Properties of tetrasulphur tetranitride in some reactive solvents

This thesis describes -1. The completion of the preliminary investigation of S(_4)N(_4)/SOCl(_2)/MCl(_x) systems commenced by Dr. J.S. Padley (Ph.D. Thesis, University of Durham, July 1967). 2. The carrying out of a more detailed study of the S(_4)N(_4)/SOCl(_2)/AlCl(_3) and S(_4)N(_4)/SOCl(_2)/FeCl(_3) systems (which the above noted preliminary investigation indicated would be the most satisfactory systems for more detailed study).3. The investigation of some S(_4)N(_4)/(constant metal chloride)/(varying solvent related to SOCl(_2) systems; since SOCl(_2) plays an active role in the S(_4)N(_4)/SOCl(_2)/MCl(_x) systems, the effect of varying the solvent used repays study. It has been found that most of the products obtained from the S(_4)N(_4)/ SOCl(_2)/MCl(_x) system could be grouped into only five categories, by the criterion of near infrared spectrum: it is believed that this correlation will be of particular value as more structural data become available. In the case of most of the compounds prepared, the group of near infrared spectra into which the product obtained from MCl(_x) falls can be tentatively correlated with the efficiency of MCl(_x) as a chlorination catalyst. It is shown that the systems S(_4)N(_4)/MCl(_x)/SO(_2)Cl(_2), and.S(_4)N(_4)/MCl(_x)/SCl(_2), are likely to justify an extensive investigation on the scale of that made into S(_4)N(_4)/MCl(_x)/SOCl(_2) systems. Results are discussed generally with a view to assisting the understanding and systematisation of (metal-)sulphur-nitrogen(-chlorine) chemistry as a whole, and particularly with reference to the likely structures of the products obtained, which products are believed to Include a number of compounds novel to sulphur-nitrogen chemistry

Speckle Statistics in Adaptively Corrected Images

(abridged) Imaging observations are generally affected by a fluctuating background of speckles, a particular problem when detecting faint stellar companions at small angular separations. Knowing the distribution of the speckle intensities at a given location in the image plane is important for understanding the noise limits of companion detection. The speckle noise limit in a long-exposure image is characterized by the intensity variance and the speckle lifetime. In this paper we address the former quantity through the distribution function of speckle intensity. Previous theoretical work has predicted a form for this distribution function at a single location in the image plane. We developed a fast readout mode to take short exposures of stellar images corrected by adaptive optics at the ground-based UCO/Lick Observatory, with integration times of 5 ms and a time between successive frames of 14.5 ms ($\lambda=2.2$ $\mu$m). These observations temporally oversample and spatially Nyquist sample the observed speckle patterns. We show, for various locations in the image plane, the observed distribution of speckle intensities is consistent with the predicted form. Additionally, we demonstrate a method by which $I_c$ and $I_s$ can be mapped over the image plane. As the quantity $I_c$ is proportional to the PSF of the telescope free of random atmospheric aberrations, this method can be used for PSF calibration and reconstruction.Comment: 7 pages, 4 figures, ApJ accepte

UK construction safety: a zero paradox?

The zero accident mantra has become embedded within the safety discourse of large UK construction organisations, but the extent to which zero-focused approaches yield reductions in accident frequency is yet to be empirically investigated. By way of an evidence-based critique, we examine the relationship between major accidents and zero approaches by drawing on Health and Safety Executive accident data over a 4 year period, together with an analysis of major contractors’ safety approaches. This reveals that working on a project subject to a zero safety policy or programme actually appears to slightly increase the likelihood of having a serious life-changing accident or fatality; a possible ‘zero paradox’. Although these findings should be treated with caution, they suggest that the apparent trend towards abandoning zero amongst some large organisations is well-founded. As such, if zero policies stymie learning whilst failing to reduce accidents, the need for a countervailing discourse is clear

Electrically pumped semiconductor laser with low spatial coherence and directional emission

We design and fabricate an on-chip laser source that produces a directional beam with low spatial coherence. The lasing modes are based on the axial orbit in a stable cavity and have good directionality. To reduce the spatial coherence of emission, the number of transverse lasing modes is maximized by fine-tuning the cavity geometry. Decoherence is reached in a few nanoseconds. Such rapid decoherence will facilitate applications in ultrafast speckle-free full-field imaging

Identifying the factors that influence innovation championing behaviour in construction support services organisations: a review of the role of middle management

