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1
Neilands, Jessica. "Acid tolerance of Streptococcus mutans biofilms /." [Malmö, Sweden] : Malmö University, Faculty of Odontology, Department of Oral Biology, 2007. http://www.mah.se/muep.
Texte intégral
2
Rafelski, Helga E. "Muon regeneration in muon catalyzed dt-fusion." Doctoral thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/16012.
Texte intégralRésumé :
Includes bibliographical references.<br>The origin of the experimentally observed density dependence of the effective muon alpha sticking fraction will in muon catalyzed deuterium- tritium fusion has been comprehensively reanalyzed with the particular emphasis put on the density dependence of the stopping power in dense hydrogen. The main technical details and improvements in this work are: The (aμ)+ 2s and 2p states are treated independently and are assigned individual reaction rates. The essential muonic excitation rates have been recalculated taking into account finite nuclear mass effects. The stopping power for a charged projectile in liquid heavy hydrogen is modified to account for dynamic screening effects and a density dependent effective ionization potential. It is shown that the medium dependent stopping power for the (aμ)+ ion is the crucial entity controlling the density dependance of the effective sticking fraction. It is also pointed out that the muonic helium Ka X-ray yield and the sticking fraction at high density can not be simultaneously brought into agreement with the experimental results without invoking novel mechanisms suppressing Stark mixing in the (Heμ) L-shell.
3
Kôhei, Mukai Mobberley James. "Mugen for orchestra." Diss., UMK access, 2005.
Trouver le texte intégralRésumé :
Thesis (D.M.A.)--Conservatory of Music. University of Missouri--Kansas City, 2005.<br>"A disseration in music composition." Advisor: James Mobberley. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed Nov. 12, 2007. Online version of the print edition.
4
Chapman, Michael David. "The branching fraction of long-lived kaon going to muon-anti-muon." W&M ScholarWorks, 1992. https://scholarworks.wm.edu/etd/1539623816.
Texte intégralRésumé :
This thesis presents the results of a measurement of the branching fraction of the $K\sb{L}\to\mu\bar{\mu}$ decay. This decay is scGIM supressed in the Standard Model, and provides a useful test of that model. Additionally, the degree of deviation from the unitary limit provides a useful test for several other models. The experiment was performed at the Brookhaven National Laboratory Alternating Gradient Synchrotron facility. The apparatus consisted of a two-magnet mass spectrometer, together with dual electromagnetic and muon particle identification systems. A total of 281 $K\sb{L}\to\mu\bar{\mu}$ events were observed. Normalizing to the 15,768 $K\sb{L}\to\pi\bar{\pi}$ events observed results in a branching fraction of $\Gamma(K\sb{L}\to\mu\bar{\mu})/\Gamma(K\sb{L}\to$ all) = (7.6 $\pm$ 0.5) $\times$ 10$\sp{-9}$.
5
Hammarström, Susanna, and Esseros Camilla Johansson-. "Mun-till-mun-marknadsföring : Gräddfilen förbi mediebruset." Thesis, Högskolan i Borås, Institutionen Handels- och IT-högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-18515.
Texte intégralRésumé :
Varje dag överöser företag oss människor med budskap genom reklam ochannonser. Nya kanaler såsom bloggar, ett ökat utbud av TV-kanaler ochökningen av antalet svenska och utländska tidningar har bidragit till att flerreklambudskap trängs på marknaden. Vi människor har därför tvingats läraoss att stänga av och ignorera reklam. Därför uppfattar vi inte ens en bråkdelav alla de budskap som cirkulerar runt omkring oss. För företag gäller detdärför att hitta nya sätt att komma igenom kaoset och nå fram sina kunder.Istället för att använda sig av konventionella marknadsföringsmetoder somannonsering och TV-reklam, har företag börjat försöka få människor attprata om produkten. Det ligger i människans natur att prata och diskuteraolika samhällsfenomen. Människor pratar om företag, deras tjänster ochprodukter.Syftet med uppsatsen är att undersöka och beskriva hur olika företaguppfattar och arbetar med mun-till-mun-marknadsföring. I vår uppsats har viett hermeneutiskt förhållningssätt. Vi har gjort en kvalitativ studie av treolika företag som valts ut genom ett så kallat strategiskt urval.I uppsatsen använde vi oss av den induktiva ansatsen. Vi använde primärdatai form av intervjuer samt sekundärdata i form av litteratur. Empirin i våruppsats består av personliga intervjuer med en reklambyrå samt två andraföretag.Slutsatsen av vår undersökning är att företag uppfattar mun-till-munmarknadsföringsom när människor pratar om produkter med varandra. Desprider antingen positiv och/eller negativ information om produkten ellertjänsten. Företag tillämpar sällan mun-till-mun-marknadsföring direkt, då detär mycket svårt. Däremot arbetar de med metoden indirekt genom att dentraditionella marknadsföringen har som syfte att få människor attuppmärksamma produkten eller tjänsten och därefter prata om den. Vi kanäven konstatera att företag har en mycket positiv inställning till mun-tillmun-marknadsföring, då den jämfört med traditionell marknadsföring äreffektivare. Företag tror att människor litar och lyssnar mer på sina vännerän på traditionell reklam. Nackdelen med mun-till-mun-marknadsföring äratt den är svår att kontrollera.<br>Uppsatsnivå: C
6
Blombäck, Jacob. "Fenway corner - bakom muren." Thesis, KTH, Arkitektur, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-97458.
Texte intégralRésumé :
Avancerad program- och funktionsstudie i form av multi-use-byggnad uppbyggd kring ett badhus i urban miljö i stadsdelen Fenway i Boston. Byggnadens huvudteman är "den klättrande parken" och "bakom muren". Det förstnämna genom att det befintliga parkrummet invid byggnaden tematiskt ges en förlängning in i byggnaden och trappar sig uppåt i badets olika nivåer för att mynna i en södervänd takträdgård och soldäck högst upp. Temat kring muren uttrycks genom en massiv långsträckt byggnad mot gatan som skärmar av det södervända badet från den trafikerade gatan. Mot parkens lummiga träd vänder sig ett tredje objekt i form en glasad byggnad i fyra plan med café/restaurang och bibliotek med läsrum och studieplatser.
7
Pattenden, Paul Adam. "Muon studies of solids." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361930.
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8
Armstrong, Robert E. "Muon neutrino disappearance at MINOS." [Bloomington, Ind.] : Indiana University, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3380059.
Texte intégralRésumé :
Thesis (Ph.D.)--Indiana University, Dept. of Physics, 2009.<br>Title from PDF t.p. (viewed on Jul 19, 2010). Source: Dissertation Abstracts International, Volume: 70-12, Section: B, page: 7630. Adviser: Jon Urheim.
9
Forrest, David Alexander James. "The Muon Ionisation Cooling Experiment." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2839/.
