702 research outputs found

    Autoclave design for high pressure-high temperature corrosion studies

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    Acknowledgements The authors gratefully acknowledge the contribution of Steve Cawley of John Cardwell Limited and Jim Herrmann of Cortest Inc. for the manufacture of the autoclave and for the permission to use the vessel design schematic drawings (Figures 8 and 9) in the paper; these figures are not to be used for production without the express written permission of Cortest Inc. The assistance of the technical staff of the School of Engineering Central Workshop is much appreciated.Peer reviewedPostprin

    Heavy Craft Work in the Middle School

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    While the coming of the middle school clearly presents teachers with a wide range of opportunities for exciting new work the problems involved in the new enterprise are equally clear. Secondary teachers ask themselves to what extent their approach and subject matter will be applicable to younger children; their· junior colleagues, teachers of general subjects in the main, consider what increased degree of specialization will be required of them. In no subject are the opportunities and problems more apparent than in craft. A speaKer at the Exeter conference reported in Middle Schools - Themes in Education no. 14 (p 15) was enthusiastic about craft opportunities. 'The middle school provides two tremendous advantages. One, boys and girls could have equal opportunity in these schools and secondly a child can start specialised craft work before the age of eleven.' The section on craft in this publication is helpful, but useful references in this area are not abundant. In Towards the Middle School, DES Education Pamphlet no. 57, good examples are given of planning for heavy craft work. The Middle School - a Symposium comprises eight articles which first appeared in The Teacher and which embody a lot of good sense. Two very good articles on the subject of this paper appeared in the TES of 24 July 1970. There is a need for a lot more discussion, however, on what wood and metal work can be done with the middle school age group, what place it should have in the timetable and who should teach it

    A radio-frequency Bose–Einstein condensate magnetometer

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    We report on a radio frequency magnetometer employing a Bose–Einstein condensate of 87Rb atoms held in a dipole trap. An AC sensitivity of [Formula: see text] is achieved at a probing volume of [Formula: see text], leading to a volume-normalized sensitivity of [Formula: see text]. At larger probing volumes with the atoms released from the magnetic trap used in the initial phase of the evaporation sequence, the AC sensitivity is improved to [Formula: see text], allowing a two-mode approach for applications requiring improved sensitivity. Immediate application in high-resolution electromagnetic induction imaging is expected when compared to performance of other induction-based imaging platforms

    Identification of long-duration noise transients in LIGO and Virgo

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    The LIGO and Virgo detectors are sensitive to a variety of noise sources, such as instrumental artifacts and environmental disturbances. The Stochastic Transient Analysis Multi-detector Pipeline (STAMP) has been developed to search for long-duration (t\gtrsim1s) gravitational-wave (GW) signals. This pipeline can also be used to identify environmental noise transients. Here we present an algorithm to determine when long-duration noise sources couple into the interferometers, as well as identify what these noise sources are. We analyze the cross-power between a GW strain channel and an environmental sensor, using pattern recognition tools to identify statistically significant structure in cross-power time-frequency maps. We identify interferometer noise from airplanes, helicopters, thunderstorms and other sources. Examples from LIGO's sixth science run, S6, and Virgo's third scientific run, VSR3, are presented.Comment: 10 pages, 7 figures, Gravitational-wave Physics & Astronomy Worksho

    Fermiology via the electron momentum distribution

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    Investigations of the Fermi surface via the electron momentum distribution reconstructed from either angular correlation of annihilation radiation (or Compton scattering) experimental spectra are presented. The basis of these experiments and mathematical methods applied in reconstructing three-dimensional densities from line (or plane) projections measured in these experiments are described. The review of papers where such techniques have been applied to study the Fermi surface of metallic materials with showing their main results is also done.Comment: 22 pages, 9 Figures, 4 Table

