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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Mesure des fonctions de fragmentation des jets et de leurs moments dans les collisions pp à Vs = 2.76 TeV avec ALICE au LHC / Measurement of jet fragmentation functions and of their moments in pp collisions at Vs = 2.76 TeV with ALICE at the LHC

Wang, Mengliang 10 December 2016 (has links)
Un cross-over entre la matière nucléaire ordinaire et le plasma de quarks et gluons (PQG) est prédit par la QCD sur réseau à bas PB et haute température. Expérimentalement les collisions d'ions lourds ultrarelativistes sont utilisées pour étudier cet état dense et chaud. Produits lors d'un processus dur en début de collision, un parton de grande énergie en perd dans le milieu avant de fragmenter en une gerbe de hadrons appelée jet. Une étude de la modification de la structure et de la fragmentation du jet dans le milieu par rapport au vide permet d'améliorer notre connaissance du PQG. Les fonctions de fragmentation (FF) d'un jet décrivent les distributions en impulsion des hadrons dans ce dernier. Dans les collisions proton-proton (pp), leur mesure est importante pour comprendre les mécanismes de fragmentation de partons. Dans les collisions noyau-noyau, elle permet d'étudier les mécanismes de perte d'énergie. Cependant, la présence d'un important bruit de fond qui fluctue rend la mesure complexe. Il a alors été suggéré de mesurer les moments des FF qui y seraient moins sensibles. Le détecteur ALICE au LHC a des capacités de trajectométrie uniques permettant la mesure des particules chargées jusqu'à des impulsions de 150 MeV/c rendant possible une étude fine de la structure du jet et de ses FF. Les calorimètres électromagnétiques (EMCal et DCal) peuvent aussi être utilisés pour améliorer la mesure de l'énergie du jet. Nous présentons les mesures des FF des jets chargés et les premières études des moments des FF dans les collisions pp à .s=2.76 TeV dans ALICE. Une partie du travail est aussi dédiée à l'implémentation de la géométrie de DCal dans le logiciel d'analyse. / A cross-over between ordinary nuclear matter and a state of deconfined quarks and gluons, the Quark Gluon Plasma (QGP), is predicted by lattice QCD at low PB and high temperature. Experimentally, ultra-relativistic heavy ion collisions are used to produce and to study the hot and dense QGP medium. Produced in a hard scattering at the early stage of the collision a highly energetic parton is expected to lose energy in the medium before fragmenting into a spray of hadrons called jet. A study of the modification of the jet structure and of its fragmentation pattern in medium compared to the vacuum case should provide insights into the QGP properties. The jet fragmentation functions (FF) describe the momentum distribution of hadrons inside a jet. In proton-proton (pp) collisions their measurement is important for understanding the mechanisms of parton fragmentation while it can shed light on the energy loss mechanisms in nucleus-nucleus (AA) collisions. However, the presence of a large fluctuating background in AA makes the measurement a challenging task. The use of FF moments has been proposed to overcome this difficulty. The ALICE detector at the LHC has unique tracking capabilities enabling to measure charged particles down to transverse momenta of 150 MeV/c. This allows assessing possible modifications of the jet structure and FF. The electromagnetic calorimeters (EMCal and DCal) can also be used to improve the measurement of the jet energy. We present the measurements of charged-jet FF and the first studies of FF moments in pp collisions at .s=2.76 TeV in ALICE. Part of the work is also dedicated to the implementation of the DCal geometry in the ALICE offline software.
42

"As If She Had No Secrets:" Approach, Recognition, and Coming of Age In Alice Munro's Lives of Girls and Women

Sweeney, Catherine Laura January 1990 (has links)
No description available.
43

Study of the angular correlation between heavy-flavour decay electrons and charged unidentified particles in pp and p-Pb collisions with ALICE / Estudo da correlação angular entre elétrons oriundos de quarks pesados e partículas carregadas em colisões pp e p-Pb com o detector ALICE

