Στην παρούσα εργασία πραγματοποιήθηκε παραμετρική μελέτη μεταλλικών καμπτικών επίπεδων πλαισίων με υποστυλώματα τύπου τετραγωνικής κοιλοδοκού (Square Hollow Section, SHS) και δοκών τύπου διπλού ταυ (IPE). Ζητούμενο αποτελούσε η ανάπτυξη εξισώσεων που θα συνδέουν χαρακτηριστικά της ανελαστικής απόκρισης των κατασκευών με την δυνατότητα αντισεισμικού σχεδιασμού σύμφωνα με την μέθοδο των δυνάμεων έχοντας όμως σαν αρχικό στόχο ένα επιθυμητό επίπεδο επιτελεστικότητας σύμφωνα με τον αντισεισμικό σχεδιασμό που βασίζεται στην νεότερη μέθοδο των μετακινήσεων και εκτιμούν πιο σωστά την επιρροή των φαινομένων Ρ-Δ στην ανελαστική απόκριση των δισδιάτατων καμπτικών πλαισίων. Αναδεικνύεται η επιρροή του ελέγχου ευστάθειας στον σχεδιασμό μεταλλικών καμπτικών πλαισίων. Χρησιμοποιούνται διάφορες παράμετροι που εκτιμήθηκε πως επηρεάζουν την ελαστική και ανελαστική απόκριση των κατασκευών όπως το όριο διαρροής του χάλυβα fy των μελών, ο αριθμός των ορόφων ns, που επηρεάζει άμεσα την ιδιοπερίοδο του συστήματος, η μορφή της ελαστικής απόκρισης των κατασκευών, οι οποίες διακρίνονται σε καμπτικού και διατμητικού τύπου (shear type, flexural type) σύμφωνα με τον συντελεστή ρ όπως ορίζεται από τον Chopra (2007a), καθώς επίσης και την παράμετρο πλαστικών ροπών a που σχετίζεται με το είδος του αναπτυσσόμενου ανελαστικού μηχανισμού. Ο υστερητικός νόμος που χρησιμοποιήθηκε και περιγράφει την ανελαστική απόκριση των μελών υπό ανακυκλιζόμενη δράση ταυτίζεται με το διγραμμικό υστερητικό νόμο με κράτυνση 3%, με απομείωση της αντοχής των μελών που συνδέεται άμεσα με την τοπική πλαστιμότητα των μελών σε κάθε ανελαστικό κύκλο φόρτισης. Παραμετρικές αναλύσεις έγιναν επίσης με τη χρήση διγραμμικού νόμου υστέρησης με κράτυνση 3% χωρίς την απομείωση της αντοχής των μελών κατά την ανελαστική τους απόκριση, με στόχο την διερεύνηση της επιρροής στην αντοχή των μελών κατά την ανελαστική τους απόκριση. Για την πραγματοποίηση της παρούσας μελέτης 57 καταγραφές παρελθοντικών σεισμών μακριά από το σεισμικό ρήγμα, αποτέλεσαν την διέγερση για την εκτέλεση των δυναμικών μη-γραμμικών αναλύσεων ώστε να ληφθεί υπόψη η επιρροή του συχνοτικού περιεχομένου των επιταχυνσιογραφημάτων στην απόκριση των συστημάτων. Τέλος, παρουσιάζεται παράδειγμα που συγκρίνει την προτεινόμενη μέθοδο με την μέθοδο των δυνάμεων αποδεικνύοντας την αποτελεσματικότητά της. / In this project, a parametric design of steel moment resisting frames with square hollow section type columns (Square Hollow Section, SHS) and double tee type of section (IPE) beams was made. It was desired to develop an equation connecting the inelastic response characteristics of structures designed according to the force-based method but having as initial target a desired performance level in accordance with seismic design based on the direct displacement-design method. Furthermore, it was desired to estimate the influence of P-Δ phenomena to the inelastic response of 2D moment resisting steel frames in a more correct way. The influence of stability control in the design moment resisting steel frames is highlighted. Various parameters that affect the elastic and inelastic response of structures are used, such as the yield strength of steel members fy, the number of storeys ns, which directly affects the eigenperiod of the system, the type of the elastic response of the structures, which are divided into flexural and shear