Concrete-Filled Steel Tubular (CFST) columns are increasingly being used because of their many advantages, including high strength, high ductility, and higher fire resistance than conventional steel or concrete columns of the same size. In order to maximise the advantages of CFST column, composite action of the column should be ensured. In realistic structures, the load is not directly applied to the entire CFST column section and is introduced from the beam-column connection. Simple shear connections, which are usually preferred in constructions, are only connected to the external face of the steel tube and there is an issue about how this load is introduced to the concrete core, through the bond at the steel/concrete interface. There are fundamental errors in the load introduction mechanism assumed in various current design methods. Furthermore, based on this erroneous load introduction mechanism, construction methods, such as placing shear connectors inside the steel tube or using through-column plates, are recommended to ensure complete load introduction. However, these methods are either impractical or uneconomical. The aim of this project, therefore, is to develop a thorough understanding of the load introduction mechanism and to use the new insights to assess design implications, for both ambient temperature and fire safety design. The research has been conducted through physical testing, extensive numerical modelling and detailed analytical derivations. A series of new load introduction tests, in which square CFST columns are loaded through simple fin plate connections, are carried out. These tests are designed to investigate the effects of changing column lengths below and above the connection, the effectiveness of using shear connectors inside the steel tube below the connection (according to Eurocode 4) and using a cap plate on the column top for load introduction into the concrete core. The test results indicate that the connection load is introduced to the concrete core through the column length above and within the connection or the cap plate on top of the column. This is different from the currently assumed mechanism of load introduction which assumes that load introduction occurs from underneath the connection. Below the connection, there is transfer of forces from the steel tube to the concrete core, but the total force in the column remains unchanged. Consequently, using shear connectors below the connection is ineffective in increasing CFST column strength, as has been demonstrated by the tests. The physical tests are supplemented by an extensive numerical parametric study to check whether the conclusions are applicable to different design conditions and to provide data for development of a new design method. The parameters include: section geometry (square, circular, and rectangular), position of load application to CFST column, dimensions of the square column cross-section, steel tube thickness, connection length, column length above the connection, column length below the connection, and maximum bond stress at the steel-concrete interface. The numerical simulation results confirm the experimental observations. Furthermore, the numerical simulation results indicate that the entire column length and the entire perimeter of the steel-concrete interface above and within the connection are engaged in load introduction. Based on the experimental and numerical simulation results, a simple calculation method has been proposed to calculate the column cross-section resistance under compression. According to this equation, the concrete compression resistance to the composite column is the minimum of the plastic resistance or the bond strength within and above the connection. This gives rise to a “concrete strength reduction factor” to account for incomplete load introduction, being the ratio of the load introduced to the concrete core through the interface bond to the concrete plastic resistance. Based on the new load introduction calculation method and using representative values of column dimensions and concrete cylinder strength, it has been demonstrated that complete load introduction can be achieved in almost all practical arrangements of concrete-filled tubular construction. For slender CFST column design, this concrete strength reduction factor should also be used to calculate the CFST column cross-section flexural stiffness. For a CFST column under combined axial compression and bending, the concrete strength reduction factor should be used when calculating the compression force, but should be ignored when calculating the bending resistance because composite action is not necessary for bending of the CFST column. The new load introduction mechanism induces additional compression in the concrete core and possible tension in the steel tube above the connection. Therefore, the concrete core of the column above the connection in multi-storey construction should be designed to resist the additional compression force. For the steel tube, in ambient temperature design, the steel contribution ratio (steel section resistance/plastic resistance of composite cross-section) of the top floor column should be at least 0.25. For fire resistance design, the steel contribution ratio of the top floor columns, those on the floor below the top floor, and those two floors below the top floor, should not be less than 0.5, 0.33, and 0.25 respectively.

The main goal of this thesis is a comparison of tools used for web page accessibility evaluation, mainly their ability to find an accessibility issues defined in US law Section 508 paragraph § 1194.22 Web-based intranet and internet information and applications. A new web page created for the tool analysis, which contains accessibility issues described in paragraph § 1194.22, has been used to evaluate how many issues the tool can find. Based on the analysis results every tool is scored and the final ranks are decided. The results of the analysis and the final ranks are the main outcome of this thesis. The theoretical part of the thesis describes accessibility in detail and introduces the main dissabilities affecting their ability to use computers. A detailed description of all Section 508 rules is present as well. It consists of translation of every rule into czech language, short description of the rule's meaning and points when the rule is met. The practical part describes the test web page, analysis proces and results in detail.

