1,722 research outputs found
La Pomme D'Eris, Ou Le Combat Des Deesses, en vers Burlesques, À l'imitation du Combat des Muses & des Parques, ou de la Gigantomachie du Sieur Scarron : Composé à l'occasion des Nôces de Monsieur Jean Louys Frey, & de Mademoiselle Marie Magdaleine Gernler / Par leur tres-humble Serviteur, J. B.
No full textA New Interaction Region Design for the Super-B Factory
No full textA final focus magnet design that uses super-ferric magnets is introduced for the SuperB interaction region. The baseline design has air-core super-conducting quadrupoles. This idea instead uses super-conducting wire in an iron yoke. The iron is in the shape of a Panofsky quadrupole and this allows two quadrupoles to be sideby- side with no intervening iron as long as the gradients of the two quads are equal. This feature allows us to move in as close as possible to the collision point and minimize the beta functions in the interaction region. The superferric design has advantages as well as drawbacks and we will discuss these in the pap
Uso de FMEA na melhoria da durabilidade de um acoplamento mecânico aplicado em motor de partida
No full textTCC (graduação) - Universidade Federal de Santa Catarina. Campus Joinville. Engenharia Automotiva.Diante do cenário competitivo da indústria automotiva no Brasil e no mundo, a confiabilidade dos produtos é um dos fatores determinantes no sucesso dos mesmos. A Zen S.A. Indústria Metalúrgica está inserida neste mercado com amplo portfólio de impulsores de partida, acoplamentos mecânicos, tensionadores e polias, voltados para o mercado de reposição de peças como também para montadoras de veículos. Este trabalho trata de um projeto de melhoria de desempenho em durabilidade de um acoplamento mecânico específico, aplicado em motores de partida para automóveis da linha pesada, como motores MWM, Cummins dentre outros. Este acoplamento teve sua venda temporariamente bloqueada devido reclamações frequentes de clientes, os quais alegavam falha prematura do produto. Será apresentado todo o processo de aplicação de um FMEA voltado para geração de soluções técnicas para o produto e para o sistema de qualidade referente a este, de maneira que os eventuais custos na alteração do projeto sejam justificados por métodos científicos consistentes. O FMEA é o método mais utilizado na indústria automotiva para este fim (AIAG, 2011), uma vez que é voltada para a identificação das causas específicas de falhas, fornecendo base para ação na redução da ocorrência e severidade das mesmas e melhorando os mecanismos de detecção (BERTSCHE, 2008). Com a aplicação deste FMEA foi possível, na prática, alterar alguns parâmetros de projeto dos componentes do acoplamento mecânico, que teve seu desempenho em durabilidade mensurado em teste de bancada
Measurement of the Top Quark Pole Mass and QCD Radiation in Top Quark Pair Production using Electron-Muon Events with b-Tagged Jets in Proton-Proton Collisions at 7-8 TeV with the ATLAS Detector at the LHC
No full textAs heavy as an atom of gold but much smaller than a proton, the top quark is the most massive fundamental particle known in the universe and an integral part of current particle physics research. The characteristics of the top quark, such as its high mass—close to the scale of electroweak symmetry breaking—and its dominance in the running of the recently discovered Higgs boson’s self-coupling, make the top quark a cornerstone of current research. Studies of the top quark are probes of new physics, essential tools to understand the Higgs boson, and valuable tests of the Standard Model. This thesis presents two measurements of top quark pair production events collected with the ATLAS Detector at the CERN Large Hadron Collider (LHC) in proton-proton collisions at a center-of-mass energy 7-8 TeV. Both measurements select top-antitop quark events with an opposite-sign electron-muon pair and one or two b-tagged jets in the final state.
A study is first presented of the jet activity arising from quark and gluon radiation produced in association with top quark pairs, in events with an opposite-sign electron-muon pair as well as at least two b-tagged jets in the final state. It includes the complete 2012 ATLAS data sample of 20.3 fb-1 integrated luminosity of proton-proton collision data at 8 TeV. The fraction of events that does not contain additional jet activity in a central rapidity region is measured as a function of a) the minimum transverse momentum of any additional jet in the event, and b) the minimum scalar transverse momentum sum of all additional jets in the event, and the results given for four central rapidity regions and four regions of the invariant mass of the electron, muon and two b-jet system. Compensation for detector effects is applied to the experimental measurement and the results compared at the particle level to simulations by several next-to-leading order (NLO) and leading order (LO) Monte Carlo generators. The resulting gap fraction measurements, in comparison with simulation, can be used to tune Monte Carlo modeling of quantum chromodynamic (QCD) radiation and reduce associated modeling uncertainties in ATLAS physics measurements involving top quark pair production, such as top quark measurements and Higgs boson measurements with top quark backgrounds.