Texte intégralRésumé :
Outstanding areas of ambiguity within our present understanding of the nature and behaviour of neutrinos warrant the construction of a dedicated future facility capable of investigating the likely parameter space for the theta 1,3 mixing angle, the Dirac CP violating phase and clarifying the neutrino mass hierarchy. A number of potential discovery venues have been proposed including the beta beam, superbeam and neutrino factory accelerator facilities. Of these, the neutrino factory significantly outperforms the others. A neutrino factory will deliver intense beams of 10^21 neutrinos per year, produced from muons decaying in storage rings. This specification, coupled with the constraints of the short muon lifetime warrant the inclusion of a novel cooling channel to reduce the phase space volume of the beam to fall within the acceptance of the acceleration system. Ionisation cooling is the only viable cooling technique with efficacy over the lifetime of the muon, however, it has yet to be demonstrated in practice. In a full cooling channel, a muon beam will traverse a periodic absorber and accelerator lattice consisting of low Z absorbers enclosed by focusing coils and accelerating radio-frequency cavities. Energy loss in the absorbers reduces both transverse and longitudinal momentum. The latter is restored by the accelerating cavities providing a net reduction in transverse momentum and consequently reducing the phase space volume of the muon beam. The Muon Ionisation Cooling Experiment (MICE), under construction at the ISIS synchrotron at Rutherford Appleton Laboratory seeks to provide both a first measurement and systematic study of ionisation cooling, demonstrated within the context of a single cell prototype of a cooling channel. The experiment will evolve incrementally toward its final configuration, with construction and scientific data taking schedules proceeding in parallel. The stated goal of MICE is to measure a fractional change in emittance of order 10% to an error of 1%. This thesis constitutes research into different aspects of MICE: design and implementation of the MICE configuration database, determination of the statistical errors and alignment tolerances associated with cooling measurements made using MICE, simulations and data analysis studying the performance of the luminosity monitor and a first analysis of MICE Step I data. A sophisticated information management solution based on a bi-temporal relational database and web service suite has been designed, implemented and tested. This system will enable the experiment to record geometry, calibration and cabling information in addition to beamline settings (including but not limited to magnet and target settings) and alarm handler limits. This information is essential both to provide an experimental context to the analysis user studying data at a later time and to experimenters seeking to reinstate previous settings. The database also allows corrections to be stored, for example to the geometry, whereby a later survey may clarify an incomplete description. The old and new geometries are both stored with reference to the same period of validity, indexed by the time they are added to the configuration database. This allows MICE users to recall both the best-known geometry of the experiment at a given time by default, as well as the history of what was known about the geometry as required. Such functionality is two dimensional in time, hence the choice of a bi-temporal database paradigm, enabling the collaboration to run new analyses with the most up to date knowledge of the experimental configuration and also repeat previous analyses which were based upon incomplete information. From Step III of MICE onwards, the phase space volume, or emittance, of the beam will be measured by two scintillating fibre trackers placed before and after the cooling cell. Since the two emittance measurements are made upon a similar sample of muons, the measurement errors are influenced by correlations. This thesis will show through an empirical approach that correlations act to reduce the statistical error by an order of magnitude. In order to meet its goals MICE must also quantify its systematic errors. A misalignment study is presented which investigates the sensitivity of the scintillating fibre trackers to translational and rotational misalignment. Tolerance limits of 1 mm and 0.3 mrad respectively allow MICE to meet the requirement that systematic errors due to misalignment of the trackers contribute no more than 10% of the total error. At present, MICE is in Step I of its development: building and commissioning a muon beamline which will be presented to a cooling channel in later stages of MICE. A luminosity monitor has been built and commissioned to provide a measurement of particle production from the target, normalise particle rate at all detectors and verify the physics models which will be used throughout the lifetime of MICE and onwards through to the development of a neutrino factory. Particle identification detectors have already been installed and allow the species of particles to be distinguished according to their time of flight. This has enabled a study of particle identification, particle momenta and simulated and experimental beam profiles at each time of flight detector. The widths of the beam profiles are sensitive to multiple scattering and magnetic effects, providing an opportunity to quantify the success of the simulations in modelling these behaviours. Such a comparison was also used to detect offsets in the beam centre position which can be caused by misalignments of the detectors or relative misalignments in magnet positions causing asymmetrical skew in the magnetic axis. These effects were quantified in this analysis. Particle identification combined with the earlier statistical analysis will be used to show that the number of muons required to meet the statistical requirements of MICE can be produced within a realistic time frame for each beam configuration considered.
10
Hyndman, Alexander. "Muon neutrino disappearance at T2K." Thesis, Queen Mary, University of London, 2012. http://qmro.qmul.ac.uk/xmlui/handle/123456789/2515.
Texte intégralRésumé :
This thesis measures the muon neutrino oscillation at T2K using the first data of the experiment. It concentrates on developing an original selection at Super-Kamionde, the T2K far detector, that improves the performance of the current standard selection. A new, more precise measurement of the oscillation parameters sin2 2 23 and Δm2 32 is performed using this new selection. T2K is a long-baseline neutrino oscillation experiment located in Japan which began data taking in January 2010. It uses the world’s most powerful accelerator generated beam of muon neutrinos intersected by two detectors. The near detector is located 280 m from the beam source while Super-Kamiokande lies 295 km away. Super-Kamiokande is a 50 kt water Cherenkov detector which measures the neutrino beam after oscillation. The determination of the oscillation parameters comes from looking at the disappearance of muon neutrinos from the beam. For this purpose event selection at Super-Kamiokande is optimised for neutrino flavour identification and energy reconstruction, specifically, selecting muon neutrino charged-current quasi-elastic events, primarily with single muon-like Cherenkov rings produced by the outgoing muon. This thesis evaluates two new methods of enhancing the selection to obtain a higher sensitivity from the data, firstly by exploring a multi-variate analysis approach to charged-current quasi-elastic selection, and secondly through the exploration of an additional charged-current single charged pion channel. Out of these only the multivariate based selection produced an improvement in the sensitivity to oscillation with respect to the standard selection. A first analysis of the data collected until March 11th 2011 using the above described improvement is presented in this thesis. A value of 2:68+0:12 −0:18 × 10−3 eV2 was recorded for Δm2 32 and 0:999+0:001 −0:009 for sin2 2 23. 2
11
Barker, Joel. "Muon studies of unconventional superconductors." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/105973/.
Texte intégralRésumé :
This thesis presents muon spin rotation and relaxation (μSR) studies of various superconducting materials. μSR studies have been complemented with laboratory measurements of heat capacity, resistivity, and magnetization. This work contributes to the body of work surrounding noncentrosymmetric superconductors (NCS) and unconventional superconductivity. The intermetallic compound La7Ir3 is found to break time-reversal symmetry upon transitioning into the superconducting state, elucidated by muon spin relaxation. The pairing symmetry appears fully gapped, and is well described by an isotropic s-wave model. Further theoretical analysis of the point group symmetry could investigate the allowed superconducting states potentially existing here. The physical properties of the NCS Re3Ta are well described by the conventional BCS theory of superconductivity. μSR suggests unusual narrowing of the vortex lattice signal in a region close to Tc, interpreted as motional narrowing due to thermal motion of vortices. This is supported by irreversible magnetization in a sizable region in the phase diagram. Ginzburg number and quantum resistance calculations place Re3Ta intermediate between the high-Tc and conventional low-Tc superconductors. LuRuB2 and YRuB2, superconducting members of the ternary boride family of materials, are studied using μSR. Zero-field measurements detect spin fluctuations exhibiting critical slowing down as the temperature is lowered, suggesting that these materials lie near a quantum phase transition. These weak fluctuations coexist with the superconductivity, which is well described by an isotropic, s-wave model for the pairing symmetry. The semi-metal Lu3Os4Ge13 is investigated using transverse-field and zerofield μSR. The superfluid density is well described by a model containing two superconducting gaps, supporting previously reported heat capacity measurements. Zero-field measurements below Tc reveal a signal hinting at broken time-reversal symmetry, however, it does not coincide with the bulk superconducting transition. Further theoretical work could determine whether this is the first observation of a novel three-gap multiband superconducting ground state.