type according to the coefficient ρ as defined by Chopra (2007a), and also the parameter of plastic moments α associated with the type of the developing plastic mechanism. The hysteretic law used, which describes the inelastic response of members under cyclic action, is the bilinear hysteretic law with hardening 3% and deterioration of members’ strength directly associated with the local ductility of members in each inelastic loading cycle. In addition, extra parametric analyses were made by using bilinear hysteretic law with 3% hardening without deterioration of strength of members in their inelastic response, in order to investigate the influence of strength deterioration on the resistance for members in the inelastic range. To carry out this study, 57 records of past earthquakes far from the seismic fault were used to perform the dynamic non - linear analyses, in order to take into account the influence of the frequency content of the accelerograms on the response of the systems. Finally, examples are presented comparing the proposed method with the method of forces demonstrating the effectiveness of the proposed method.

No description available.

L'étude expérimentale des propriétés radiatives de plasmas d'hélium hors équilibres peut être réalisée par spectroscopie d'émission, un diagnostic non intrusif qui ne perturbe pas le système. Dans cette thèse, ce diagnostic a été utilisé sur des plasmas créés dans des tubes à décharges et dans une machine linéaire magnétisée MISTRAL. Les données expérimentales ont été confrontées aux résultats théoriques issus du code de physique atomique SOPHIA (modèle collisionnel-radiatif). Les tubes à décharge se caractérisent par des températures électroniques de l'ordre de l'électron-Volt et des densités électroniques de l'ordre de 10 exposant 12 cm-3. La première partie des résultats de cette thèse a permis de montrer que, dans ces conditions, le modèle C.C.C. (Convergent Close Coupling) reproduit au mieux la dynamique atomique d'un tel système. Dans la machine MISTRAL, la deuxième partie des résultats de cette thèse met en évidence la signature spectroscopique (rapports d'intensités de raies et étutés de raies et études radiales), de la présence d'électrons énergétiques ionisants et de la diffusion des particules chargées à travers un champ magnétique. / The experimental study of the radiative properties of plasmas of helium out of equilibrium can be achieved by emission spectroscopy, a non-invasive diagnostic which does not affect the system. In this thesis, this diagnostic was used on plasmas created in discharge tubes and in the linear magnetized machine MISTRAL. The experimental data were compared with theoretical results coming from the atomic physics code SOPHIA (collisional-radiative model). The discharge tubes are characterized by electron temperatures of the order of the electron volt and electron densities in the range of 10 12 cm-3. The first part of the results of this thesis has shown that under these conditions, the CCC model (Convergent Close Coupling) reproduces in the best way the atomic dynamics of such a system. The second part of the results reveals the spectroscopic signatures (line intensities ratios and radial studies), in the machine MISTRAL, the presence of ionizing energetic electrons and the diffusion of charged particles through a magnetic field.