Secondly, the top quark pole mass (mpole) was extracted from top quark pair top events having an opposite-sign electron-muon pair in the final state and one or two b-tagged jets. This measurement includes the complete 2012 ATLAS data sample, as well as the complete 2011 ATLAS data sample of 4.6 fb-1 integrated luminosity of proton-proton collision data at 7 TeV. This is combined with the theoretical cross section prediction including QCD corrections at next-to-next-to-leading order (NNLO+NNLL), with three different sets of parton distribution functions. The results are:
top quark pole mass (7 TeV) = 171.40+2.58-2.56 GeV
top quark pole mass (8 TeV) = 174.10 ± 2.64 GeV
top quark pole mass (7-8 TeV) = 172.87+2.51-2.63 GeV
in which the uncertainties include data statistics, experimental systematic effects, the knowledge of integrated luminosity and LHC beam energy, as well as PDF, QCD scale, and strong coupling constant uncertainties. An examination of consistency between the 7 and 8 TeV results found agreement within approximately 1.6 sigma
Determining Time Saving Factors in Gearbox Testing
No full textDie Entwicklung neuer Automobilgenerationen ist konfrontiert mit der Verkürzung der Markteinführungszyklen, gesteigertem Kostendruck bei gleichzeitiger Steigerung der Qualität. Ein Ansatz, diesen Konflikt zu lösen, ist die aufwendige und zeitintensive Fahrerprobung der Fahrzeuge zu verkürzen. Es wird angestrebt, zeitlich geraffte Versuche durch die Variation verschiedener Parameter durchzuführen. Die Schwierigkeit besteht darin, die Parameter so zu bestimmen, dass die Schädigung in der Erprobung mit der im realen Einsatz übereinstimmt. Der Einsatz von Simulationswerkzeugen bietet hier die Möglichkeit, die Auswahl der zu variierenden Parameter auf das zu prüfende Fahrzeug abzustimmen, und so im Vorfeld der Erprobung das Raffungspotential zu ermitteln.
Die am Institut für Maschinenelemente (IMA) der Universität Stuttgart entwickelte Simulationsumgebung bietet die Möglichkeit, beliebig aufgebaute Triebstränge auf gemessenen oder synthetischen Fahrstrecken hinsichtlich Belastungen, Verbrauch, Fahrbarkeit etc. zu untersuchen. Diese Simulationsumgebung setzt sich aus dem Streckenaufzeichnungssystem SASIMA, dem Verkehrssimulationsprogramm VERSIMA und dem Fahrsimulationsprogramm FASIMA zusammen.
In dieser Arbeit wird der Einfluss einer Reihe typischer Versuchsparameter auf die Schädigung der Verzahnungen und ihre Möglichkeit der zeitlichen Raffung bei der Erprobung eines automatisierten Handschaltgetriebes untersucht. Für die einzelnen Gänge werden in Abhängigkeit der untersuchten Parameter die Lastkollektive ermittelt, mit denen Schadensakkumulationsrechnungen durchgeführt und auf eine Referenzschädigung bezogen werden. Als Resultat liegen die relativen Schädigungen der einzelnen Gänge in Abhängigkeit der untersuchten Parameter vor. Anhand des vorliegenden Schädigungsmechanismus wird bestimmt, ob die Raffung zulässig ist oder nicht. Das Ergebnis ist eine Matrix, die das Raffungspotential der Parameter auf die Gänge und das gesamte Getriebe widerspiegelt. Um gemessene oder synthetisch erzeugte Geschwindigkeits- und Streckenprofile beurteilen zu können, wurden Kenngrößen zur Bewertung der Geschwindigkeits-, der Höhen- und der Kurvenprofile hergeleitet. Anhand dieser Kenngrößen kann das Einflusspotential dieser Profile auf die Schädigung des Getriebes ermittelt werden.
