Patches for Repairing Ceramics and Ceramic-Matrix Composites

Patches consisting mostly of ceramic fabrics impregnated with partially cured polymers and ceramic particles are being developed as means of repairing ceramics and ceramic-matrix composites (CMCs) that must withstand temperatures above the melting points of refractory metal alloys. These patches were conceived for use by space-suited, space-walking astronauts in repairing damaged space-shuttle leading edges: as such, these patches could be applied in the field, in relatively simple procedures, and with minimal requirements for specialized tools. These design characteristics also make the patches useful for repairing ceramics and CMCs in terrestrial settings. In a typical patch as supplied to an astronaut or repair technician, the polymer would be in a tacky condition, denoted as an A stage, produced by partial polymerization of a monomeric liquid. The patch would be pressed against the ceramic or CMC object to be repaired, relying on the tackiness for temporary adhesion. The patch would then be bonded to the workpiece and cured by using a portable device to heat the polymer to a curing temperature above ambient temperature but well below the maximum operating temperature to which the workpiece is expected to be exposed. The patch would subsequently become pyrolized to a ceramic/glass condition upon initial exposure to the high operating temperature. In the original space-shuttle application, this exposure would be Earth-atmosphere-reentry heating to about 3,000 F (about 1,600 C). Patch formulations for space-shuttle applications include SiC and ZrO2 fabrics, a commercial SiC-based pre-ceramic polymer, and suitable proportions of both SiC and ZrO2 particles having sizes of the order of 1 m. These formulations have been tailored for the space-shuttle leading-edge material, atmospheric composition, and reentry temperature profile so as to enable repairs to survive re-entry heating with expected margin. Other formulations could be tailored for specific terrestrial applications

Ceramic Paste for Patching High-Temperature Insulation

A ceramic paste that can be applied relatively easily, either by itself or in combination with one or more layer(s) of high-temperature ceramic fabrics, such as silicon carbide or zirconia, has been invented as a means of patching cracks or holes in the reinforced carbon-carbon forward surfaces of a space shuttle in orbit before returning to Earth. The paste or the paste/fabric combination could also be used to repair rocket-motor combustion chambers, and could be used on Earth to patch similar high-temperature structures. The specified chemical composition of the paste admits of a number of variations, and the exact proportions of its constituents are proprietary. In general, the paste consists of (1) silicon carbide, possibly with addition of (2) hafnium carbide, zirconium carbide, zirconium boride, silicon tetraboride, silicon hexaboride, or other metal carbides or oxides blended with (3) a silazane-based polymer. Because the paste is viscous and sticky at normal terrestrial and outer-space ambient temperatures, high-temperature ceramic fabrics such as silicon carbide or zirconia fabric impregnated with the paste (or the paste alone) sticks to the damaged surface to which it is applied. Once the patch has been applied, it is smoothed to minimize edge steps as required [forward-facing edge steps must be < or equal to 0.030 in. (< or equal to 0.76 mm) in the original intended space-shuttle application]. The patch is then heated to a curing temperature thereby converting it from a flexible material to a hard, tough material. The curing temperature is 375 to 450 F (approx.190 to 230 C). In torch tests and arc-jet tests, the cured paste was found to be capable of withstanding a temperature of 3,500 F (approx. 1,900 C) for 15 minutes. As such, the material appears to satisfy the requirement, in the original space-shuttle application, to withstand re-entry temperatures of approx.3,000 F (approx. 1,600 C)

Identifying and tracking key climate adaptation actors in the UK

To understand how climate adaptation planning and decision-making will progress, a better understanding is needed as to which organisations are expected to take on key responsibilities. Methodological challenges have impeded efforts to identify and track adaptation actors beyond the coarse scale of nation states. Yet, for effective adaptation to succeed, who do national governments need to engage, support and encourage? Using the UK as a case study, we conducted a systematic review of official government documents on climate adaptation, between 2006 and 2015, to understand which organisations are identified as key to future adaptation efforts and tracked the extent to which these organisations changed over time. Our unique longitudinal dataset found a very large number of organisations (n = 568). These organisations varied in size (small-medium enterprises to large multinationals), type (public, private and not-for-profit), sector (e.g. water, energy, transport and health), scale (local, national and international), and roles and responsibilities (policymaking, decision-making, knowledge production, retail). Importantly, our findings reveal a mismatch between official government policies that repeatedly call on private organisations to drive adaptation, on the one hand, and a clear dominance of the public sector on the other hand. Yet, the capacity of organisations to fulfil the roles and responsibilities assigned to them, particularly in the public sector, is diminishing. Unless addressed, climate adaptation actions could be assigned to those either unable, or unwilling, to implement them