Le Modèle Standard de la physique des particules est une théorie quantique des champs qui décrit les particules élémentaires de la matière et leurs interactions. Le Large Hadron Collider (LHC) au CERN à Genève a été construit afin de tester les prédictions théoriques du Modèle Standard, en produisant des collisions proton-proton avec des énergies au centre de masse jamais atteintes auparavant. ATLAS est l'un des quatre détecteurs construits sur le LHC. Il est optimisé pour reconstruire les particules et leur produits de désintégrations issus de ces collisions. La partie technique de cette thèse est liée au détecteur à pixels d'ATLAS qui fournit une mesure précise des paramètres des traces à côté du point d'interaction. Ceci est important pour l'identification des jets issus de quarks beaux. Nous présentons une analyse des propriétés des amas de pixels avec les données de muons cosmiques collectées en 2008. Ce travail porte essentiellement sur l'étude de l'effet du seuil des pixels sur la taille, la charge et la position des amas principaux associés aux traces à grand angle d'incidence, avec les données et les simulations. Nous avons réalisé aussi une des premières mesures de la section efficace de production de jets issus de quarks beaux au LHC avec les données de collisions proton-proton à une énergie de 7 TeV au centre de masse. C'est la deuxième analyse présentée dans ce document. Une section efficace différentielle de production de jets b a été mesurée avec les données enregistrées par ATLAS en 2010, utilisant les muons dans les jets semi-leptoniques afin d'extraire la fraction de jets b. Les résultats de la mesure sont en bon accord avec les prédictions de la QCD du Modèle Standard. / The Standard Model of elementary particle physics is a quantum field theory describing the fundamental particles which constitute matter and the interactions between them. The Large Hadron Collider (LHC) at CERN in Geneva was built with the intention of testing various Standard Model predictions, by providing proton-proton collisions at a centre-of-mass energies never recorded before. The ATLAS detector is one of the four particle experiments constructed at the LHC. It is designed to reconstruct particles and their decay products originating from these collisions. The technical part of this thesis is related to the ATLAS pixel detector which provides a precise measurement of tracks next to the interaction point. This is important for the identification of particle jets which originate from bottom quarks. We present an analysis of the pixel cluster properties using cosmic rays data collected in 2008. The main part of this work is dedicated to the study of the effect of online pixel threshold that impacts especially the charge, the size and the position of main clusters associated to tracks at high incidence angle, with data and Monte Carlo. We performed also one of the first measurements of the b-jet production cross section in proton-proton collisions at sqrt{s} = 7 TeV with the ATLAS detector. It is the second analysis presented in this document. A differential b-jet production cross section was measured with the 2010 dataset recorded by the ATLAS detector, using muons in jets to estimate the fraction of b-jets. The measurement is in good agreement with the Standard Model QCD predictions.

Magister Legum - LLM

Dans les collisions Pb-Pb au LHC, un milieu chaud et dense formé de quarks et de gluons déconfinés est formé, communément appelé Plasma de Quarks et de Gluons (PQG). Le PQG est l’état hypothétique de l’univers primordial quelques microsecondes après le Big Bang et constituerait encore à ce jour le cœur des étoiles à neutrons. Une des signatures les plus frappantes de l’occurrence du PQG lors de collisions d’ions lourds est la suppression des jets. Ce phénomène appelé étouffement des jets est attribué au mécanisme de perte d’énergie du parton à l’origine du jet lors de son trajet au travers du milieu formé par le PQG.Les deux dernières décennies ont vu l’émergence d’une formulation théorique du phénomène d’étouffement des jets dans le cadre de la Chromo Dynamique Quantique. La perte d’énergie étant le plus fréquemment attribuée dans la littérature à des processus radiatifs et collisionnels. Un nouveau mécanisme de perte d’énergie à été étudié dans ce travail de thèse qui outre la description des effets de diffusions multiples, met en œuvre une perte d’énergie radiative induite par un champ chromomagnétique, de sorte qu’un parton rapide se propageant au travers du milieu ressentira l’effet des champs magnétique et de couleur tout en subissant des diffusions