Orientador: Antonieta Keiko Kakuda Shimo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Enfermagem / Made available in DSpace on 2018-08-24T10:50:57Z (GMT). No. of bitstreams: 1 Mafetoni_ReginaldoRoque_M.pdf: 1765630 bytes, checksum: 7421b5f67d41e9a6d29e4c7abd2d5fdf (MD5) Previous issue date: 2014 / Resumo: Objetivos: Avaliar os efeitos da acupressão no ponto Sanyinjiao (BP6) sobre a dor na primeira fase do trabalho de parto, o consumo de drogas analgésicas e analgesias/anestesias, o incômodo pelo tratamento recebido, o tempo de trabalho de parto, a taxa de cesárea o índice de Apgar no 1º e 5º minuto do recém-nascido e a satisfação pessoal em utilizar o tratamento entre os grupos. Método: Trata-se de um ensaio clínico controlado e randomizado, de caráter pragmático, com características simples-cego na avaliação da dor e duplo-cego nos desfechos de tempo de trabalho de parto e taxa de cesárea. Foram selecionadas 156 gestantes, com ? 37 semanas, dilatação cervical ? 4 cm e ? 2 contrações em 10 minutos, divididas em três grupos por meio de uma lista de números aleatórios, em um hospital universitário do interior do estado de São Paulo, Brasil, para receber acupressão, placebo ou participar como controle. Todas as participantes foram orientadas e estimuladas a realizar uma técnica de exercício respiratório e relaxamento muscular. A acupressão foi aplicada no ponto BP6 e a intensidade da dor avaliada por uma Escala Analógica e Visual (EAV) antes do tratamento, imediatamente (20 minutos) e 1 hora após o tratamento. Resultados: A média do escore de dor da EAV não foi diferente nos três grupos na admissão (p=0.0929), porém, as diferenças se fizeram imediatamente (p=<0.0001) e com 1 hora após o tratamento (p=<0.0001) de forma significativa entre os grupos. O incomodo do tratamento foi pequeno, informado por três participantes do grupo BP6. A média de duração do trabalho de parto apresentou diferença significativa nos três grupos a partir do tratamento até o nascimento do neonato (p=0.0047). A taxa de cesárea não mostrou diferença entre os grupos (p=0.2526) nem a avaliação de Apgar no primeiro e quinto minuto de vida do neonato (p=0.7218). O uso de analgésicos, anestesias e a satisfação pessoal do tratamento oferecido para um provável uso no futuro foram homogêneos entre os grupos, porém, a recordação sobre o alívio da dor durante o trabalho de parto foi maior no grupo acupressão BP6 (p=0.0018). Não houve diferença no uso de ocitocina (p=0.0521) e prostaglandina (p=0.9801), embora as participantes do grupo controle recebessem no total menos indução durante o trabalho de parto (p=0.0065). Conclusões: A acupressão no ponto BP6 se mostrou uma medida útil no alívio da dor, complementar para conduzir o trabalho de parto, encurtando este período, não invasiva e uma via de melhorar a qualidade dos cuidados à parturiente, sem ocasionar efeitos adversos para mãe ou para o neonato, entretanto, não houve diferença na taxa de cesárea neste estudo / Abstract: Purposes: To evaluate the effects of applying acupressure at the Sanyinjiao point (SP6) on pain in the first stage of labor, the use of analgesic drugs and anesthetics, the discomfort from the treatment received, delivery time in women in labor, the cesarean section rate, Apgar score at 1st and 5th minute of newborn, and personal satisfaction in using the treatment offered among groups. Method: The study design was a randomized controlled clinical trial of pragmatic character using a single-blind method to the evaluation of pain and a double-blinded for delivery time and cesarean section rate. 156 pregnant women were selected, with ? 37 weeks, cervical dilatation ? 4 cm and ? 