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry

Search for relativistic magnetic monopoles with five years of the ANTARES detector data

[EN] A search for magnetic monopoles using five years of data recorded with the ANTARES neutrino telescope from January 2008 to December 2012 with a total live time of 1121 days is presented. The analysis is carried out in the range b>0.6 of magnetic monopole velocities using a strategy based on run-by-run Monte Carlo simulations. No signal above the background expectation from atmospheric muons and atmospheric neutrinos is observed, and upper limits are set on the magnetic monopole flux ranging from 5.7x10-16 to 1.5x10-18 cm-2 . s-1.sr-1.The authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'energie atomique et aux energies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), IdEx program and UnivEarthS Labex program at Sorbonne Paris Cite (ANR-10-LABX-0023 and ANR-11-IDEX-0005-02), Labex OCEVU (ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Stichting voor Fundamenteel Onderzoek der Materie (FOM), Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; National Authority for Scientific Research (ANCS), Romania; Ministerio de Economia y Competitividad (MINECO): Plan Estatal de Investigacion (refs. FPA2015-65150-C3-1-P, -2-P and -3-P, (MINECO/FEDER)), Severo Ochoa Centre of Excellence and MultiDark Consolider (MINECO), and Prometeo and Grisolia programs (Generalitat Valenciana), Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilitiesAlbert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Ardid Ramírez, M.; Aubert, J.; Avgitas, T.... (2017). Search for relativistic magnetic monopoles with five years of the ANTARES detector data. Journal of High Energy Physics (Online). (7):1-16. https://doi.org/10.1007/JHEP07(2017)054S1167P.A.M. Dirac, Quantized Singularities in the Electromagnetic Field, Proc. Roy. Soc. Lond. A 133 (1931) 60 [ INSPIRE ].G. ’t Hooft, Magnetic Monopoles in Unified Gauge Theories, Nucl. Phys. B 79 (1974) 276 [ INSPIRE ].A.M. Polyakov, Particle Spectrum in the Quantum Field Theory, JETP Lett. 20 (1974) 194 [ INSPIRE ].G. Lazarides, C. Panagiotakopoulos and Q. Shafi, Magnetic Monopoles From Superstring Models, Phys. Rev. Lett. 58 (1987) 1707 [ INSPIRE ].Y.M. Cho and D. Maison, Monopoles in Weinberg-Salam model, Phys. Lett. B 391 (1997) 360 [ hep-th/9601028 ] [INSPIRE].Particle Data Group collaboration, C. Patrignani et al., Review of Particle Physics, Chin. Phys. C 40 (2016) 100001 [ INSPIRE ].L. Patrizii and M. Spurio, Status of Searches for Magnetic Monopoles, Ann. Rev. Nucl. Part. Sci. 65 (2015) 279 [ arXiv:1510.07125 ] [INSPIRE].ATLAS collaboration, Search for magnetic monopoles and stable particles with high electric charges in 8 TeV pp collisions with the ATLAS detector, Phys. Rev. D 93 (2016) 052009 [ arXiv:1509.08059 ] [ INSPIRE ].MoEDAL collaboration, B. Acharya et al., Search for magnetic monopoles with the MoEDAL prototype trapping detector in 8 TeV proton-proton collisions at the LHC, JHEP 08 (2016) 067 [ arXiv:1604.06645 ] [INSPIRE].MoEDAL collaboration, B. Acharya et al., Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13 TeV Proton-Proton Collisions at the LHC, Phys. Rev. Lett. 118 (2017) 061801 [ arXiv:1611.06817 ] [INSPIRE].T.W.B. Kibble, Topology of Cosmic Domains and Strings, J. Phys. A 9 (1976) 1387 [ INSPIRE ].J. Preskill, Cosmological Production of Superheavy Magnetic Monopoles, Phys. Rev. Lett. 43 (1979) 1365 [ INSPIRE ].A.H. Guth, The Inflationary Universe: A Possible Solution to the Horizon and Flatness Problems, Phys. Rev. D 23 (1981) 347 [ INSPIRE ].D. Ryu, H. Kang and P.L. Biermann, Cosmic magnetic fields in large scale filaments and sheets, Astron. Astrophys. 