    The visible effect of a very heavy magnetic monopole at colliders

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    If a heavy Dirac monopole exists, the light-to-light scattering below the monopole production threshold is enhanced due to strong coupling of monopoles to photons. At the next Linear Collider with electron beam energy 250 GeV this photon pair production could be observable at monopole masses less than 2.5-6.4 TeV in the e+ee^+e^- mode or 3.7-10 TeV in the γγ\gamma\gamma mode, depending on the monopole spin. At the upgraded Tevatron such an effect is expected to be visible at monopole masses below 1-2.5 TeV. The strong dependence on the initial photon polarizations allows to find the monopole spin in experiments at e+ee^+e^- and γγ\gamma\gamma colliders. We consider the ZγZ\gamma production and the 3γ3\gamma production at e+ee^+e^- and pppp or ppˉp\bar{p} colliders via the same monopole loop. The possibility to discover these processes is significantly lower than that of the γγ\gamma\gamma case.Comment: 18 pages, 2 figures, RevTe

    Diagnostic criteria for cancer cachexia: Reduced food intake and inflammation predict weight loss and survival in an international, multi-cohort analysis

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    Abstract Background Cancer‐associated weight loss (WL) associates with increased mortality. International consensus suggests that WL is driven by a variable combination of reduced food intake and/or altered metabolism, the latter often represented by the inflammatory biomarker C‐reactive protein (CRP). We aggregated data from Canadian and European research studies to evaluate the associations of reduced food intake and CRP with cancer‐associated WL (primary endpoint) and overall survival (OS, secondary endpoint). Methods The data set included a total of 12,253 patients at risk for cancer‐associated WL. Patient‐reported WL history (% in 6 months) and food intake (normal, moderately, or severely reduced) were measured in all patients; CRP (mg/L) and OS were measured in N = 4960 and N = 9952 patients, respectively. All measures were from a baseline assessment. Clinical variables potentially associated with WL and overall survival (OS) including age, sex, cancer diagnosis, disease stage, and performance status were evaluated using multinomial logistic regression MLR and Cox proportional hazards models, respectively. Results Patients had a mean weight change of −7.3% (±7.1), which was categorized as: ±2.4% (stable weight; 30.4%), 2.5–5.9% (19.7%), 6.0–10.0% (23.2%), 11.0–14.9% (12.0%), ≥15.0% (14.6%). Normal food intake, moderately, and severely reduced food intake occurred in 37.9%, 42.8%, and 19.4%, respectively. In MLR, severe WL (≥15%) (vs. stable weight) was more likely (P  100 mg/L: OR 2.30 (95% CI 1.62–3.26)]. Diagnosis, stage, and performance status, but not age or sex, were significantly associated with WL. Median OS was 9.9 months (95% CI 9.5–10.3), with median follow‐up of 39.7 months (95% CI 38.8–40.6). Moderately and severely reduced food intake and CRP independently predicted OS (P < 0.0001). Conclusions Modelling WL as the dependent variable is an approach that can help to identify clinical features and biomarkers associated with WL. Here, we identify criterion values for food intake impairment and CRP that may improve the diagnosis and classification of cancer‐associated cachexia

    Response of electrically coupled spiking neurons: a cellular automaton approach

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    Experimental data suggest that some classes of spiking neurons in the first layers of sensory systems are electrically coupled via gap junctions or ephaptic interactions. When the electrical coupling is removed, the response function (firing rate {\it vs.} stimulus intensity) of the uncoupled neurons typically shows a decrease in dynamic range and sensitivity. In order to assess the effect of electrical coupling in the sensory periphery, we calculate the response to a Poisson stimulus of a chain of excitable neurons modeled by nn-state Greenberg-Hastings cellular automata in two approximation levels. The single-site mean field approximation is shown to give poor results, failing to predict the absorbing state of the lattice, while the results for the pair approximation are in good agreement with computer simulations in the whole stimulus range. In particular, the dynamic range is substantially enlarged due to the propagation of excitable waves, which suggests a functional role for lateral electrical coupling. For probabilistic spike propagation the Hill exponent of the response function is α=1\alpha=1, while for deterministic spike propagation we obtain α=1/2\alpha=1/2, which is close to the experimental values of the psychophysical Stevens exponents for odor and light intensities. Our calculations are in qualitative agreement with experimental response functions of ganglion cells in the mammalian retina.Comment: 11 pages, 8 figures, to appear in the Phys. Rev.
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