance. And third, we argue that explaining „social enterprise‟ without consideration of the non-discursive, mainly financial resources made available to those who identify with it, necessarily risks overlooking a crucial element of the dramaturgical dynamic of discourse

    Extensive Spectroscopy and Photometry of the Type IIP Supernova 2013ej

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    We present extensive optical (UBVRIUBVRI, grizg'r'i'z', and open CCD) and near-infrared (ZYJHZYJH) photometry for the very nearby Type IIP SN ~2013ej extending from +1 to +461 days after shock breakout, estimated to be MJD 56496.9±0.356496.9\pm0.3. Substantial time series ultraviolet and optical spectroscopy obtained from +8 to +135 days are also presented. Considering well-observed SNe IIP from the literature, we derive UBVRIJHKUBVRIJHK bolometric calibrations from UBVRIUBVRI and unfiltered measurements that potentially reach 2\% precision with a BVB-V color-dependent correction. We observe moderately strong Si II λ6355\lambda6355 as early as +8 days. The photospheric velocity (vphv_{\rm ph}) is determined by modeling the spectra in the vicinity of Fe II λ5169\lambda5169 whenever observed, and interpolating at photometric epochs based on a semianalytic method. This gives vph=4500±500v_{\rm ph} = 4500\pm500 km s1^{-1} at +50 days. We also observe spectral homogeneity of ultraviolet spectra at +10--12 days for SNe IIP, while variations are evident a week after explosion. Using the expanding photosphere method, from combined analysis of SN 2013ej and SN 2002ap, we estimate the distance to the host galaxy to be 9.00.6+0.49.0_{-0.6}^{+0.4} Mpc, consistent with distance estimates from other methods. Photometric and spectroscopic analysis during the plateau phase, which we estimated to be 94±794\pm7 days long, yields an explosion energy of 0.9±0.3×10510.9\pm0.3\times10^{51} ergs, a final pre-explosion progenitor mass of 15.2±4.215.2\pm4.2~M_\odot and a radius of 250±70250\pm70~R_\odot. We observe a broken exponential profile beyond +120 days, with a break point at +183±16183\pm16 days. Measurements beyond this break time yield a 56^{56}Ni mass of 0.013±0.0010.013\pm0.001~M_\odot.Comment: 29 pages, 23 figures, 15 tables, Published in The Astrophisical Journa

    The HST Key Project on the Extragalactic Distance Scale. XV. A Cepheid Distance to the Fornax Cluster and Its Implications

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    Using the Hubble Space Telescope (HST) 37 long-period Cepheid variables have been discovered in the Fornax Cluster spiral galaxy NGC 1365. The resulting V and I period-luminosity relations yield a true distance modulus of 31.35 +/- 0.07 mag, which corresponds to a distance of 18.6 +/- 0.6 Mpc. This measurement provides several routes for estimating the Hubble Constant. (1) Assuming this distance for the Fornax Cluster as a whole yields a local Hubble Constant of 70 +/-18_{random} [+/-7]_{systematic} km/s/Mpc. (2) Nine Cepheid-based distances to groups of galaxies out to and including the Fornax and Virgo clusters yield Ho = 73 (+/-16)_r [+/-7]_s km/s/Mpc. (3) Recalibrating the I-band Tully-Fisher relation using NGC 1365 and six nearby spiral galaxies, and applying it to 15 galaxy clusters out to 100 Mpc gives Ho = 76 (+/-3)_r [+/-8]_s km/s/Mpc. (4) Using a broad-based set of differential cluster distance moduli ranging from Fornax to Abell 2147 gives Ho = 72 (+/-)_r [+/-6]_s km/s/Mpc. And finally, (5) Assuming the NGC 1365 distance for the two additional Type Ia supernovae in Fornax and adding them to the SnIa calibration (correcting for light curve shape) gives Ho = 67 (+/-6)_r [+/-7]_s km/s/Mpc out to a distance in excess of 500 Mpc. All five of these Ho determinations agree to within their statistical errors. The resulting estimate of the Hubble Constant combining all these determinations is Ho = 72 (+/-5)_r [+/-12]_s km/s/Mpc.Comment: Accepted for publication in the Astrophysical Journal, Apr. 10 issue 28 pages, 3 tables, 12 figures (Correct figures and abstract

    Transnational reflections on transnational research projects on men, boys and gender relations

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    This article reflects on the research project, ‘Engaging South African and Finnish youth towards new traditions of non-violence, equality and social well-being’, funded by the Finnish and South African national research councils, in the context of wider debates on research, projects and transnational processes. The project is located within a broader analysis of research projects and projectization (the reduction of research to separate projects), and the increasing tendencies for research to be framed within and as projects, with their own specific temporal and organizational characteristics. This approach is developed further in terms of different understandings of research across borders: international, comparative, multinational and transnational. Special attention is given to differences between research projects that are in the Europe and the EU, and projects that are between the global North and the global South. The theoretical, political and practical challenges of the North-South research project are discussed