335 (1998) 19 [ astro-ph/9803275 ] [ INSPIRE ].E.N. Parker, The Origin of Magnetic Fields, Astrophys. J 160 (1970) 383.ANTARES collaboration, M. Ageron et al., ANTARES: the first undersea neutrino telescope, Nucl. Instrum. Meth. A 656 (2011) 11 [ arXiv:1104.1607 ] [INSPIRE].ANTARES collaboration, S. Adrian-Martinez et al., Search for Relativistic Magnetic Monopoles with the ANTARES Neutrino Telescope, Astropart. Phys. 35 (2012) 634 [ arXiv:1110.2656 ] [ INSPIRE ].IceCube collaboration, M.G. Aartsen et al., Searches for Relativistic Magnetic Monopoles in IceCube, Eur. Phys. J. C 76 (2016) 133 [ arXiv:1511.01350 ] [INSPIRE].ANTARES collaboration, J.A. Aguilar et al., The data acquisition system for the ANTARES Neutrino Telescope, Nucl. Instrum. Meth. A 570 (2007) 107 [ astro-ph/0610029 ] [INSPIRE].D.R. Tompkins, Total energy loss and Čerenkov emission from monopoles, Phys. Rev. 138 (1965) B248.Y. Kazama, C.N. Yang and A.S. Goldhaber, Scattering of a Dirac Particle with Charge Ze by a Fixed Magnetic Monopole, Phys. Rev. D 15 (1977) 2287 [ INSPIRE ].S.P. Ahlen, Monopole Track Characteristics in Plastic Detectors, Phys. Rev. D 14 (1976) 2935 [ INSPIRE ].S.P. Ahlen, Stopping Power Formula for Magnetic Monopoles, Phys. Rev. D 17 (1978) 229 [ INSPIRE ].J. Derkaoui et al., Energy losses of magnetic monopoles and of dyons in the earth, Astropart. Phys. 9 (1998) 173 [ INSPIRE ].CERN Application Software Group, GEANT 3.21 Detector Description and Simulation Tool, CERN Program Library Long Writeup W5013 (1993).G. Carminati, A. Margiotta and M. Spurio, Atmospheric MUons from PArametric formulas: A fast GEnerator for neutrino telescopes (MUPAGE), Comput. Phys. Commun. 179 (2008) 915 [ arXiv:0802.0562 ] [INSPIRE].Y. Becherini, A. Margiotta, M. Sioli and M. Spurio, A parameterisation of single and multiple muons in the deep water or ice, Astropart. Phys. 25 (2006) 1 [ hep-ph/0507228 ] [INSPIRE].J. Brunner, ANTARES simulation tools, in proceedings of The VLVnT workshop, Amsterdam (2003), http://www.vlvnt.nl/proceedings.pdf .ANTARES collaboration, A. Margiotta, Common simulation tools for large volume neutrino detectors, Nucl. Instrum. Meth. A 725 (2013) 98 [ INSPIRE ].V. Agrawal, T.K. Gaisser, P. Lipari and T. Stanev, Atmospheric neutrino flux above 1-GeV, Phys. Rev. D 53 (1996) 1314 [ hep-ph/9509423 ] [INSPIRE].G.D. Barr, T.K. Gaisser, S. Robbins and T. Stanev, Uncertainties in Atmospheric Neutrino Fluxes, Phys. Rev. D 74 (2006) 094009 [ astro-ph/0611266 ] [INSPIRE].L. Fusco and A. Margiotta, The Run-by-Run Monte Carlo simulation for the ANTARES experiment, EPJ Web Conf. 116 (2016) 02002.ANTARES collaboration, J.A. Aguilar et al., A fast algorithm for muon track reconstruction and its application to the ANTARES neutrino telescope, Astropart. Phys. 34 (2011) 652 [ arXiv:1105.4116 ] [INSPIRE].ANTARES collaboration, S. Adrian-Martinez et al., Searches for Point-like and extended neutrino sources close to the Galactic Centre using the ANTARES neutrino Telescope, Astrophys. J. 786 (2014) L5 [ arXiv:1402.6182 ] [INSPIRE].G.J. Feldman and R.D. Cousins, A