12,370 research outputs found

    FM contract relationships: from mobilisation to sustainable partnership

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    Purpose / theory Outsourcing is a fundamental business model for the Facilities Management (FM) industry. To enable sustained mutual success the parties involved must seek to understand the unique, socially constructed, and often highly complex situational realities of the organisational ecologies they are engaged in. The FM industry can unlock improved performance and strategic credibility through an appreciation of the need for different conversations. Design / methodology / approach Findings from two recent cases are considered. Data from two different client-contractor relationship situations was collected utilising a critical ethnographic research methodology; a phenomenological paradigm that acknowledges knowledge as socially constructed through language. A variant on Scott-Morgan‟s unwritten-rules coding method was used to analyse the data and justify the prevalent themes and issues presented. Findings Findings include the role of perceptions and assertions in the construction of social realities, change management implications, and how these impact on the traditional view of the client/contractor relationship. Ethnographic findings are typically context specific, therefore generalisations must be carefully considered. The key findings are however substantiated by existing FM outsourcing literature. Originality / value Highlights the practical importance of seeking to understand socially embedded realities for improved FM contract performance. Considers the human resource element of change via FM outsourcing. Takes a social constructivist approach to organisational sense-making. Uses examples from focused, critical ethnographies to explore existing FM contracting dynamics. Qualitative investigations into related organisational circumstances are encouraged to further develop an evidence base

    Wind tunnel buffet load measuring technique

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    Indirect force measurement technique estimates unsteady forces acting on elastic model during wind tunnel tests. Measurement of forces is practically insensitive to errors in aeroelastic scaling between model and full-scale structure, simplifying design, fabrication and dynamic calibration

    The Optical - Infrared Colors of CORALS QSOs: Searching for Dust Reddening Associated With High Redshift Damped Lyman Alpha Systems

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    The presence of dust in quasar absorbers, such as damped Lyman alpha (DLA) systems, may cause the background QSO to appear reddened. We investigate the extent of this potential reddening by comparing the optical-to-infrared (IR) colors of QSOs with and without intervening absorbers. Our QSO sample is based on the Complete Optical and Radio Absorption Line System (CORALS) survey of Ellison et al (2001). We have obtained near-simultaneous B and K band magnitudes for subset of the CORALS sample and supplemented our observations with further measurements published in the literature. To account for redshift-related color changes, the B-K colors are normalized using the Sloan Digital Sky Survey (SDSS) QSO composite. The mean normalized B-K color of the DLA sub-sample is +0.12, whereas the mean for the no-DLA sample is -0.10; both distributions have RMS scatters ~0.5. Neither a student's T-test nor a KS test indicate that there is any significant difference between the two color distributions. Based on simulations which redden the colors of QSOs with intervening DLAs, we determine a reddening limit which corresponds to E(B-V) < 0.04 (SMC-like extinction) at 99% confidence (3 sigma), assuming that E(B-V) is the same for all DLAs. Finally, we do not find any general correlation between absorber properties (such as [Fe/Zn] or neutral hydrogen column density) and B-K color. One of these two QSOs shows evidence for strong associated absorption from X-ray observations, an alternative explanation for its very red color. We conclude that the presence of intervening galaxies causes a minimal reddening of the background QSO.Comment: Accepted for publication in A

    An excess of damped Lyman alpha galaxies near QSOs

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    We present a sample of 33 damped Lyman alpha systems (DLAs) discovered in the Sloan Digital Sky Survey (SDSS) whose absorption redshifts (z_abs) are within 6000 km/s of the QSO's systemic redshift (z_sys). Our sample is based on 731 2.5 < z_sys < 4.5 non-broad-absorption-line (non-BAL) QSOs from Data Release 3 (DR3) of the SDSS. We estimate that our search is ~100 % complete for absorbers with N(HI) >= 2e20 cm^-2. The derived number density of DLAs per unit redshift, n(z), within v < 6000 km/s is higher (3.5 sigma significance) by almost a factor of 2 than that of intervening absorbers observed in the SDSS DR3, i.e. there is evidence for an overdensity of galaxies near the QSOs. This provides a physical motivation for excluding DLAs at small velocity separations in surveys of intervening 'field' DLAs. In addition, we find that the overdensity of proximate DLAs is independent of the radio-loudness of the QSO, consistent with the environments of radio-loud and radio-quiet QSOs being similar.Comment: Accepted for publication in MNRAS (13 pages, 6 figures