multiples avec les particules du milieu.De plus, les modèles théoriques prédisent une dépendance de la perte d’énergie avec la charge de couleur et la masse du parton issu d’une diffusion à grand transfert d’impulsion lors de sa traversée du milieu.Une telle dépendance en masse peut être étudiée en mesurant la production de hadrons et de jets contenant des quarks lourds dans les collisions pp, p-Pb et Pb-Pb au LHC. Dans cette thèse, un modèle original du milieu est présenté, décrit comme un ensemble de centres de diffusion statiques colorés en présence d’un champ chromomagnétique, de même qu’une description du mécanisme de perte d’énergie associé. Enfin, la mesure de la production de jets issus de quarks beaux avec le détecteur ALICE dans les colllsions pp et p-Pb à l’énergie de 5.02 TeV au LHC à l’aide d’une méthode d’étiquetage utilisant le paramètre d’impact des traces est présenté dans cette thèse. / In Pb-Pb collisions at the LHC, a hot and dense medium of deconfined quarks and gluons is formed, the so-called Quark-Gluon Plasma (QGP).The QGP is conjectured to be the state of matter of the early Universe up to few microseconds after the Big Bang and may still exist in the core of neutron stars. One of the most striking signatures of the QGP formation in heavy-ion collisions is the suppression of jet production. This phenomenon, called jet quenching, is ascribed to the energy lost by the initial parton while traveling through the QGP medium.In the last two decades, many theoretical developments of the theory of jet quenching have been formulated within pQCD.The main energy loss mechanisms proposed in the literature are attributed to radiative and collisional processes. Another kind of energy loss is developed in this work comprises a background field induced radiative energy loss which besides that besides scattering effects. Under the suggested model, a fast parton propagating through the medium will feel the effect of the color magnetic and the color electric fields while undergoing multiple scatterings with the particles in the medium.Besides, theoretical models predict that energy loss depends on the color charge and mass of the hard-scattered parton traversing the medium. Such mass dependence can be studied by measuring the production of hadrons and jets containing heavy-quarks in pp, p-Pb and Pb-Pb collisions at the LHC.In this thesis report, a new model for the medium is presented, which is described as a collection of static colored scattering centers in the presence of a chromomagnetic field, together with the description of the related energy loss mechanism. The ALICE measurement of b-jet production in pp and p-Pb collisions at $sqrt{s_{mathrm{NN}}}=5.02$ TeV using an impact parameter based tagger is also presented.

Introdução: A cesárea vem aumentando progressivamente no Brasil e no mundo. Dentre os fatores associados a esse evento, destaca-se a cesárea prévia. Embora a maioria dos partos realizados em mulheres com história de cesárea seja cirúrgico, autores tem demonstrado altos índices de partos vaginais após cesárea - PVAC com baixa incidência de complicações. Diante do alarmante crescimento das taxas de cesárea, o presente estudo objetiva identificar a proporção e o perfil das mães com história de repetição de cesárea - RC no Estado de São Paulo, em 2012. Métodos: Os dados provenientes do Sistema de Informações Sobre Nascidos Vivos foram vinculados aos do Cadastro Nacional de Estabelecimentos de Saúde. Os resultados a respeito das características das mães com história de RC foram analisados segundo características da gestação, do recém-nascido RN e segundo tipo do hospital do parto. Os dados foram descritos na forma de medidas de proporção (frequências), com diferenças entre variáveis de interesse verificadas pelos testes de proporção e de médias (nível de significância de 5 por cento ). Resultados: Foram estudados 273.329 nascidos vivos de mães com pelo menos um filho anterior. Destes, 43 por cento nasceram por RC e 7,4 por cento por PVAC. As mães que realizaram CR são mais velhas e mais escolarizadas e os RNs nascidos desse grupo apresentaram menor proporção de baixo peso ao nascer. O início do pré-natal no primeiro trimestre e a realização de 7 ou mais consultas de pré-natal foi mais frequente no grupo CR. Termo precoce foi a classificação mais frequente para idade gestacional dos que nasceram por CR. Em contrapartida, os RNs por parto vaginal apresentaram maiores proporções de termo tardio do que aqueles por repetição de cesárea. A RC foi mais frequente nos hospitais sem vínculo com o Sistema Único de Saúde - SUS (44,1 