Oliveira Filho, Elienos Pereira de 05 December 2014 (has links)
The aim of relativistic heavy-ion collisions is to investigate the properties of the Quark-Gluon Plasma (QGP) phase, that is achieved at high-enough temperatures and/or densities. In this context, light on heavy-ion collisions (e. g. p-Pb) are used to assess Cold Nuclear Matter effects (CNM), while elementary hadronic collisions (e. g. proton-proton) provide tests for QCD (Quantum Chromodynamics) based calculations and baseline for studies with heavy- ions. Heavy quarks, i. e. charm and beauty, are very convenient in the characterization of the QGP. They are produced via initial hard parton-parton scatterings at the early stages of the collision and, therefore, they are a self-generated probe for the system created in the reaction. In this work the angular correlation between electrons from heavy-flavour hadron decays and charged particles was studied in pp (2.76 and 7 TeV) and p-Pb (5.02 TeV) collisions at the CERN Large Hadron Collider, using the ALICE detector. The correlation strengths were evaluated as a function of multiplicity in p-Pb collisions. In pp collisions the relative beauty (and charm) contribution to the total heavy-flavour decay electron yield was estimated using the measured correlation distribution and Monte Carlo templates. / O próposito de colisões entre íons pesados relativísticos é investigar as propriedades do plasma de quarks e gluons (QGP, do inglês Quark-Gluon Plasma). A transição de fase, de um estado hadrônico para o QGP, ocorre em regimes onde a temperatura e/ou densidade atingem um valor suficientemente alto. Neste contexto, colisões entre íons pesados e leves (por exemplo, p-Pb) permitem acessar efeitos devido à matéria nuclear fria (CNM, do inglês Cold Nuclear Matter) e colisões elementares (por exemplo, próton-próton) são usadas como referência para estudos com íons pesados, além de proporcionarem testes para cálculos de QCD perturbativa. Quarks pesados, isto é charm e bottom, são ferramentes muito convenientes no estudo e caracterização do QGP. Essas partículas são produzidas através de espalhamento duro nos instantes iniciais da colisão e, portanto, elas atuam como uma sonda externa para o sistema criado na reação. Esse trabalho consiste no estudo da correlação angular entre elétrons oriundos de quarks pesados e partículas carregadas, em colisões pp (2.76 e 7 TeV) e p-Pb (5.02 TeV), no acelerador LHC (do inglês Large Hadron Collider) do CERN, usando o detector ALICE (do inglês A Large Ion Collider Experiment). A distribuição angular mencionada foi medida em função da multiplicidade do evento, no caso de colisões p-Pb. Em colisões pp, a contribuição relativa de quarks charm e bottom para o total de elétrons provenientes de quarks pesados foi estimada usando a função de correlação obtida.
44

Étude de la densité de particules chargées et des mésons vecteurs de basses masses en collisions Pb-Pb à sqrt(s)NN = 2.76 TeV dans ALICE au LHC / Study of the charged particle density and low mass vector mesons in Pb-Pb collisions at sqrt(s)NN =2.76 TeV in ALICE at LHC