12
Bandieramonte, Marilena. "Muon Portal project: Tracks reconstruction, automated object recognition and visualization techniques for muon tomography data analysis." Doctoral thesis, Università di Catania, 2015. http://hdl.handle.net/10761/3751.
Texte intégralRésumé :
The present Ph.D. thesis is contextualized within the Muon Portal project, a project dedicated to the creation of a tomograph for the control and scanning of containers at the border in order to reveal smuggled fissile material by means of the cosmic muons scattering. This work aims to extend and consolidate the research in the field of muon tomography in the context of applied physics. The main purpose of the thesis is to investigate new techniques for reconstruction of muon tracks within the detector and new approaches to the analysis of data from muon tomography for the automatic objects recognition and the 3D visualization, thus making possi- ble the realization of a tomography of the entire container. The research work was divided into different phases, described in this thesis document: from a prelimi- nary speculative study of the state of the art on the tracking issue and on the tracks reconstruction algorithms, to the study on the Muon Portal detector performance in the case of particle tracking at low and high multiplicity. A substantial part of the work was devoted to the study of different image reconstruction techniques based on the POCA algorithm (Point of Closest Approach) and the iterative EM-LM algorithm (Expectation-Maximization). In addition, more advanced methods for the tracks reconstruction and visualization, such as data-mining techniques and clustering algorithms have been the subject of the research and development ac- tivity which has culminated in the development of an unsupervised multiphase clustering algorithm (modified-Friends-of-Friends) for the muon tomography data analysis.
13
Woudstra, Martin Jacob. "Precision of the ATLAS muon spectrometer." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2002. http://dare.uva.nl/document/65010.
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14
Telling, M. T. F. "Muon studies of paramagnetic spin fluctuations." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387708.
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15
Serna, Alvaro. "Radiative muon capture on nuclear targets." Diss., Virginia Tech, 1991. http://hdl.handle.net/10919/39425.
Texte intégralRésumé :
A large acceptance pair spectrometer to detect photons from the radiative
muon capture (RMC) process was built. The spectrometer was used to measure
the RMC branching ratio for AI, Si, Ca, Mo, Sn and Pb. Two recent theoretical
models were used to extract the RMC branching ratio in Ca. The experin1ental
result is in good agreement with the world average value, but yields a value for
the pseudoscalar coupling constant, gp, which is lower than the Goldberger-Treiman
PCAC prediction. In the absence of a theoretical model to predict the R11C rates
for Al and 5i, only the branching ratios for these targets are reported. For Mo,
5n, and Pb, the branching ratios found were consistent with the Fermi gas n10del
for which a nill contribution from the pseudoscalar coupling was assumed. Good
agreement was found between the experimental results and what is predicted fron1
using the simple, closure approximation.
The RMC world data indicates a close connection between the branching ratios
and Q, where Q is the ratio between the difference and the sum of neutrons a.nd
protons for any element, (Q = ~Z~~J). It is suggested that future experiments study
different isotopes to isolate the Z and the Q dependence of the R11C rates.
This experiment also served as a test ground for the RMC experin1ent in liquid
hydrogen which is now in progress at TRIUMF.<br>Ph. D.
16
Henderson, C. G. L. "Simulation of muon-catalysed fusion experiments." Master's thesis, University of Cape Town, 1991. http://hdl.handle.net/11427/16010.
Texte intégralRésumé :
Includes bibliographical references.<br>A Monte Carlo code MUGLU has been, written for the simulation of experiments to measure alpha-muon sticking in muon catalysed deuterium-tritium fusion. The experiments simulated are those which measure the ratio of αμ to α from fusion in a low density gas target by detecting collinear alpha-neutron coincidences and relying on the differing stopping powers of the α and αμ ions. The Monte Carlo simulations provide estimates of geometrical and detection efficiency factors required for the calculation of the sticking coefficient from the experimental measurements. Simulations have been made of alternative experimental geometries in order to investigate the α-neutron coincidence signature and other characteristics of existing and proposed systems. The characteristics of a neutron detector used in, one of the current sticking experiments (Rutherford Appleton Laboratory) have been studied experimentally, as well as simulated, using the T(d,n)α reaction to emulate the fusion source. The results obtained show that the dependence of the neutron detection efficiency on the position and angle of neutron incidence on the detector is significant and should be taken into account when determining sticking coefficients from alpha-neutron coincidence measurements.
17
Mignot, Claude. "Pierre Le Muet, architecte (1591-1669)." Paris 4, 1991. http://www.theses.fr/1991PA040157.
Texte intégralRésumé :
Première monographie de l'oeuvre architecturale de Le Muet avec une chronologie complète de sa carrière et un catalogue raisonné de ses oeuvres. Issu d'une famille d'épée et de robe et non de la maîtrise,il mène une carrière d'ingénieur militaire et publie les modèles de sa Manière de bâtir avant de commencer vers 1637-38 une seconde carrière d'architecte. Il participe à l'évolution rapide,technique,distributive et esthétique de la construction privée autour de 1640. Formé dans le style maniériste tardif,il développe un classicisme atticiste moins sophistiqué,mais plus épuré que celui de Mansart. Complété par 3 chapitres "Le Muet :architectures de papier" traitant de son activité de théoricien<br>First monography of the architectural work of Le Muet with a compleat chronology and a catalogue of the books and buildings. .
18
Klasila, T. (Tarleena), and L. (Laura) Koivukangas. "”Se on mun työtapa ja se on mun filosofia, ja siellä on mun pedagogiikka”:opettajien kertomuksia positiivisen pedagogiikan toteuttamisesta." Master's thesis, University of Oulu, 2017. http://jultika.oulu.fi/Record/nbnfioulu-201711103091.
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Tiivistelmä. Tämän pro gradun tarkoituksena on kuvata narratiivisuuden keinoin luokanopettajien kertomuksia positiivisen pedagogiikan toteuttamisesta. Positiivinen pedagogiikka keskittyy oppilaan luonteenvahvuuksiin sekä voimavaroihin. Pedagogiikan pyrkimyksenä on ennaltaehkäistä ongelmia sekä parantaa yksilön oppimista ja hyvinvointia positiivisuuden kautta. Tutkielman tavoitteena on saada syvempi ymmärrys positiivisen pedagogiikan käytännön toteuttamisesta sekä löytää ideoita muille tästä opetus- ja kasvatussuuntauksesta kiinnostuneille. Tutkimuskysymyksenä on: 1. Mitä opettajat kertovat positiivisen pedagogiikan toteuttamisesta peruskoulussa?
Tutkimusaineisto on kerätty kolmelta positiivista pedagogiikkaa toteuttavalta peruskoulun opettajalta helmikuussa 2017. Aineisto koostuu kahdesta kerronnallisesta teemahaastattelusta sekä yhdestä kerronnallisesta kirjoitelmasta. Tutkimukseen osallistuneet opettajat olivat kattavasti perehtyneet positiiviseen pedagogiikkaan ja toteuttaneet sitä useamman vuoden ajan. Aineisto analysoitiin sisällönanalyysillä, jossa ensin aineisto redusoitiin eli pelkistettiin yksittäisiksi ilmaisuiksi, sen jälkeen klusteroitiin eli ilmaisut käsiteltiin ja ryhmiteltiin teemojen mukaan, ja viimeiseksi aineisto abstrahoitiin eli muodostettiin pääteemat.