2 contractions in 10 minutes, randomly divided into three groups in a university hospital in the state of São Paulo, Brazil. The women received acupressure, placebo or received standard care (control group). All of them were guided and stimulated to perform a technique of breathing exercises and muscle relaxation. The intervention was applied at the point SP6 and pain intensity was assessed by Visual Analog Scale (VAS) before the treatment, immediately (20 minutes) and 1 hour after the treatment. Results: The average pain score of VAS was no different in the three groups at baseline (p=0.0929), but the difference was immediately made (p=<0.0001) and at 1 hour after treatment (p=<0.0001) significantly between groups. The discomfort of treatment was small, reported by three participants in the SP6 group. The average duration of labor showed significant difference among the three groups, from the treatment until the birth (p=0.0047). The cesarean section rate showed no difference between the groups (p=0.2526) or the assessment of Apgar at the first and fifth minute of the newborn's life (p=0.7218). The use of analgesics, anesthetics and personal satisfaction of treatment offered for probable future use were homogeneous between the groups, but the memory on the reduction of pain during labor was greater in the acupressure group SP6 (p =0.0018). There was no difference in the use of oxytocin (p=0.0521) and prostaglandin (p=0.9801), although the participants in the control group received total less induction during labor (p=0.0065). Conclusions: The acupressure point SP6 showed a helpful measure to relieve pain, complementary to induce labor, shortening this period, non-invasive and a way of improving the quality of care the patient received without causing adverse effects to the mother or the newborn. However, there was no difference in cesarean section rate in this study / Mestrado / Enfermagem e Trabalho / Mestre em Ciências da Saúde

Masters in Public Administration - MPA / Community participation and awareness in disaster risk management is widely recognized as a cornerstone for disaster risk reduction and effective response and recovery strategies. This goes parallel with the world paradigm shift form relief and response to prevention and mitigation. There is gradually increase of fire and floods in informal settlements and Khayelitsha TR- Section in particular. “From 1995-2005 more than 8554 informal dwelling fire incidents occurred in Cape Town alone, affecting 40 558 households and around 160 000 peoples" (DiMP, 2008). And in 2007 alone floods affected 8,000 households and 38 residents in the Cape Town informal settlement of Khayelitsha; Bongani TR-Section and Phillippi; Phola park (Bouchard et al, 2007). This study analyzed community participation and awareness mechanisms in disaster risk management, its implementation, practice and effectiveness, following the promulgation of the Disaster Management Act No 57 of 2002, taking Khayelitsha TR- Section as a case study. In order to achieve the stated objectives, the researcher employed a combination of both qualitative and quantitative research paradigms. In qualitative context semi-structured interviews were conducted with the key informants disaster management officials and Khayelitsha TR-Section ward structure officials. Quantitative method, 100 structured questionnaires were distributed to Khayelitsha TR-Section residents. Using Khayelitsha TR- Section as a case study the thesis argues that despite the enabling policy and resource allocation for community participation and awareness its implementation proved to be a failure. Most of the mechanisms directed by the act are not implemented and those implemented its practice is not effective to achieve its stated objectives of risk reduction and effective response and recovery to disaster incidents. The study reviewed literature and theories of community participation and awareness in disaster risk management. It reviewed and outlined a policy framework and institutional arrangement for community participation and awareness in disaster risk management in accordance with the Disaster Management Act (No 57 of 2002). It further determined the level of community participation and awareness mechanism implementation. Records the level of community awareness and understanding, it determines the effectiveness of community participation and awareness mechanisms and finally based on the empirical results, literature reviews and theories, the study provides a number of recommendations to enhance and improved of community participation and awareness to disaster risk management officials and policy makers.