Guilbaud, Maxime 25 October 2013 (has links)
La matière que nous connaissons est composée de hadrons dont les quarks et les gluons sont les composants élémentaires. Ces derniers n'existent pas libres dans la matière ordinaire et sont donc en permanence confinés dans les hadrons. Cependant, d'après les prédictions théoriques, quelques microsecondes après le Big Bang, la température était suffisamment élevée pour que les quarks et les gluons ne soient pas contenus dans les hadrons. Il s'agit d'une phase déconfinée de la matière hadronique appelée Plasma de Quarks et Gluons (QGP). Le Large Hadron Collider (LHC) au CERN (Genève) est un accélérateur de particules permettant d'accélérer, entre autres, des ions et de produire des collisions à des énergies dans le centre de masse par nucléons allant jusqu'à plusieurs TeraélectronVolts. Il est ainsi possible d'atteindre des températures permettant de recréer cette phase de QGP pour en étudier les propriétés. C'est dans ce cadre que se place l'expérience ALICE (A Large Ion Collider Experiement) qui est dédiée à l'étude des collisions d'ions lourds ultra-relativistes. Le temps de vie du QGP étant trop faible, il n'est pas possible de l'étudier directement. Il est alors nécessaire d'utiliser des observables indirectes. Ce travail de thèse s'inscrit directement dans ce programme de physique par le biais de l'étude des collisions d'ions lourds à 2.76 TeV. Deux observables sont abordées : la densité de particules chargées par unité de pseudorapidité et les mésons vecteurs de basse masse (rho, omega et phi) dans le canal dimuons. La première observable permet d'accéder à des informations sur les conditions initiales et la dynamique sous-jacente des mécanismes de production de particules. La mesure est réalisée sur la gamme en pseudo-rapidité la plus large jamais atteinte au LHC (10 unités) grâce au développement d'une méthode d'analyse originale dite " méthode des vertex déplacés ". La technique employée et les résultats obtenus sont décrits dans le chapitre 3. L'étude des mésons vecteurs de basse masse permet d'accéder à la production d'étrangeté via le méson phi et à la symétrie chirale à travers la modification de la fonction spectrale du rho. L'analyse a été menée à l'aide du spectromètre à muons d'ALICE et les résultats obtenus sur le taux de production du méson phi par rapport au mésons rho et omega sont présentés dans le chapitre 4. Dans ce chapitre, une étude sur la sensibilité du détecteur aux effets liés à la restauration de la symétrie chirale est aussi menée / The matter is composed of hadrons of which quarks and gluons are the elementary components. These do not exist in a free state in ordinary matter and are therefore permanently confined in hadrons. However, according to theoretical predictions, a few microseconds after the Big Bang, the temperature was high enough to create a deconfined state of quarks and hadrons : the Quark and Gluon Plasma (QGP). The Large Hadron Collider (LHC) at CERN (Geneva) is a particle accelerator which accelerates, among others, ions and produces collisions with energies per nucleons in the center of mass up to several TeraelectronVolts. It is thus possible to achieve temperatures to recreate the QGP phase to study its properties. The experiment ALICE (A Large Ion Collider Experiment) is dedicated to the study of such ultra-relativistic heavy-ion collisions. The lifetime of the QGP being too low, it is not possible to study it directly. It is then necessary to use indirect observables. This PhD work is directly related to the study of heavy-ion collisions at 2.76 TeV. Two observables are discussed : the density of charged particles per unit of pseudorapidity and low mass vector mesons (rho, omega and phi) in the dimuon channel. The first observable gives access to informations about the initial conditions and the underlying dynamics of particle production mechanisms. The measurement is performed in the largest pseudorapidity range reached at the LHC (10 units) thanks to the development of an original analysis method called " displaced vertex technique ". The technique employed and the results obtained are described in Chapter 3. The study of low mass vector mesons allows to probe the production of strangeness via the phi meson and chiral symmetry through the ! spectral function modification. The analysis was conducted using the ALICE muon spectrometer and the results obtained from the production rate of the phi with respect to rho and omega are shown in Chapter 4. In this chapter, a study on the sensitivity of the detector to the effects related to the chiral symmetry restoration is also conducted
45