Positiivisen pedagogiikan toteuttamisessa keskeiseksi nähtiin luonteenvahvuuksien etsiminen, ja niiden pedagoginen hyödyntäminen. Opettajat pitivät tärkeänä myös resilienssin vahvistamista, jonka he määrittelivät sisäisen puheen, onnistumisten, kasvun asenteen ja minäpystyvyyden kautta. Vuorovaikutuksen kehittämisen avulla opettajat rakensivat turvallista ilmapiiriä, joka lisäsi vahvuuksien kehittämistä ja harjoittelemista. Opettajat kuvasivat useita harjoitteita, joiden kautta näitä keskeisiä taitoja pystytään käytännössä harjoittelemaan. Vahvuuskielen käyttö sekä opettajan oma esimerkki nähtiin tärkeänä oppilaiden omaksuessa positiivista ajattelutapaa. Positiivista pedagogiikkaa opettajat toteuttivat integroiden sekä teematuntien, -päivien ja -viikkojen muodossa. Opettajat kokivat pedagogiikan toteuttamisen vahvistavan myös omaa opettajuutta ja hyvinvointia.
Luotettavuutta vahvistavia tekijöitä ovat tutkielmassa tutkijatriangulaatio sekä aineistotriangulaatio. Tutkielma pyrkii myös vahvistettavuuteen eli tehdyt ratkaisut avataan selkeästi lukijalle, jolloin pystytään arvioimaan tutkijoiden tekemää päättelyä. Tulokset eivät ole sellaisenaan yleistettävissä, vaan ne toimivat näkökulmana avaamassa positiivisen pedagogiikan käytännön toteuttamista. Narratiiviisessa tutkimuksessa on tärkeää, että tutkittavien kertomukset pääsevät kuuluviin. Jatkotutkimuksissa olisi tärkeää saada kattavampaa käytännön tietoa aiheesta. Erityisesti olisi mielenkiintoista tutkia positiivisen pedagogiikan vaikutuksia sosioekonomiseen asemaan sekä kiusaamisen ehkäisemiseen.
19
Lou, Kegang. "Direct measurement of the final-sticking probability in muon catalyzed dt fusion using the "Survived muon method" /." [S.l.] : [s.n.], 1993. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10410.
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20
Kenney, Christopher John. "A measurement of the decay rate for the process kaon(L) going to positive muon negative muon." W&M ScholarWorks, 1989. https://scholarworks.wm.edu/etd/1539623786.
Texte intégralRésumé :
A sample of 87 events of the GIM suppressed decay K$\sb{\rm L} \to \mu\sp+\mu\sp-$ were observed in an experiment performed in 1988 at the Brookhaven National Laboratory. Concurrently, 8,887 examples of the CP-violating decay K$\sb{\rm L} \to \pi\sp+\pi\sp-$ were also seen. The apparatus consisted of a double-magnet spectrometer as well as electromagnetic and muon detector systems. From the previously measured branching ratio for K$\sb{\rm L} \to \pi\sp+\pi\sp-$ and the different instrumental acceptances of the detector for the two decays, the data sample was normalized to the effective number of K$\sb{\rm L}$ decays observed. A value for the ratio (K$\sb{\rm L} \to \mu\sp+\mu\sp-)$/(K$\sb{\rm L} \to$ anything) of (5.7 $\pm$ 0.6(stat.) $\pm$ 0.3(syst.)) $\times$ 10$\sp{-9}$ was obtained.
21
Witkowski, Michael Thomas. "A measurement of the branching ratio of long-lived neutral kaon going to positive muon negative muon." W&M ScholarWorks, 1993. https://scholarworks.wm.edu/etd/1539623833.
Texte intégralRésumé :
The branching ratio $B(K\sbsp{L}{0} \to \mu\sp+\mu\sp-)$ has been measured using data obtained during running periods in 1988, 1989 and 1990. The data obtained in the 1990 running period are the latest and last from BNL experiment E791. During the three running periods, 87, 274 and 346 respective candidate events were observed, forming an overall sample of 707 $\mu\sp+\mu\sp-$ events. This number represents the largest sample to-date of $K\sbsp{L}{0} \to \mu\sp+\mu\sp-$ events. The result for the branching fraction using the total data set is $B(K\sbsp{L}{0} \to \mu\sp+\mu\sp-)$ = (6.86 $\pm$ 0.37) $\times$ 10$\sp{-9}$. This result is very near the unitarity bound of 6.81 $\times$ 10$\sp{-9}$ and is consistent with earlier measurements.
22
Musser, James Raymond. "Measurement of the Michel parameter rho in muon decay." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3297.
Texte intégralRésumé :
The TWIST Collaboration has measured the Michel parameter rho in normal muon
decay,u+ -> e+VeVu. In the standard model of particle physics,rho = 3/4. Deviations
from this value require mixing of left- and right-handed muon and electron couplings in
the muon-decay Lagrangian. We find rho = 0:75080+-0:00032(stat.)+-0:00097(syst.) +- 0:00023, where the last uncertainty represents the dependence of rho on the Michel
parameter n. This result sets new limits on the WL - WR mixing angle in left-right
symmetric models.
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Cicero, Valentina. "Development of the SHiP downstream muon detector." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19290/.
Texte intégralRésumé :
SHiP (Search for Hidden Particles) is a beam dump experiment proposed at CERN SPS, currently in the design stage. SHiP aims to observe long lived particles very weakly coupled with ordinary matter, as expected in a large number of Hidden Sector models, that are able do describe Dark matter, neutrino oscillation and the origins of the Barionic Asimmetry of universe.
In this thesis the development of the SHiP Downstream Muon Detector is described. This subdetector aims to identify with high efficiency muons produced by signal processes and to distinguish them from neutrino- and beam-induced background ones. In order to effectively distinguish background events mistakenly reconstructed as signal vertexes due to their spatial overlapping, a time resolution better than 200 ps is mandatory. Therefore, it is extremely important that the detector components are optimized with respect to time resolution.
The detector employs active layers made of plastic scintillator tiles, each coupled to silicon photomultipliers (SiPM). This thesis focuses on the development of tile prototypes that are able to meet the detector time resolution requirements, through the study of various aspects of the tile design.
The improved design defined with the contribution of this thesis work has become the current baseline design and will be tested with a prototype in early 2020 at the Frascati INFN Laboratories.
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Miyagawa, Paul Shinichi. "Muon energy calibration of the MINOS detectors." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409818.
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Brooks, Stephen J. "Muon capture schemes for the neutrino factory." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:7b724028-e4ef-4248-9d42-505e571c9e19.