W065 Organisation and Management of Construction Postgraduate Research: Paper ID: 542Innovation has been considered an important means by which organisations seek to achieve advantage over competition and for improving performance in today's highly competitive business environment. A number of factors have been identified as influencing innovation in project-based construction organisations. These include internal factors such as organisational culture, climate, leadership style and exogenous influences such as clients. Although research recognises how important it is for senior management to create an environment conducive to innovation, there is little understanding of how these internal and external factors interact to impact on innovativeness. This paper reviews relevant literature on innovation, organisational culture, organisational climate and leadership style while examining how they combine with external factors to promote innovation in construction support services organisations. The study particularly focuses on the role of key organisational actors with responsibility for developing a climate to facilitate innovation at the divisional or business unit level. The review reveals that efforts to develop a climate that promotes innovation championing behaviour among project managers will be influenced by the organizational culture, leadership style and the extent of external influence on project delivery. The study further reveals the importance of middle managers in promoting innovation. A methodology is presented for examining the role of this key managerial constituency and the ways in which they can enable or impede the innovation process.postprintThe 2010 World Congress of CIB on Building a Better World, University of Salford, Salford, U.K., 10-14 May 2010. In Proceedings: TG65 and W065 - Special Track. 18th CIB World Building Congress, 2010, p. 434-44

Thinking the ontological politics of managerial and critical performativities: an examination of project failure

Recent contributions within Critical Management Studies have argued for critical engagements with performativity to acknowledge and advance the plurality of performance calculi within organizations. However, even critically minded authors persist in deploying managerial calculi of performance when criticizing the failure of management on its own terms. Equally, interpretive analyses of performance narratives as discursive power games have thus far offered little substantive challenge to managerial understandings of performativity, as orientated around maxims of efficiency, control and profit. Positioned against these managerialist and conservative tendencies in extant understandings of performativity, we draw together the ANT- derived notions of ontological performativity and politics, alongside empirical research on projects, and specifically project failure, to propose that if ontologies are performative, multiple, and political, then performativities are ontological, multiple and political, and are thus capable of being realized otherwise; but crucially, we can advance this thesis only if we better understand how managerial performativity simultaneously others and depends on that which is outside it: an absent hinterland of different performative realities. This theoretical move challenges how we might not only understand but assemble multiple performed realities — demanding new methodological, analytical and political resources and responses to engage with performativities

Who reads the project file? Exploring the power effects of knowledge tools in construction project management

Various critical authors have questioned the salience, efficacy and power effects of formal project management bodies of knowledge (PMBoKs). As a result project management knowledge tools are increasingly being conceptualized along more flexible, adaptable, reflexive, democratic and informal terms. A central driver for this shift is that PM knowledge will be more relevant and useful for practitioners if it can be reflexively tailored to fit local project scenarios, emergent problems and different communities of practice, rather than projects being structured to fit generic ‘best practice’ ideals. Hence new knowledge tools increasingly would appear critical to alleviate various detrimental power effects associated with bureaucratic knowledge practices within project‐based industries, not least construction. This assumption is examined through a study of a formal and codified project management knowledge tool—a project file—within a small team of project practitioners in a large civil engineering consultancy. Various concepts of power related to actor‐network theory (ANT) are mobilized to understand how non‐human artefacts can enact power and knowledge in nuanced ways within organizations. This theoretically informed study will aid both researchers and practitioners interested in the consequences of developing prescriptive or reflexive project management knowledge within construction contexts and beyond

Beyond scoring: facilitating enhanced evaluation of the design quality of NHS healthcare buildings

The evaluation of design quality using prescribed instruments, as now mandated by the UK National Health Service (NHS), provides a research opportunity to acquire understanding of the social interaction of the project stakeholder groups when they are engaged in design evaluation activities. This paper argues that there is a pressing need for such a study, as without it, such evaluations may be unnecessarily limited. This paper argues for a fresh and pluralistic approach to be applied to the evaluation of the design quality of NHS healthcare facilities which complements the methods currently used which are enshrined within prescribed instruments. The new approach uses an interpretative research paradigm to understand the social interactions of the project stakeholders whilst they use the prescribed instruments. The decision to adopt such a pluralistic approach is discussed. The users of this work may include those who seek to improve the design quality of NHS healthcare buildings

Beyond scoring: advancing a new approach to the design evaluation of NHS buildings

The engagement of project stakeholders in the design evaluation of National Health Service (NHS) buildings is critiqued to evaluate the current effectiveness of NHS policy which prescribes the use of quantitative, positivist survey instruments to capture stakeholder views. An alternative conceptual framework for design evaluation is presented that privileges the practice of design evaluation as the social interaction of project stakeholders. Empirical evidence from two longitudinal case studies of newly-constructed mental health facilities illustrate the success of this innovative approach in improving patient healthcare outcomes and reducing operating costs. It elucidates and enhances both the praxis and practices stimulated by current approaches to design evaluation. It raises important implications for the future development of UK Government policy to substantively improve the design quality of NHS healthcare buildings and, in turn, improve patient healthcare outcomes