[en] EXILE EXPERIENCES IN ALICE BRILL S PHOTOGRAPHS. / [pt] A EXPERIÊNCIA DO EXÍLIO NAS FOTOGRAFIAS DE ALICE BRILL

NAYARA FERNANDES COELHO 27 February 2019 (has links)
[pt] Esta dissertação tem como propósito apresentar as fotografias de Alice Brill e sua relação com a trajetória pessoal da fotógrafa. O ponto de encontro entre as fotografias que ela produz e sua vida é o exílio, que transforma sua compreensão sobre o mundo a sua volta. Alice Brill nasceu na Alemanha em 1920 e residiu em Hamburgo até 1934, quando foi obrigada a deixar o país por causa de sua origem judaica. Neste período de exílio, ela percorreu um longo caminho até seu destino final, o Brasil. Está trajetória transformou o olhar de Brill e sua adaptação na cidade de São Paulo foi auxiliada pela sua arte. Dessa forma a artista expressou as dissonâncias que estava vivendo. Dentre sua vasta obra está a fotografia, que ela construiu ao longo da década de 50, apresentando um olhar distinto sobre as escolhas dos temas fotografados. Dentre os conjuntos que Brill construiu, as fotografias do hospital do juquery feitas em 1950 são importantes por diversos aspectos, pelo valor documental e artístico. / [en] The purpose of this dissertation is to present Alice Brill s photographs as well as their relationship with her personal life. The meeting point between her photographs and personal life is exile, which changes her understanding of the world. Alice Brill was born in Germany in 1920 and she has lived in Hamburg until 1934, when she was forced to leave her country due to her Jewish background. While in exile, she has traveled a long journey until her final destination, Brazil. These life experiences transformed Brill s gaze and her settlement in the city of São Paulo was facilitated by her art. In this way the artist expressed the dissonances she was experiencing. Among her vast work is photography, which she has built throughout the 1950s, presenting a distinct look to the subjects of her photography. Among the sets that Brill built, the photographs of the Juquery Hospital made in 1950 are important for several aspects, especially for their documentary and artistic value.
46

J/ψ production in proton-proton collisions at √s = 2.76 and 7 TeV in the ALICE Forward Muon Spectrometer at LHC / Production du J/ψ dans les collisions proton-proton à 2.76 et 7 TeV dans l’expérience ALICE auprès du LHC

Geuna, Claudio 12 November 2012 (has links)
Le plasma de quarks et de gluons (QGP) est un état de la matière nucléaire apparaissant à hautedensité d’énergie. En laboratoire, il est possible de reproduire de telles conditions grâce aux collisionsd’ions lourds aux énergies ultra-relativistes. ALICE (A Large Ion Collider Experiment) estl’expérience du LHC dédiée à la mise en évidence du QGP.Différentes signatures ont été proposées et étudiées expérimentalement comme manifestations duQGP. Parmi celles-ci, le méson J/ψ joue un rôle central. Il fait partie de la famille des quarkonia,états mésoniques (Q¯Q) formées d’un quark lourd c ou b et de son anti-quark, liés par un potentield’interaction forte. En 1986, Matsui et Satz proposèrent la suppression des charmonia (états liés cc)et notamment du J/ψ comme signature de la formation du plasma de quarks et de gluons.ALICE peut détecter le J/ψ à grande rapidité (2.5 < y < 4) via le canal de désintégration en deuxmuons. Cette thèse porte sur la mesure de la production du J/ψ, via le canal muonique, dans lescollisions pp à une énergie dans le centre de masse de 2.76 et 7 TeV. Elle a exploité les donnéesacquises en 2010 et 2011 auprès du collisionneur LHC.Tenter d’appréhender le mécanisme de production du J/ψ (et plus généralement du quarkonium)dans les collisions pp est un préalable nécessaire avant d’aborder le degré de complexité suivantque constitue le cas des collisions noyau-noyau. Il est également un test important pour la QuantumChromo Dynamics (QCD), la théorie de l’interaction forte, aux énergies très élevées du LHC. / Quarkonia are meson states whose constituents are a charm or bottom quark and its correspondingantiquark (Q¯Q). The study of the production of such bound states in high-energy hadron collisionsrepresents an important test for the Quantum Chromo-Dynamics. Despite the fact that the quarkoniumsaga has already a 40-year history, the quarkonium production mechanism is still an open issue.Therefore, measurements at the new CERN Large Hadron Collider (LHC) energy regimes are extremelyinteresting.In this thesis, the study of inclusive J/ψ production in proton-proton (pp) collisions at √s = 2.76and 7 TeV, obtained with the ALICE experiment, is presented. J/ψ mesons are measured at forwardrapidity (2.5 < y < 4), down to zero pT, via their decay into muon pairs (μ+μ−).Quarkonium resonances also play an important role in probing the properties of the stronglyinteracting hadronic matter created, at high energy densities, in heavy-ion collisions. Under suchextreme conditions, the created system, according to QCD, undergoes a phase transition from ordinaryhadronic matter to a new state of deconfined quarks and gluons, called Quark Gluon Plasma(QGP). The ALICE experiment at CERN LHC has been specifically designed to study this state ofmatter. Quarkonia, among other probes, represents one of the most promising tools to prove the QGPformation. In order to correctly interpret the measurements of quarkonium production in heavy-ioncollisions, a solid baseline is provided by the analogous results obtained in pp collisions.Hence, the work discussed in this thesis, concerning the inclusive J/ψ production in pp collisions,also provides the necessary reference for the corresponding measurements performed in Pb-Pb collisionswhich were collected, by the ALICE experiment, at the very same center-of-mass energy pernucleon pair (√sNN = 2.76 TeV).
47