Texte intégralRésumé :
The proposed neutrino factory, a facility for precision measurements of neutrino oscillations, requires directional neutrino beams to reach the required sensitivities. Among the few sources of such beams is the decay of muons travelling at relativistic speeds, therefore an intense source of muons and subsequent rapid acceleration must be designed so they can reach the required energy before decaying. This thesis considers several stages in this process: pions are produced from a proton beam hitting a target and pion yield optima are determined as a function of target design parameters and the proton energy. Issues related to producing the original proton beam are also discussed. The pions decay to a beam of muons, confined by a channel of solenoids and other components known as the muon front end. A design for this is found that meets the requirement of 10^21 muons per operational year [1]. The computer code MARS15 [2] is used to simulate the target, with benchmarks against GEANT4 [3] and initial results from the HARP experiment [4]. The author's code Muon1 [5] is used for muon tracking, with its techniques also explained in the thesis. To find the highest-yielding arrangement of magnets and accelerating components from the target onwards, Muon1 incorporates an optimisation feature where almost all parameters of the beamline can be varied. This produces a high-dimensionality search space where the best muon yield is sought using a genetic algorithm. As each individual evaluation of a design is itself a time-consuming simulation with tens of thousands of particles, the code has been deployed as a distributed computing project that is able to perform millions of simulations per optimisation. [1] "GROUP REPORT: Physics at a Neutrino Factory", C. Albright et al. (Eds. S. Geer and H. Schellman), Report to the Fermilab Directorate, FERMILAB-FN-692, hep-ex/0008064 (2000). [2] "The MARS Code System" version 15.07, by N.V. Mokhov, available from http://www-ap.fnal.gov/MARS/ [3] "GEANT4 - a simulation toolkit", S. Agostinelli et al., Nuclear Instruments and Methods A 506, pp.250-303 (2003), available from http://geant4.web.cern.ch/geant4/ [4] "Status and prospects of the HARP experiment", M. Ellis, J. Phys. G 29, pp.1613-1620 (2003). [5] Muon1 Distributed Particle Accelerator Design project website, http://stephenbrooks.org/muon1
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Steele, Andrew J. "Quantum magnetism probed with muon-spin relaxation." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:030d7e91-f38e-433f-9539-652b0f4996cc.
Texte intégralRésumé :
This thesis presents the results of muon-spin relaxation (µ<sup>+</sup><abbr>SR</abbr>) studies into magnetic materials, and demonstrates how these results can be exploited to quantify the materials’ low moments and reduced dimensionality. Dipole-field simulations, traditionally used to estimate likely muon sites within a crystal structure, are described. A novel Bayesian approach is introduced which allows bounds to be extracted on magnetic moment sizes and magnetic structures—previously very difficult using µ<sup>+</sup><abbr>SR</abbr>—based on reasonable assumptions about positions in which muons are likely to stop. The simulations are introduced along with relevant theory, and MµCalc, a platform-independent program which I have developed for performing the calculations is described. The magnetic ground states of the isostructural double perovskites Ba<sub>2</sub>NaOsO<sub>6</sub> and Ba<sub>2</sub>LiOsO<sub>6</sub> are investigated with µ<sup>+</sup><abbr>SR</abbr>. In Ba<sub>2</sub>NaOsO<sub>6</sub> long-range magnetic order is detected via the onset of a spontaneous muon-spin precession signal below <var>T</var><sub>c</sub> = 7.2(2) K, while in Ba<sub>2</sub>LiOsO<sub>6</sub> a static but spatially-disordered internal field is found below 8 K. Bayesian analysis is used to show that the magnetic ground state in Ba<sub>2</sub>NaOsO<sub>6</sub> is most likely to be low-moment (˜ 0.2<var>µ</var><sub>B</sub>) ferromagnetism and not canted antiferromagnetism. Ba<sub>2</sub>LiOsO<sub>6</sub> is antiferromagnetic and a spin-flop transition is found at 5.5 T. A reduced osmium moment is common to both compounds, probably arising from a combination of spin–orbit coupling and frustration. Results are also presented from µ<sup>+</sup><abbr>SR</abbr> investigations concerning magnetic ordering in several families of layered, quasi–two-dimensional molecular antiferromagnets based on transition metal ions such as <var>S</var> = ½ Cu<sup>2+</sup> bridged with organic ligands such as pyrazine. µ<sup>+</sup><abbr>SR</abbr> allows us to identify ordering temperatures and study the critical behaviour close to <var>T</var><sub>N</sub> , which is difficult using conventional probes. Combining this with measurements of in-plane magnetic exchange <var>J</var> and predictions from quantum Monte Carlo simulations allows assessment of the degree of isolation of the 2D layers through estimates of the effective inter-layer exchange coupling and in-layer correlation lengths at <var>T</var><sub>N</sub>. Likely metal-ion moment sizes and muon stopping sites in these materials are identified, based on probabilistic analysis of dipole-fields and of muon–fluorine dipole–dipole coupling in fluorinated materials.
27
Battu, Sivaram Kumar. "Data Acquisition System for Muon Lifetime Experiment." UKnowledge, 2006. http://uknowledge.uky.edu/gradschool_theses/230.
Texte intégralRésumé :
I designed, developed and deployed a data acquisition (DAQ) system to meet the needsof the "??Lan" nuclear physics experiment. The main goal of the experiment is to measurethe positive muon lifetime to a precision of 1 part per million. This represents more thanan order of magnitude increase in precision beyond the current world average. The DAQdesign is motivated by very high data rate this experiment will produce. This experimentis being performed with the proton accelerator at Paul Scherrer Institut in Villigen,Switzerland. I have setup a mock experimental setup at the University of Kentucky. Thedesign and development of the DAQ software was conducted using this mock setup andwas deployed at Paul Scherrer Institut in the fall 2005.
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Aston, Georgina Margaret. "Molecular dynamics with muon spin relaxation/rotation." Thesis, University of East Anglia, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338062.
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Hubbard, Penny Louise. "Molecular and electron dynamics with muon spectroscopy." Thesis, University of East Anglia, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268573.
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Devenish, Nicholas. "Muon antineutrino disappearance in the MINOS experiment." Thesis, University of Sussex, 2015. http://sro.sussex.ac.uk/id/eprint/58686/.
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Lundkvist, Jakob. "Muren : Ett nytt krematorium på Norra Begravningsplatsen." Thesis, KTH, Arkitektur, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-172338.
