2,111 research outputs found

    Commissioning of the Beam Interlock System for the TT40 and TT41 Transfer Lines of the SPS

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    The extraction area of LSS4 in the SPS and the TT40 and TT41 transfer lines have been equipped with a new interlock system to protect the machine elements against beam induced failure during operation with the high intensity CNGS beams. The system commissioning that was performed during the 2006 SPS run followed pre-defined commissioning procedures. An extensive WEB based documentation of the tests has been established to track the state of the interlock system, in particular of interlock references. This document presents a short summary of the commissioning as well as the complete documentation of the interlock tests

    Marginal benefit to South Asian economies from SO2 emissions mitigation and subsequent increase in monsoon rainfall

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    Sulphate aerosols are dominated by SO2 emissions from coal-burning for the Indian electricity sector and they are thought to have a short term but significant, negative impact on South Asian Summer Monsoon rainfall. This reduction in precipitation in turn can lead to reduced economic outputs, primarily through smaller agricultural yields. By bringing together estimates of (a) the impact of sulphate aerosols on precipitation and (b) the observed relationship between monsoon rainfall and GDP, we present a methodology to estimate the possible financial cost of this effect on the Indian economy and on its agricultural sector. Our preliminary estimate is that the derived benefits could be large enough that around 50% of India’s SO2 emissions could be economically mitigated at no cost or net benefit, although it should be noted that the large uncertainties in the underlying relationships mean that the overall uncertainty is also large. Comparison of the 1952–1981 and 1982–2011 periods indicates that the Indian economy may now be more resilient to variability of the monsoon rainfall. As such, a case could be made for action to reduce SO2 emissions, particularly in the crucial monsoon period. This would have a significant, positive effect on a crucial and large sector in India’s economy and the effects would be visible almost instantly. The recent growth in renewable energy sources in India and the consequent, reduced increase in coal burning means that further financial costs have already been avoided. This impact should be further investigated so that it can be included in cost-benefit analyses of different fuel types in the region. The significant uncertainties associated with these calculations are discussed

    Cosmological Consequences of String Axions

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    Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H_inf \apprge 10^13 GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T \apprle \Lambda_QCD.Comment: 27 pages, 4 figures; v2: References corrected; v3: Assumptions simplified, minor corrections, conclusions unchange

    Tuning the transition temperature of superconducting Ag/Pb films via the proximity effect

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    We report measurements of the transition temperature (TC) of superconducting films composed of various combinations of Ag and Pb layers. For samples with good electrical contact between the layers, the measured TC values show reasonable agreement with the Cooper model of the proximity effect. In poorly coupled samples, the normal layers appear to cause little if any suppression of the TC. We present a simple predictive expression for TC as a function of Ag content

    R. K. Narayanswami B.A.B.L. Engine Driver : Story-Telling and Memory in The Grandmother’s Tale, and Selected Stories

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    Much like the Nambi of this tale, R. K. Narayan has merited his reputation as a marvelous storyteller. Noted for his laser-beam focus on the closely-imagined Malgudi, he has come to be recognized as the Indian novelist, from whose pen many readers expected all the accumulated wisdom of the subcontinent\u27s abiding concern for transcendence. While such guru-ization amused Narayan, it also elicited his quietly sustained argument against procrustean templates by which the west insisted on reading him as typically Indian.

    Cosmological Inhomogeneities with Bose-Einstein Condensate Dark Matter

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    We consider the growth of cosmological perturbations to the energy density of dark matter during matter domination when dark matter is a scalar field that has undergone Bose-Einstein condensation. We study these inhomogeneities within the framework of both Newtonian gravity, where the calculation and results are more transparent, and General Relativity. The direction we take is to derive analytical expressions, which can be obtained in the small pressure limit. Throughout we compare our results to those of the standard cosmology, where dark matter is assumed pressureless, using our analytical expressions to showcase precise differences. We find, compared to the standard cosmology, that Bose-Einstein condensate dark matter leads to a scale factor, gravitational potential and density contrast that increase at faster rates.Comment: 17 pages, 2 figures; typos corrected, references adde

    Assessing the potential to use serious gaming in planning processes for sanitation designed for resource recovery

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    There is an urgent need for innovations in the sanitation sector to minimize environmental impacts and maximize resource recovery. Uptake of innovations may require changes in established technical practices, organisational norms and/or individual behaviours. Achieving change in any of these areas requires influencing cognitive, normative and relational learning processes. Serious games have been identified a potential tool for planners and environmental managers to influence such learning processes. This study designed the serious game RECLAIM to share knowledge about resource recovery from sanitation and to support attitude-change and collaboration between players. A structured framework was applied to assess if the game: 1) increased understanding of resource recovery (cognitive learning), 2) changed worldviews (normative learning), 3) led to more collaboration (relational learning), and 4) was a positive experience. Proof-of-concept testing of the game in Uganda found that it was positively received. The game provided cognitive learning on environmental and health impacts, resource recovery, and sanitation in general. Players gained an appreciation of the need for collaboration and it was deemed to have the potential to influence worldviews of a larger stakeholder group. Future recommendations include embedding the game in planning processes, including several gaming sessions that would strengthen cognition learning and the potential for changing practices

    Linear & Nonl. optics checks diring LHC injection tests

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    In early LHC commissioning, linear and “higher-order” polarity checks were performed for one octant per beam, by launching suitable free betatron oscillations and then inverting a magnet-circuit polarity or strength. Circuits tested included trim quadrupoles, skew quadrupoles, lattice sextupoles, sextupole spool-pieces, Landau octupoles, and skew sextupoles. A nonzero momentum offset was introduced to enhance the measurement quality. The lowintensity single-pass measurements proved sufficiently sensitive to verify the polarity and the amplitude of (almost) all circuits under investigation, as well as the alignment of some individual trim quadrupoles. A systematic polarity inversion detected by this measurement helped to pin down the origin of observed dispersion errors. Later, the periodic “ring dispersion” was reconstructed from the full first-turn trajectory of an injected off-momentum beam, by removing, at each location, the large incoming dispersion mismatch, forward-propagated via the optics model. Various combinations of inverted trim quadrupoles were considered in this model until reaching a good agreement of reconstructed dispersion and prediction
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