Les empreintes des corps dans l'oeuvre d'Alice Munro / The imprints of bodies in Alice Munro’s stories

Bentley, Lucile 26 October 2018 (has links)
Cette thèse met en relation la représentation des corps dans l’œuvre d’Alice Munro avec le processus de l’empreinte tel qu’il a été mis au jour par Georges Didi-Huberman. La description des corps des personnages partage la même essence dialectique que l’empreinte : elle saisit une matière tout en laissant entrevoir le mouvement qui a donné naissance à la forme, elle est la conséquence d’un contact mais n’advient que dans la distance et son unicité fait signe vers le multiple. Le corps et son rapport au monde qui l’entoure met aussi en lumière une relation de ressemblance et de contact, une relation mutuelle que les mots eux-mêmes font transparaître dans une expression qui tend vers le lyrisme. Enfin, les corps représentés dans la fiction munrovienne ne sont pas de simples copies du réel mais sont véritablement créateurs en devenant les matériaux interpersonnels de la création artistique. Cette étude de la représentation des corps dans l’œuvre d’Alice Munro tente de montrer les enjeux de l’attention au corps, en particulier ceux du care, et comment cette attention influence l’écriture fictionnelle. / This dissertation examines the relationship between the representation of bodies in Alice Munro’s work and the imprint process as characterized by Georges Didi-Huberman. The description of the characters’ bodies gives evidence of the same dialectical essence as imprints: it attempts to fix the body matter while making movement visible, it is the product of a contact but becomes apparent only from a distance and its unicity foreshadows its multiplicity. The body and its link to the world around also displays a relationship of resemblance and contact based on reciprocity. It is conveyed through words and an expression that tends to lyricism. Finally, bodies represented in Munro’s fiction are not mere copies of the real but are creative and interpersonal as they become the very material of artistic creation. This study of the representation of bodies in Alice Munro’s work attempts to show what being attentive to bodies entails, in particular in the context of care studies, and how this attention to bodies influences fictional writing.
48

Det som syns men inte alltid finns : En diskursteoretisk analys av det svenska barnskyddet inom socialtjänsten / What can be seen but not always found : A Discourse Theoretical Analysis of the Swedish Social Service Child Protection

Wåhlström, Anna Emelie January 2012 (has links)
No description available.
49

Study of the angular correlation between heavy-flavour decay electrons and charged unidentified particles in pp and p-Pb collisions with ALICE / Estudo da correlação angular entre elétrons oriundos de quarks pesados e partículas carregadas em colisões pp e p-Pb com o detector ALICE