Untersucht wurden als fahrzeugspezifische Parameter das Fahrzeuggewicht, das Motormoment, die Hinterachsübersetzung und die Art des Schaltprogramms, ob manuelle oder automatische Gangwahl. Als streckenspezifische Parameter wurde das Höhenprofil und die Kurvigkeit, als fahrerspezifischer Parameter die Wunschgeschwindigkeit gewählt.
Als Untersuchungsergebnis liegt eine Matrix vor, die den qualitativen und quantitativen Einfluss der Parameter auf die Schädigung der Verzahnungen der einzelnen Gänge enthält. Daraus lässt sich ableiten, dass zur zeitraffenden Erprobung von Getrieben gangspezifische Versuche gefahren werden müssen.The shortening of launch cycles and increased cost pressure along with a simultaneous rise in quality is standing in the way of the development of new generations of cars. One proposal for resolving this conflict is to shorten complex and time consuming vehicle testing. The aim is to perform briefer tests by varying different parameters. The difficulty lies in determining the parameters in such a way that any damage caused in testing tallies with what is incurred under real conditions. Using simulation tools to do so offers the possibility to match the selection of parameters to be varied to the vehicle to be tested and thus to determine the potential for time saving ahead of testing.
The simulation environment developed at Stuttgart University's Institute of Machine Components (IMA) offers the possibility to test power trains set up at random on measured or synthetic road test-routes for strain, consumption, drivability, etc. This simulation environment consists of the test-route recording system SASIMA, the traffic simulation program VERSIMA and the driving simulation program FASIMA.
This work examines the effect of a series of typical test parameters on damage to gearing and its time saving potential when testing an automated manual gear change. On the basis of tested parameters for each individual gear the overall load complexes are determined which are used to perform damage accumulation calculations and compare them to a damage benchmark. As a result we get the relative damage to the individual gears relative to the test parameters. On the basis of the damage mechanism at hand a determination is made of whether or not any shortening is permissible. The result is a matrix, which reflects the parameters' potential for time saving on the gears and the entire transmission. In order to be able to assess measured or artificially produced speed and test-route profiles, parameters have been derived for evaluating speed, height and cornering profiles. These parameters enable the potential effect of these profiles on any transmission damage to be determined.
Vehicle specific parameters under test were vehicle weight, engine torque, rear axle ratio and the type of shift, i.e. manual or automatic gear change. Altitude profile and the degree of bends were chosen as test-route specific parameters, whilst the choice of speed was selected as a driver specific parameter.
As a test result we get a matrix, which contains the qualitative and quantitative effect of the parameters on any damage to the individual gears' teeth. From this it can be inferred that in order to save time testing transmissions gear specific tests must be run
Search for new resonances decaying to a or boson and a Higgs boson in the , , and channels with collisions at TeV with the ATLAS detector
No full textSee paper for full list of authors, 18 pages (plus author list + cover pages: 36 pages total), 13 figures, 1 table. Submitted to PLB. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2015-18/International audienceA search is presented for new resonances decaying to a or boson and a Higgs boson in the , , and channels in collisions at TeV with the ATLAS detector at the Large Hadron Collider using a total integrated luminosity of 3.2 fb. The search is conducted by looking for a localized excess in the / invariant or transverse mass distribution. No significant excess is observed, and the results are interpreted in terms of constraints on a simplified model based on a phenomenological Lagrangian of heavy vector triplets
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COMPENSATION OF DETECTOR SOLENOID IN SUPER-B
No full textThe SUPER-B detector solenoid has a strong 1.5 T field in the Interaction Region (IR) area, and its tails extend over the range of several meters. The main effect of the solenoid field is coupling of the horizontal and vertical betatron motion which must be corrected in order to preserve the small design beam size at the Interaction Point. The additional effects are orbit and dispersion caused by the angle between the solenoid and beam trajectories. The proposed correction system provides local compensation of the solenoid effects independently for each side of the IR. It includes 'bucking' solenoids to remove the solenoid field tails and a set of skew quadrupoles, dipole correctors and anti-solenoids to cancel linear perturbations to the optics. Details of the correction system are presented
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