por cento ). Dentre esses, a maioria (54,3 por cento ) teve idade gestacional classificada como termo precoce. Somente o grupo SUS alcança uma melhor proporção de termo pleno (46,5 por cento ), contudo esse grupo tem a frequência mais elevada de termos tardios (10,9 por cento ). Conclusão: As altas taxas de cesárea de repetição, principalmente no setor privado, evidenciam a necessidade de melhoras no modelo de atenção ao parto no Estado de São Paulo. / Background: Cesarean section has been progressively increasing in Brazil and worldwide. Among the factors associated with this event stands out a prior cesarean delivery. Although most deliveries in women with a prior cesarean delivery is surgical, authors have demonstrated high levels of vaginal births after cesarean - VBAC with low incidence of complications. Given the alarming increase in cesarean rates, this study aims to identify the proportion and profile of mothers with repeat cesarean delivery - RCD in the State of São Paulo, in 2012. Methods: Data from Live Births Information Systems were linked to the National Health Establishments Registration. The results about the characteristics of mothers with RCD were analyzed according to characteristics of pregnancy, newborn and type of maternity hospital. Data were presented in the form of proportion measures (frequencies), with differences between variables of interest verified by the proportion and average tests (5 per cent significance level). Results: 273 329 live births of mothers with at least one previous child were studied. 43 per cent of these were born by RCD and 7.4 per cent by PVAC. Mothers who underwent RCD are older and more highly educated and newborn infants in this group had a lower incidence of low birth weight. The beginning of prenatal care in the first trimester and the realization of 7 or more prenatal visits was more frequent in the RCD group. Early term was the most frequent rating for gestational age born by RCD. In contrast, newborns by vaginal delivery had greater proportions of late term than those by repeat cesarean. The RCD was more common in hospitals not affiliated with the Unified Health System - UHS (44.1 per cent ). In these, the majority (54.3 per cent ) of newborn had gestational age of early term. Only the UHS group achieves a better proportion of full term (46.5 per cent ), however, this group has the highest frequency of late terms (10.9 per cent ). Conclusion: The high repeat cesarean rates, especially in the private sector, highlight the need for improvements in childbirth care model in São Paulo.

Made available in DSpace on 2015-03-05T19:11:29Z (GMT). No. of bitstreams: 0 Previous issue date: 22 / Nenhuma / Na esteira da recente desproporção da remuneração executiva e dos escândalos corporativos, alguns críticos têm reclamado que essa é excessiva. Outros têm reclamado que a remuneração não é propriamente atrelada ao desempenho. Adicionalmente, a tênue conexão entre a remuneração e o desempenho, tem levantado considerações a respeito dos propósitos dos executivos e a ineficácia dos mecanismos de governança corporativa, especialmente nos Estados Unidos e no Reino Unido. Consequentemente, a determinação da remuneração dos gestores tem emergido como uma questão de considerável importância na literatura de governança corporativa e numerosos estudos têm buscado identificar os mais importantes fatores que impactam na remuneração executiva. O objetivo dessa pesquisa é estudar os determinantes da remuneração executiva na América Latina com base em indicadores contábeis, indicadores do mercado de ações e características de governança corporativa (incluindo características do conselho e do principal executivo, e estrutura / In the wake of the recent runaway executive compensation and corporate scandals, some critics have claimed that the compensation of executives is excessive. Others have claimed that the compensation is not properly tied to performance. Furthermore, the tenuous link between incentive ompensation and performance has raised concerns regarding executive entrenchment and ineffectiveness of corporate governance mechanism, especially in the United States and the United Kingdom. Consequently, the determination of management compensation has emerged as an issue of considerable academic importance in the corporate governance literature, and numerous studies have tried to identify the most important factor impacting executive compensation. The aim of this research is to study the determinants of executive compensation in Latin America from financial accounting measures, stock market measures, and corporate governance characteristics (including both board and CEO characteristics, and owner