    On the role of injection in kinetic approaches to nonlinear particle acceleration at non-relativistic shock waves

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    The dynamical reaction of the particles accelerated at a shock front by the first order Fermi process can be determined within kinetic models that account for both the hydrodynamics of the shocked fluid and the transport of the accelerated particles. These models predict the appearance of multiple solutions, all physically allowed. We discuss here the role of injection in selecting the real solution, in the framework of a simple phenomenological recipe, which is a variation of what is sometimes referred to as thermal leakage. In this context we show that multiple solutions basically disappear and when they are present they are limited to rather peculiar values of the parameters. We also provide a quantitative calculation of the efficiency of particle acceleration at cosmic ray modified shocks and we identify the fraction of energy which is advected downstream and that of particles escaping the system from upstream infinity at the maximum momentum. The consequences of efficient particle acceleration for shock heating are also discussed

    Edgar Allan Poe and Science: Unraveling the Plot of the Universe

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    Edgar Allan Poe (1809-49) lived at the perfect time to write about several of the most dramatic technological developments ever recorded in history. Up until the nineteenth century, professional scientists were almost the exclusive agents for writing about science. However, during this period, non-professional writers also emerged as important conveyors of popular science news to the public. Though Poe was a lay writer, his popular writing conveyed several of the most important new discoveries of the Industrial Age. He also projected his views about how nineteenth-century technologies might impact civilizations of the future. Poe’s writing offers a key example of a widespread movement of thinkers who attempted to mediate the tensions and debates that were taking place in his lifetime between those who perceived and described the world from either the “Mechanical” or the “Romantic” approach. This study explores the ways that Poe wrote about science in poetry, non-fiction, and fiction. I argue that a review of his earlier science writing helps to unlock several of the enigmatic writings of his culminationg work, Eureka:A Prose Poem. The final chapter of this thesis concludes with an in-depth discussion of Eureka. In Eureka, Poe proposes that man’s literary works are imperfect. However, he contends that the Creator has written and executed a perfect “Plot of the Universe.” Poe attempts to unravel several of its deepest mysteries in a multi-genre work of poetry, history, science, and metaphysics. I argue that modern scholars of literature and science history can gain a clearer view of the ways that the nineteenth-century public received and understood information about science by exploring Poe’s science writing than has been provided in previous historical or literary scholarship

    Unusual Metal Abundances in a Pair of Damped Lyman Alpha Systems at z~2

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    We present high resolution spectroscopic observations of two neighbouring damped Lya systems (DLAs) along the same line of sight towards B2314-409. Due to their separation (v ~ 2000 km/s) and the high spectral resolution of the data, it is possible to fit not only the weak metal transitions, but also the separate HI absorption profiles. This has permitted, for the first time, a detailed study of metal abundances in two neighbouring galaxy-scale absorbers. The two DLAs have z_abs = 1.8573 and 1.8745 and have column densities log N(HI) = 20.9+/-0.1 and 20.1+/-0.2 respectively. We have determined abundances for a range of chemical elements, and find that BOTH absorbers towards B2314-409 have low alpha/Fe-peak abundances compared with other known DLAs. This indicates that not only has the recent star formation history of these absorbers been relatively passive, but that the group environment, or some other external factor, may have influenced this

    Ultrahard spectra of PeV neutrinos from supernovae in compact star clusters

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    Starburst regions with multiple powerful winds of young massive stars and supernova remnants are favorable sites for high-energy cosmic ray acceleration. A supernova shock colliding with a fast wind from a compact cluster of young stars allows the acceleration of protons to energies well above the standard limits of diffusive shock acceleration in an isolated SN. The proton spectrum in such a wind-supernova PeV accelerator is hard with a large flux in the high-energy-end of the spectrum producing copious gamma-rays and neutrinos in inelastic nuclear collisions. We argue that SN shocks in the Westerlund 1 cluster in the Milky Way may accelerate protons to about 40 PeV. Once accelerated, these CRs will diffuse into surrounding dense clouds and produce neutrinos with fluxes sufficient to explain a fraction of the events detected by IceCube Observatory from the inner Galaxy.Comment: 10 pages, 7 figures, MNRAS v.453, p.113-121, 201
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