Elienos Pereira de Oliveira Filho 05 December 2014 (has links)
The aim of relativistic heavy-ion collisions is to investigate the properties of the Quark-Gluon Plasma (QGP) phase, that is achieved at high-enough temperatures and/or densities. In this context, light on heavy-ion collisions (e. g. p-Pb) are used to assess Cold Nuclear Matter effects (CNM), while elementary hadronic collisions (e. g. proton-proton) provide tests for QCD (Quantum Chromodynamics) based calculations and baseline for studies with heavy- ions. Heavy quarks, i. e. charm and beauty, are very convenient in the characterization of the QGP. They are produced via initial hard parton-parton scatterings at the early stages of the collision and, therefore, they are a self-generated probe for the system created in the reaction. In this work the angular correlation between electrons from heavy-flavour hadron decays and charged particles was studied in pp (2.76 and 7 TeV) and p-Pb (5.02 TeV) collisions at the CERN Large Hadron Collider, using the ALICE detector. The correlation strengths were evaluated as a function of multiplicity in p-Pb collisions. In pp collisions the relative beauty (and charm) contribution to the total heavy-flavour decay electron yield was estimated using the measured correlation distribution and Monte Carlo templates. / O próposito de colisões entre íons pesados relativísticos é investigar as propriedades do plasma de quarks e gluons (QGP, do inglês Quark-Gluon Plasma). A transição de fase, de um estado hadrônico para o QGP, ocorre em regimes onde a temperatura e/ou densidade atingem um valor suficientemente alto. Neste contexto, colisões entre íons pesados e leves (por exemplo, p-Pb) permitem acessar efeitos devido à matéria nuclear fria (CNM, do inglês Cold Nuclear Matter) e colisões elementares (por exemplo, próton-próton) são usadas como referência para estudos com íons pesados, além de proporcionarem testes para cálculos de QCD perturbativa. Quarks pesados, isto é charm e bottom, são ferramentes muito convenientes no estudo e caracterização do QGP. Essas partículas são produzidas através de espalhamento duro nos instantes iniciais da colisão e, portanto, elas atuam como uma sonda externa para o sistema criado na reação. Esse trabalho consiste no estudo da correlação angular entre elétrons oriundos de quarks pesados e partículas carregadas, em colisões pp (2.76 e 7 TeV) e p-Pb (5.02 TeV), no acelerador LHC (do inglês Large Hadron Collider) do CERN, usando o detector ALICE (do inglês A Large Ion Collider Experiment). A distribuição angular mencionada foi medida em função da multiplicidade do evento, no caso de colisões p-Pb. Em colisões pp, a contribuição relativa de quarks charm e bottom para o total de elétrons provenientes de quarks pesados foi estimada usando a função de correlação obtida.
50

The geochemistry of sediments and mine tailings in the Alice Arm area

Losher, Albert Justin January 1985 (has links)
A geochemical study of the composition of natural sediments and contaminating mine tailings in Hastings and Alice Arms has been carried out. Apart from the geochemical investigation on the solid fraction, pore waters from six sediment cores have been analyzed to evaluate the diagenetic processes in the sediments of these two inlets. Differences in the mineralogy as well as in the chemical composition of the sediments were used to distinguish the natural sediments from contaminated sediments and pure tailings. In Alice Arm, two types of tailings could be differentiated with these methods. The first tailings type originated from the Kitsault Mo-deposit, which was mined in the past two decades by the B.C. Molybdenum Corporation and AMAX/Canada. These tailings are characterized by a number of features which make them distinguishable from natural sediments. The K-feldspar content of the tailings is significantly increased, mainly at the expense of plagioclase, which is the main characteristic for the mineralogical identification of this tailings type. The enhanced K-feldspar content is the cause for increased K and Rb values in the Mo-mine tailings. Another indicator specific to these recent tailings is an increased Mo content. The second tailings type is derived from an older mining operation in the Kitsault Valley, most likely the Dolly Varden Silver Mine. A specific indicator for these tailings is their high Ba content which is due to large amounts of barite. This mineral phase could be identified by X-ray diffraction methods in a heavy mineral fraction of the relevant sediment layers. Both tailings types show enrichment in their Pb, Zn and S concentrations, caused by an increased amount of metal-sulphides in the ore materials. In this area, these elements can therefore serve as a general indicator for the contamination of natural sediment with either tailings type. The interstitial water analyses indicated that the sediments in both inlets become reducing at a fairly shallow depth (10-15 cm), resulting in the mobilization of Mn, Fe and Mo from the solid phase. In the deeper parts of the cores, consumption of these metals could usually be observed which is likely due to precipitation of authigenic components. The dissolved Mo concentrations in the sediments contaminated with the modern tailings were much higher than in the natural sediments. In the pore water of the pure tailings the concentration reaches some 300 times that of the overlying water, which is the highest value ever reported for saline pore waters. These high Mo concentrations must support a flux of Mo from the sediment into the overlying water, and it is shown that such a flux could increase the inventory of naturally occurring dissolved Mo in the deep waters of Alice Arm by up to 4%. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

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