La désexcitation des fragments de fission reste mal comprise et les modèles théoriques ne permettent pas de prédire et d’expliquer toutes les corrélations observées dans le processus de fission. Il y a un besoin important de données simultanées sur les émissions de neutrons et de rayonnements gamma et sur l’énergie cinétique des fragments de fission. Dans ce contexte, l’utilisation d’un détecteur de fragments de fission avec le détecteur CARMEN permettrait de fournir des données contraignantes pour les modèles grâce à la mesure simultanée de la multiplicité neutronique, de l’énergie totale gamma rayonnée, de l’énergie cinétique totale des fragments et potentiellement de l’énergie totale neutron. L’objectif de ce travail de thèse a consisté à développer un détecteur de fragments de fission et à l’utiliser en association avec CARMEN pour réaliser des mesures calorimétriques de la fission. Dans un premier temps, nous avons développé un nouveau détecteur pour l’étude de la fission dont le principe est de mettre un actinide en solution dans un scintillateur organique. Des simulations Monte Carlo et différentes expériences sous faisceau de neutrons ont permis de caractériser et d’optimiser les performances de ce détecteur qui peut être utilisé comme trigger fission pour différentes mesures de sections efficaces de fission, de taux de fission spontanée ou encore comme veto fission. Dans un second temps, nous avons étudié les possibilités de mesure de l’énergie totale gamma et neutron rayonnée dans la fission avec CARMEN grâce à la caractérisation expérimentale de ses performances et à la simulation Monte Carlo et l’analyse de sa réponse « prompte » aux neutrons et aux rayonnements gamma / Still, the nuclear fission process and the de-excitation of the fission fragments is not fully understood. Current theoretical models can not predict and explain correctly every experimentally observed correlations, and new correlated data upon neutron emission, gamma-ray emission and kinetic energy of the fission fragments are needed. In this context, coincident use of a fission fragment detector and the CARMEN detector would provide compelling data for these models by measuring both neutron multiplicity, total gamma-ray energy, total kinetic energy and possibly total neutron energy. The work presented here consists in developing a fission fragment detector and using it together with CARMEN in order to perform fission calorimetry measurements. Initially, we developed a new detector for fission studies whose principle is dissolving the actinide of choice into an organic liquid scintillator. Monte Carlo simulations and neutron induced experiments were used to fully characterize its performances and shown it can be used as a fission trigger for various measurements, such as fission cross section or spontaneous fission rate measurements, and used as a fission veto. The second part of this work was dedicated to the study of CARMEN’s ability to measure the total gamma-ray energy and total neutron energy released in fission. For this purpose, lab characterization of the detector’s performances and Monte Carlo simulation and analysis of its “prompt” response to neutrons and gamma-rays were performed

Vacuum polarization integral involves the vector spectral functions which can be experimentally determined. As the dominant uncertainty source to the integral, the precision measurement of the %born cross section of $e^+e^-\rightarrow\pi^+\pi^-(\gamma)$ as a function of energy from $2\pi$ threshold to 3GeV is performed by taking the ratio of $e^+e^-\rightarrow\pi^+\pi^-(\gamma)$ cross section to $e^+e^-\rightarrow\mu^+\mu^-(\gamma)$ cross section which are both measured with {\babar\ }data using ISR method in one analysis. Besides that taking the ratio of the cross sections of the two processes can cancel several systematic uncertainties, the acceptance differences between data and MC are measured using the same data, and the corresponding corrections are applied on the efficiencies predicted by MC which can control the uncertainties. The achieved final uncertainty of the born cross section of $e^+e^-\rightarrow\pi^+\pi^-(\gamma)$ in $\rho$ mass region ($0.6\sim0.9$GeV) is 0.54\%. As a consequence of the new vacuum polarization calculation using the new precision result of the $e^+e^-\rightarrow\pi^+\pi^-(\gamma)$ cross section, the impact on the SM prediction of muon anomalous magnetic moment $g-2$ is presented, which is also compared with other data based predictions and direct measurement.