Texte intégralRésumé :
Krematoriets struktur bygger på två murar. Den ena bildar en ny gräns mot norra begravningsplatsen och den andra leder besökaren ner för backen och in i krematoriet. Själva gränsen mot norra begravningsplatsen är på just denna plats inte alls lika omhändertagen som runt resten av begravningsplatsen, och viljan att ge inte bara själva krematoriet utan även omgivningarna goda kvalitéer har varit en av de viktigaste parametrarna vid gestaltningen. Krematoriet med dess murar ger platsen en tydlighet, för anhöriga, personalen och för förbipasserande. På kullen vid murens startpunkt skapas en ny entré till norra begravningsplatsen. Själva krematoriet ligger delvis under den gång/cykelväg som sträcker sig längs begravningsplatsens västra gräns. För att krematoriet inte ska skapa en tråkig baksida mot befintlig gång/cykelbana dras den på krematoriets tak. På detta sätt integreras krematoriet i landskapet och ger mer plats för en större omgivande park. Murarna kläs i stenskivor av granit. Graniten på den övre muren har en grövre yta tänkt att smälta samman med landskapet. Graniten på den nedre muren har en polerad yta som reflekterar omgivningarna och den mer bearbetade ytan gör att muren läses ihop med själva byggnaden snarare än med landskapet. För de anhöriga blir denna nedre mur ett sätt att orientera sig i byggnaden då den är exponerad i alla rum som de anhöriga besöker. Som anhörig besökare följer man muren från begravningsplatsens entré söderut ner för slänten. Muren är helt horisontell och blir högre ju längre ner för backen man kommer. Entrén utgörs av en utskjutande volym och innanför finns de rum som är avsedda för de anhöriga. Slutligen omsluter muren anhörigrummet där urnutlämningen sker, och bilar där ett rum med interiör del kopplad till en exteriör gård. Ett träd med en omgivande vattenspegel upptar större delen av denna inre gård. Trädet filtrerar solljuset och ger ett skuggspel över väggar och golv och vattenspegeln reflekterar solljuset och ger ett ljusspel mot muren på gården. Avsikten är att skapa ett tydligt avgränsat rum där naturen ändå är närvarande och ger liv åt materialen. För att skapa en god arbetsmiljö på krematoriet ordnas rummen för att logiskt passa in i processen från kistans mottagning till att urnan hämtas. Pausrum och arbetsrum finns i den södra delen i nära anslutning till kistmottagningen. De rumsliga sambanden är också avsedda att skapa möjlighet för sociala möten mellan personalen och även med begravningsentreprenörerna.<br>The structural principle of the crematory is based on two walls. The first creates a new border to the northern cementary. The second wall leads the visitor down the hill and in through the crematory. The actual border of the cementary is at the projects site not as well taken cared of as on the rest of the cementary, and a will to give not only the crematory but also the surroundings good qualities has been one of the most important parameters during the project. The crematory and its walls gives the site clarity and simplicity for the relatives, the employees and also for bypassers. On the hill at the starting point of the wall, a new entrance to the cementary is created. The crematory is partly situated under the pedestrian/bicycle path ranging along the cementarys western border. To prevent the crematory from turning its back on the existent destrian/bicycle path, that very path is given a new route on the rooftop of the crematory complex. In this way, the crematory naturaly integrates itself in the surrounding landscape and saves alot of space for the surrounding park. The walls have a granite facade, on the upper wall with a rough surface intended to blend into nature and on the lower wall with a polished surface to connect it to the crematory building rather than the landscape. Beeing exposed in every room intended to be visited by relatives to the deceased, this lower wall is a way for them to orient themselves during their visit. As a visitor you follow the wall from the cementary entrance, going south down a sligt hill the wall is getting higher as you move towards the main entrance to the crematory, which is a volume protruding from the lower wall. The spaces intended for the relatives are located close to the main entrance, and the most important of those rooms is the room where the relatives collect the urn. In that rectangular room, which has an exterior and an interior space closely connected, you are surrounded by the lower wall on all sides. The exterior space a tree stands surrounded by a pond, whose reflections and shadows give life to the materials. To create a good environment for the employees, the rooms have been organized to fit the crematory process, from the recievement of the chest to handing over the urn. Paus- and officespaces are located in the south part of the building, closley connected to the chest recievement room. The connections between the crematorys different rooms are intended to create spontaneus meetings between the employees, and also with the visiting funeral directors.
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Parzyk, Natalia A. "Muon and neutron studies of unconventional superconductors." Thesis, University of Warwick, 2014. http://wrap.warwick.ac.uk/67561/.
Texte intégralRésumé :
The mechanism of unconventional superconductivity is still mysterious, despite extensive studies. Muon spectroscopy (μSR) and small angle neutron scattering (SANS) studies of some unconventional superconductors were carried out. The NCS superconductors: Ru7B3 and α-BiPd, Heusler compounds: ZrNi2Ga and NbNi2Ga and the marginal superconductor ZrB12 were investigated. This thesis reports new phenomena observed in those systems and advances the knowledge of the ground state properties of unconventional superconductors. Polycrystalline samples and single crystals of the non-centrosymmetric superconductor (NCS) Ru7B3 were studied. Evidence for time-reversal symmetry (TRS) breaking in the superconducting state of Ru7B3 were found using μSR. So far, it is the third known NCS superconductor which breaks TRS. Potentially multigap behaviour was observed. The presence of two distinct superconducting gaps was suggested in polycrystalline Ru7B3 using μSR. Additionally, SANS and μSR measurements indicate unusual behaviour for the observed distorted hexagonal flux line lattice (FLL) in Ru7B3, yet the nature of this behaviour remains inconclusive. μSR studies of another NCS superconductor α-BiPd give evidence that two superconducting gaps are present in α-BiPd, either two s-wave gaps or s-wave and d-wave gaps exist in α-BiPd. Additionally, unusual temperature evolution of the upper critical field of α-BiPd was observed. Two superconducting compounds belonging to the Heusler family, ZrNi2Ga and NbNi2Ga, were investigated using μSR. Temperature dependence of the penetration depth of ZrNi2Ga suggests an s-wave, conventional behaviour in this superconductor. Evidence of a structural change in the morphology of the FLL was observed: a square FLL potentially exists at low temperatures and a hexagonal FLL is present closer to Tc. Additionally, μSR experiments suggest that TRS is preserved in both measured Heusler compounds. SANS studies of a marginal, low-k superconductor ZrB12 were carried out. SANS studies were performed in a range of temperature and magnetic field so to access different parts of the superconducting phase diagram of ZrB12. A square vortex lattice was found in all measured temperatures and fields.
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Tsikounas, Myriam. "Représentations d'une société : le cinéma muet soviétique." Paris 8, 1990. http://www.theses.fr/1991PA080544.
Texte intégralRésumé :
Un corpus de soixante-dis-neuf films muets sovietiques a ete reconstitue et etudie sous deux angles differents, thematique et structurel, dans le but d'atteindre les representations qui se font jour dans la russie post-revolutionnaire et d'en suivre l'evolution sur une "moyenne duree" (1918-1935). -la premiere enquete, qui traite les films comme une masse documentaire, a permis de voir comment les professionnels du spetacle apprehendaient leur societe et comprennaient l'evolution qui avait mene de nicolas 1er a staline. -la seconde exploration, qui prend en compte la specificite du langage filmique, a donne les moyens de determiner l'originalite de ce cinema et a revele la coexistence de deux series filmiques tres differentes: les produits mineurs, qui evoquent les difficultes de la vie quotidienne sous la n. E. P. Et les oeuvres phares, esthetiquement parfaites, qui commemorent la revolution pour la transformer en objet mythique<br>A reconstructed corpus of 79 soviet silent films is examined from two viewpoints -thematic and structural- with the aim of eliciting the representa- tions that came to light in post-revolutionary russia and their subsequent evolution during the period 1918-1935. The first approach, taking the films as a documentary source, enabled to see how professional entertainers apprehended their society and understood its evo- lution from nicholas i to stalin. The second, accounting for the specificity of filmic language, enabled to assess the originality of this cinema and revealed the coexistence of two very different series: minor productions evoking the difficulties of everyday life under the n. E. P. And "beacon" films, esthetically perfect, wich commemorated the revolution in order to transform it into a mythical object
34
Thomay, Christian. "Muon scattering tomography for nuclear security applications." Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683733.