    A 'Performative' Social Movement: The Emergence of Collective Contentions within Collaborative Governance

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    The enmeshment of urban movements in networks of collaborative governance has been characterised as a process of co-option in which previously disruptive contentions are absorbed by regimes and reproduced in ways that do not threaten the stability of power relations. Applying a theoretical framework drawn from feminist philosopher Judith Butler this paper directs attention to the development of collective oppositional identities that remain embedded in conventional political processes. In a case study of the English tenants' movement, it investigates the potential of regulatory discourses that draw on market theories of performative voice to offer the collectivising narratives and belief in change that can generate the emotional identification of a social movement. The paper originates the concept of the ‘performative social movement’ to denote the contentious claims that continue to emerge from urban movements that otherwise appear quiescent

    Responding to class theft: Theoretical and empirical links to critical management studies

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    Redrafted submission for inclusion in Remarx Section of Rethinking MarxismThis paper suggests closer linkages between the fields of Postmodern Class Analysis (PCA) and Critical Management Studies (CMS)2 are possible. It argues that CMS might contribute to the empirical engagement with the over-determined relations between class and non-class processes in work organizations (this appears to have received relatively little attention in PCA) and that PCA's theoretical and conceptual commitments may provide one means for CMS to engage in class analysis. CMS's focus on power and symbolic relations has led to the relative neglect of exploitation and class, in surplus terms. Both fields share similar although not identical political and ethical commitments

    Provision of foot health services for people with rheumatoid arthritis in New South Wales: a web-based survey of local podiatrists

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    Background: It is unclear if podiatric foot care for people with rheumatoid arthritis (RA) in New South Wales (NSW) meets current clinical recommendations. The objective of this study was to survey podiatrists' perceptions of the nature of podiatric foot care provision for people who have RA in NSW.Methods: An anonymous, cross-sectional survey with a web-based questionnaire was conducted. The survey questionnaire was developed according to clinical experience and current foot care recommendations. State registered podiatrists practising in the state of NSW were invited to participate. The survey link was distributed initially via email to members of the Australian Podiatry Association (NSW), and distributed further through snowballing techniques using professional networks. Data was analysed to assess significant associations between adherence to clinical practice guidelines, and private/public podiatry practices.Results: 86 podiatrists participated in the survey (78% from private practice, 22% from public practice). Respondents largely did not adhere to formal guidelines to manage their patients (88%). Only one respondent offered a dedicated service for patients with RA. Respondents indicated that the primary mode of accessing podiatry was by self-referral (68%). Significant variation was observed regarding access to disease and foot specific assessments and treatment strategies. Assessment methods such as administration of patient reported outcome measures, vascular and neurological assessments were not conducted by all respondents. Similarly, routine foot care strategies such as prescription of foot orthoses, foot health advice and footwear were not employed by all respondents.Conclusions: The results identified issues in foot care provision which should be explored through further research. Foot care provision in NSW does not appear to meet the current recommended standards for the management of foot problems in people who have RA. Improvements to foot care could be undertaken in terms of providing better access to examination techniques and treatment strategies that are recommended by evidence based treatment paradigms. © 2013 Hendry et al.; licensee BioMed Central Ltd

    The Hubble Space Telescope Extragalactic Distance Scale Key Project. X. The Cepheid Distance to NGC 7331

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    The distance to NGC 7331 has been derived from Cepheid variables observed with HST/WFPC2, as part of the Extragalactic Distance Scale Key Project. Multi-epoch exposures in F555W (V) and F814W (I), with photometry derived independently from DoPHOT and DAOPHOT/ALLFRAME programs, were used to detect a total of 13 reliable Cepheids, with periods between 11 and 42 days. The relative distance moduli between NGC 7331 and the LMC, imply an extinction to NGC 7331 of A_V = 0.47+-0.15 mag, and an extinction-corrected distance modulus to NGC 7331 of 30.89+-0.14(random) mag, equivalent to a distance of 15.1 Mpc. There are additional systematic uncertainties in the distance modulus of +-0.12 mag due to the calibration of the Cepheid Period-Luminosity relation, and a systematic offset of +0.05+-0.04 mag if we applied the metallicity correction inferred from the M101 results of Kennicutt et al 1998.Comment: To be published in The Astrophysical Journal, 1998 July 1, v501 note: Figs 1 and 2 (JPEG files) and Fig 7 (multipage .eps file) need to be viewed/printed separatel
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