unified approach to the classical statistical analysis of small signals, Phys. Rev. D 57 (1998) 3873 [ physics/9711021 ] [INSPIRE].G.C. Hill and K. Rawlins, Unbiased cut selection for optimal upper limits in neutrino detectors: The model rejection potential technique, Astropart. Phys. 19 (2003) 393 [ astro-ph/0209350 ] [ INSPIRE ].ANTARES collaboration, J.A. Aguilar et al., Zenith distribution and flux of atmospheric muons measured with the 5-line ANTARES detector, Astropart. Phys. 34 (2010) 179 [ arXiv:1007.1777 ] [ INSPIRE ].ANTARES collaboration, S. Adrian-Martinez et al., Measurement of the atmospheric ν μ energy spectrum from 100 GeV to 200 TeV with the ANTARES telescope, Eur. Phys. J. C 73 (2013) 2606 [ arXiv:1308.1599 ] [INSPIRE].ANTARES collaboration, S. Adrian-Martinez et al., First Search for Point Sources of High Energy Cosmic Neutrinos with the ANTARES Neutrino Telescope, Astrophys. J. 743 (2011) L14 [ arXiv:1108.0292 ] [INSPIRE].ANTARES collaboration, P. Amram et al., The ANTARES optical module, Nucl. Instrum. Meth. A 484 (2002) 369 [ astro-ph/0112172 ] [INSPIRE].ANTARES collaboration, J.A. Aguilar et al., Transmission of light in deep sea water at the site of the ANTARES Neutrino Telescope, Astropart. Phys. 23 (2005) 131 [ astro-ph/0412126 ] [ INSPIRE ].MACRO collaboration, M. Ambrosio et al., Final results of magnetic monopole searches with the MACRO experiment, Eur. Phys. J. C 25 (2002) 511 [ hep-ex/0207020 ] [INSPIRE].BAIKAL collaboration, K. Antipin et al., Search for relativistic magnetic monopoles with the Baikal Neutrino Telescope, Astropart. Phys. 29 (2008) 366 [ INSPIRE ].KM3Net collaboration, S. Adrian-Martinez et al., Letter of intent for KM3NeT 2.0, J. Phys. G 43 (2016) 084001 [ arXiv:1601.07459 ] [INSPIRE]

Towards an ethical ecology of international service learning

International Service-Learning (ISL) is a pedagogical activity that seeks to blend student learning with community engagement overseas and the development of a more just society. ISL programmes have grown as educational institutions and non-governmental organisations have sought to achieve the goal of developing ‘global citizens’. However, Service Learning (SL) in general and International Service-Learning (ISL) in particular remain deeply under theorised. These educational initiatives provide policy makers with a practical response to their quest for a ‘Big Society’and present alluring pedagogical approaches for Universities as they react to reforms in Higher Education and seek to enhance both the student learning experience and graduate employability. After outlining the development of ISL in policy and practice, this paper draws on the rich tradition of ISL at one British university to argue that ISL is a form of engagement that has the potential to be ethical in character although we identify a number of factors that militate against this. Our contention is that ISL which promotes rationaland instrumental learning represents a deficit model and we therefore conceptualise ISL here as a transformative learning experience that evinces distinctly aesthetic and even spiritual dimensions. Upon this theoretical groundwork we lay the foundations for conceptualizing ISL in ways that ensure its ethical integrity

Aligning the CMS Muon Chambers with the Muon Alignment System during an Extended Cosmic Ray Run

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