Texte intégralRésumé :
The threat of illicit trafficking of special nuclear material (SNM) has brought about an interest in detection methods capable of identifying high-Z material in a non-invasive fashion on relatively short timescales. Muon Scattering Tomography (MST) is a method by which information about the material content of a cargo container can be obtained by measuring cosmic ray muons before and after passing through the container. In this way significant quantities of SNM that are being illegally shipped at freight ports can be detected. In a real-life application, it is important for practical reasons that containers carrying SNM can be identified swiftly, on a time scale of minutes. MST requires large detectors above and below the volume of interest. Resistive plate chambers (RP Cs ) were chosen for this, which have good spatial and timing resolution, good hit finding efficiency, and can be produced on large scales. RPC prototypes were built, and the performance of these RPCs is detailed, together with the software framework developed for the analysis of the detector data. Two novel detection algorithms were developed, intended to find SNM hidden in cargo containers. In order to test the algorithms, a simulation study with large-scale detectors tuned to the performance of the RPCs was performed. A wide range of cargo was simulated in this study based on real-life cargo data, showing the performance of the new algorithms in terms of the fraction of containers can be cleared in a given time frame. It is shown that 84% of all containers can be cleared in a minute or less, showing that the methods meet the design goals. An application of the developed methods to 3D imaging of legacy nuclear waste drums is also shown. Here, longer scan times are possible, and dimensions on the order of centimeters can be resolved inside concrete-filled waste drums.
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Viel, David William. "Muon transfer from muonic deuterium to carbon." W&M ScholarWorks, 1994. https://scholarworks.wm.edu/etd/1539623853.
Texte intégralRésumé :
Negative muons were brought to rest in a gas mixture of 30 torr CH$\sb4$ and 570 torr D$\sb2$, using the cyclotron trap at PSI. The muons formed muonic deuterium atoms which diffused through the mixture and transferred their muons to the carbon of the CH$\sb4$ molecules. A planar germanium detector and a silicon detector were used to observe x-rays from the initial muon cascade in the deuterium, and from subsequent cascade in the muonic carbon after transfer. A transfer rate of (4.5 $\pm$ 1.8) $\times$ 10$\sp{10}$/sec was found which agrees well with a previous result measured at 50 bar of (5.1 $\pm$ 1.0) $\times$ 10$\sp{10}$/sec. Transfer was found to occur predominantly to the n = 4 state in $\mu$C. The initial angular momentum state distribution in the $\mu$C was constructed using the cascade program of V. Markushin, and found to be consistent with any combination of two possible initial distributions (I 0.252 (4s) + 0.409 (4f) + 0.339 (4p)) and (II 0.284 (4d)+ 0.377 (4f) + 0.339 (4p)). The transfer theories of Gershtein and that of Holtzwarth and Pfeifer both agree well with the measured transfer rate and initial energy state, but not with the initial angular momentum distributions. The 2S population in $\mu$C was also determined to lie between 5% and 11%, which is higher than the 3% population in direct capture.
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Suzuki, Kento. "Measurement of the Muon Beam Properties and Muon Neutrino Inclusive Charged-Current Cross Section in an Accelerator-produced Neutrino Experiment." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/200485.
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Geddes, N. I. "Properties of jet fragmentation in deep inelastic mup scattering at 280 GeV/c." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370319.
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Guarnaccia, Evan Thomas. "Modeling and Measurement of the Cosmic Muon Flux at Underground Sites." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/49664.
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Marks, Martin Miller. "Music and the silent film : contexts and case studies, 1895-1924 /." New-York ; Oxford : Oxford university press, 1997. http://catalogue.bnf.fr/ark:/12148/cb36988683h.
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Girotti, Paolo. "Simulazione Monte Carlo del muon veto dell'esperimento XENON1T." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/12022/.
Texte intégralRésumé :
Numerose osservazioni astrofisiche e cosmologiche compiute a partire dagli anni '30 confermano che circa il 26% dell'Universo è costituito da materia oscura. Tale materia ha la particolarità di interagire solo gravitazionalmente e, forse, debolmente: essa si presenta massiva e neutra. Tra le numerose ipotesi avanzate riguardanti la natura della materia oscura una delle più accreditate è quella delle WIMP (Weakly Interacting Massive Particle).
Il progetto all'avanguardia nella ricerca diretta delle WIMP è XENON presso i Laboratori Nazionali del Gran Sasso (LNGS). Tale esperimento è basato sulla diffusione elastica delle particelle ricercate su nuclei di Xeno: il rivelatore utilizzato è una TPC a doppia fase (liquido-gas). La rivelazione diretta di materia oscura prevede l'impiego di un rivelatore molto grande, a causa della piccola probabilità di interazione, e di ambienti a bassa radioattività naturale, per ridurre al minimo il rumore di fondo.
Risulta necessario inoltre l'utilizzo di uno schermo attivo che individui particelle di alta energia, in particolare muoni cosmici, che possono produrre falsi segnali. È stato realizzato a tale scopo un sistema di Muon Veto composto da un grande cilindro d'acqua posto attorno alla TPC, equipaggiato con 84 fotorivelatori atti ad osservare i fotoni ottici emessi per effetto Čherenkov dai raggi cosmici.
Il presente lavoro di tesi si colloca nell'ambito di un programma di simulazione Monte Carlo, creato per realizzare virtualmente l'esperimento XENON1T e per effettuare studi preliminari. Lo scopo di tale lavoro è stato quello di contribuire alla scrittura e alla verifica del codice di simulazione e allo studio di eventi di muoni cosmici da esso generati.
L'analisi dati è stata effettuata scrivendo un programma in C++ in grado di analizzare i risultati forniti dal simulatore e di generare degli Event Display statici e dinamici per una visualizzazione efficace degli eventi.
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Musumeci, Emanuela. "Heavy Majorana neutrinos at a future muon collider." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
Trouver le texte intégralRésumé :
In this thesis work we have explored the production of heavy Majorana neutrinos at a future muon collider. At variance with the Standard Model which predicts neutrinos to be massless, the observation of neutrino oscillations implies that they are massive particles. This has opened a new era in particle physics, where the origin of neutrino masses and their nature, Dirac or Majorana, are being explored. The Majorana nature of neutrinos can be experimentally probed only via lepton-number violating processes involving charged leptons. We have focused our attention on the production of a heavy neutrino at multi-TeV hadron and lepton colliders (specifically at a muon collider). We have considered the vector boson fusion channel W+W+ → l+l′+, mediated by Majorana neutrinos and verified the unitarity properties of this process in a Type I See-Saw. We have then studied same-sign lepton pair production, at both hadron and lepton machines in simplified Heavy Neutrino models, showing that the latter have the potential to either discover or constrain the existence of heavy Majorana neutrinos.
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Hiraki, Takahiro. "Muon Antineutrino Disappearance Measurement by the T2K Experiment." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215313.
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Virtue, Clarence John. "Photon asymmetry in radiative muon capture on calcium." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/27558.
Texte intégralRésumé :
The photon asymmetry (⍺⋎) and partial branching ratio (Rk>57), for radiative muon capture on ⁴⁰Ca, have been measured in order to determine the magnitude of the induced-pseudoscalar coupling constant, gp. A large Nal(Tl) crystal (46cm ϕ x 51cm) was used with an active Nal(Tl) converter (36cm x 30cm x 5cm) as the photon detector. The combined system had an energy resolution of 15% at 70 MeV; a factor of two improvement over previous similar experiments.
Simultaneous measurements of the photon asymmetry and the partial branching ratio have been performed twice in the past. From a theoretical stand-point the photon asymmetry measurement is of greater interest as it represents the least nuclear model-dependent way of extracting gp. In the present experiment we have observed 3100 photons with energies greater than 57 MeV, after background subtraction. Of these, 2500 could be used in the determination of ⍺⋎. A value of ⍺⋎ = 1.32+⁺⁰֗⁵⁴˗₀․₄₇ is obtained from a fit to the photon time distribution.
For the first time in such measurements the photon asymmetry was visible in the time spectrum and an unconstrained fit is able to reproduce its known frequency and phase. The extracted asymmetry allows for the first time a meaningful limit to be placed on gp which is free of the uncertainties associated with the extraction of gp from the partial branching ratio. Our asymmetry result implies gp < 5Agp, favouring a renormalization of the induced-pseudoscalar coupling constant. The partial branching ratio determined in this experiment is consistent with previous measurements. A model-dependent extraction of gp from Rk>57 yields gP ~ (7 ± 2)gA. As a consequence of this work an improved experiment has recently been successfully performed at TRIUMF with increased statistics, improved energy resolution, and an improvement of approximately a factor of 15 in the signal-to-noise ratio.
We have also identified a potential systematic error of as large as 15% in the normalization of the photon asymmetry in past experiments. Such an error occurs from the use of the V—A asymmetry distribution rather than a bound decay asymmetry distribution when performing Monte Carlo calculations of the decay electron asymmetry. This error affects the estimation of the residual muon polarization which is used to normalize the photon asymmetry.<br>Science, Faculty of<br>Physics and Astronomy, Department of<br>Graduate
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Armstrong, David Stairs. "Radiative muon capture on carbon, oxygen and calcium." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/29004.
Texte intégralRésumé :
The partial branching ratio for photons of greater than 57 MeV (G[sub >57]) has been measured for radiative muon capture (RMC) on ¹²C, ¹⁶O and ⁴⁰Ca in order to determine the magnitude of the induced pseudoscalar coupling constant g[sub p] of the weak hadronic current. A time projection chamber (TPC) was used as a large solid-angle, medium-resolution pair spectrometer to detect the photons from RMC. The resulting spectra were essentially background-free, allowing a determination of the partial branching ratios to about 10% precision.
For ⁴⁰Ca, the partial branching ratio obtained is in good agreement with previous measurements, and yields the value g[sub p]/g[sub a] = 5.7 ± 0.8 when compared with a phenomenological calculation of the nuclear response function and the value g[sub p]/g[sub a] = 4.6 ± 1.8 when compared with a microscopic calculation of the nuclear response function. Both of these results suggest a slight (downward) renormalization of g[sub p]/g[sub a] in ⁴⁰Ca in comparison with the value expected for a free nucleoli.
For ¹⁶O, the partial branching ratio obtained in the present experiment is found to disagree strongly with one previous experiment but to agree with the second previous measurement. When compared with a phenomenological calculation of the nuclear response our result yields g[sub p]/g[sub a] = 7.3 ± 0.9, consistent with an un-renormalized value of g[sub p]. The same results compared to a microscopic calculation give the value g[sub p]/g[sub a] = 13.6 [sup +1.6]/[sub -1.9] suggesting a large (upward) renormalization of g[sub p] in the ¹⁶O nucleus.
The first precise branching ratio has also been measured for RMC on ¹²C. No calculation of the nuclear response specific to ¹²C is available at present. However, when the present data are compared with a naive extrapolation of Fermi-gas model calculations of the nuclear response for heavier nuclei, the brandling ratio is found to be consistent with an unrenormalized value of g[sub p].
The present work has also provided valuable input, through the investigation of various systematic errors and potential backgrounds, into the design of a detection system for a forthcoming measurement of RMC on hydrogen.<br>Science, Faculty of<br>Physics and Astronomy, Department of<br>Graduate
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Sobratee, Farhana. "M11 channel at TRIUMF, another surface muon source." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ60188.pdf.
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Tyler, Jonathan. "Muon identification with Veritas using the Hough Transform." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107695.
Texte intégralRésumé :
Imaging atmospheric Cherenkov telescope (IACT) arrays such as VERITAS are used to perform very high-energy gamma-ray astronomy. This is accomplished by detecting and analyzing the Cherenkov light produced by gamma-ray initiated atmospheric air showers. IACTs also detect the Cherenkov light produced by individual muons. The Cherenkov light produced by muons is well understood, and can be used as a calibrated light source for the telescopes. Muons create characteristic annular patterns in the cameras of IACTs, which may be identified using parametrization algorithms. One such algorithm, the Hough transform, has been used to identify muons in VERITAS data. The details of the Hough transform and its implementation on VERITAS data will be described, as well as the use of parameters derived from the Hough transform for muon identification. In addition, the selection of muon rings appropriate for calibration purposes will be described. Finally, the Hough transform-based muon selection technique will be compared to the standard VERITAS muon selection technique.<br>Les systèmes de télescopes par imagerie Cherenkov tel que VERITAS sont utilisés pour l'astronomie à rayons gammas de très hautes énergies. Ceci est accompli par la détection et l'analyse de la lumière Cherenkov produite par les gerbes de particules causées par l'interaction des rayons gammas avec l'atmosphère. Ces télescopes détectent aussi la lumière Cherenkov produite par les muons. La lumière Cherenkov produite par les muons est bien comprise, et peut être utilisée comme source de calibration pour les télescopes. Les muons forment un anneau dans leur caméra, et peuvent être identifiés en utilisant des algorithmes de paramétrisation. La transformée de Hough est un de ces algorithmes, et a été utilisé afin d'identifier les muons dans les données de VERITAS. Les détails de la transformée de Hough et son application avec VERITAS seront présentés, ainsi que l'utilisation des paramêtres en découlant pour l'identification de muons. De plus, la sélection d'anneaux de muons appropriés pour des besoins de calibration sera décrite. Finalement, la technique de sélection de muons basé sur les transformées de Hough sera comparée à la technique de sélection de muons standard de VERITAS.
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Jestadt, Thomas. "Muon studies of low-dimensional solid state systems." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301173.
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Steer, Christopher. "Muon studies of colossal magnetoresistive and related compounds." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414274.
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Brooks, Michael. "Muon-spin rotation studies of correlated inorganic systems." Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443599.
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Lewtas, Heather Joanne. "A muon and neutron study of multiferric materials." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.556212.
Texte intégralRésumé :
In this thesis multiferroic materials are investigated through a number of different experimental techniques, particularly p,+SR, neutron scattering and impedance spec- troscopy. The magnetic and dielectric properties of materials, which form multiferroic states through different mechanisms, are explored. Inelastic neutron scattering studies have been made of LuMn03 and LuFe204. Large reciprocal space maps have been made of LuFe204 and an initial spin wave dispersion found. The exchange parameters have been estimated from the data and are shown to support ab initio calculations. The spin wave dispersion of LuMn03 has been mapped throughout the Brillouin zone and the exchange parameters extracted by comparison with a spin-wave model. Com- parisons have then been made with other members of the hexagonal manganite family. The analysis is supported by thermal expansion and magnetization studies. The first experiment on a multiferroic combining the p,+SR technique and applied electric fields was performed as a proof of principle experiment on HoMn03. The effect of the elec- tric field on the magnetism has been detected and calculations performed to try and identify muon stopping sites. The family of rare earth chromites have been studied through magnetization and heat capacity experiments as well as p,+SR. The vary- ing entropy and energy level splitting within the family is examined and the debate as to whether they are multiferroic is addressed. An instrument to study dielectric properties at cryogenic temperatures through impedance spectroscopy was designed and constructed. Multiferroics investigated in this thesis using neutron scattering and p,+SR were then studied with this apparatus to look for coupling between magnetic and ferroelectric order parameters. A dielectric anomaly associated with the magnetic transition temperature was observed in LuFe204 which is evidence of the coupling between the order parameters.