Orientador: Rodney Carlos Bassanezi / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica / Made available in DSpace on 2018-08-27T16:18:31Z (GMT). No. of bitstreams: 1 Dias_AlbertoFaustino_M.pdf: 1122688 bytes, checksum: a62e35c5bae8f636d723761c61dcfcd7 (MD5) Previous issue date: 2015 / Resumo: Apresentamos neste trabalho, uma relação existente entre a despretensiosa Sequência de Fibonacci e o Número de Ouro, conhecido também como Razão Áurea ou Número Áureo. Neste mesmo contexto, tratamos de um modelo variacional discreto através das Equações de Diferenças e contínuo através das Equações Diferenciais Lineares, problematizado pelo crescimento populacional de escargots, em cuja solução aparece o Número de Ouro. Para fundamentação deste trabalho utilizamos pesquisa bibliográfica constituída de livros e publicações diversas, cujo embasamento reside principalmente nos autores, Rodney C. Bassanezzi, Maurício Zahn, William E. Boyce e Richard C. Diprima. O princial objetivo deste trabalho foi dar uma abordagem contínua ao modelo variacional discreto gerado pelo crescimento populacional dos escargots / Abstract: In this work, an existing relationship between the unpretentious Fibonacci sequence and the Golden Mean, also known as the Golden Ratio or Golden Number. In this same context, we deal with a discrete variational model through the differences and continuous equations through Linear Differential Equations, questioned by population growth escargots, whose solution appears the Golden Mean. For reasons of this work we use literature consists of books and publications whose foundation lies mainly in authors, Rodney C. Bassanezzi, Mauritius Zahn, William E. Boyce and Richard C. DiPrima. The princial objective was to give a continuous approach to the discrete variational model generated by population growth of snails / Mestrado / Matematica Aplicada e Computacional / Mestre em Matemática Aplicada e Computacional

The increasing demand of renewable energy is the big driving force for the research and development of more efficient solar energy conversion solutions. Solar cells, which use the photovoltaic effect to convert the photon energy to electrical current, are an important solar energy conversion technique. One solar cell technology is thin-film solar cells. Thin-film solar cells use an absorption layer with a direct band gap. A direct band gap has the advantage that the photons will penetrate less deep until a photoexcitation occur compared to semiconductors with an indirect band gap (e.g. silicon). For this reason the thin-film solar cells can be made very thin.CIGS is a common thin-film solar cell absorber material containing copper (Cu), indium (In), gallium (Ga) and selenium (Se). One objective of this work has been to determine element concentrations of CIGS absorption layers from sample measurements. The GGI ratio determines the band gap, which is an important factor for optimising the efficiency of the solar cell.1 The copper vacancy is the main acceptor dopant in CIGS. The Cu concentration has shown to be important for the efficiency and for other properties of the absorber [2].The measuring technique used in this work has been photoelectron spectroscopy (PES). PES produces a spectrum showing distinct peaks corresponding to electron binding energy levels for specific element subshells. Measurements with different photon energies have been performed on samples with and without post deposition treatment (PDT). A great deal of the effort has been to calculate relative element concentrations based on the PES peak intensities. Two important parameters when performing the calculations are the photoionization cross section (including the angular dependence of the cross section) and the inelastic mean free path of the photoelectrons.The results show that the GGI and the corresponding band gap will be almost the same with and without PDT except for close to the surface where PDT lowers the GGI.The calculations showed that the copper concentration is lowest at the surface. Moreover, PDT with RbF results in lower copper concentration closer to the junction.The results show a discrepancy of the GGI and CGI ratios when using the angular dependent cross sections in [10] and [11] compared to using the cross sections in [6] and [7]. / Det ökande behovet av förnybar energi gör att forskning och utveckling av solenergilösningar är av största vikt. Solceller, vilka utnyttjar den fotovoltaiska effekten, är den vanligaste tekniken för omvandling av solenergi till elektricitet. Tunnfilmssolceller är en typ av solceller vars absorbent har ett direkt bandgap, till skillnad från kisel som har ett indirekt bandgap. Fördelen med ett direkt bandgap är att det ljusabsorberande materialet kan göras mycket tunt.En vanlig tunnfilmssolcell är CIGS. Det är en komposit bestående av koppar (Cu), indium (In), gallium (Ga) och selen (Se). Ett syfte med detta självständiga arbete har varit att beräkna koncentrationerna av de ingående ämnena i halvledarskiktet av CIGS. GGI-kvoten bestämmer bandgapet, vilket är en viktig faktor för solcellens verkningsgrad. Kopparvakansen är den huvudsakliga halvledaracceptorn i CIGS. Kopparkoncentrationen har visat sig vara viktig för bl.a. solcellens verkningsgrad [2].Mättekniken som används i detta arbete kallas fotoelektronspektroskopi (PES). PES-mätningar ger ett spektrum där spektrallinjerna representerar olika nivåer av elektroners bindningsenergi för olika grundämnen. Mätningar med olika fotonenergier, på prover med och utan ytbehandling (PDT), har utförts. En stor del av arbetet har varit att beräkna relativa koncentrationer av de olika grundämnena från spektrallinjerna i spektrumet. Viktiga parametrar som man behöver ta hänsyn till i uträkningarna är sannolikheten för en fotoemissionsprocess hos fotonerna, vinkelberoendet och den fria medelväglängden hos fotoelektronerna.Resultaten visar att GGI-kvot och bandgap blir nästan detsamma med eller utan PDT, förutom närmast ytan där PDT minskar GGI-kvoten.Resultaten visar också att kopparkoncentrationen är lägst på ytan och att PDT med RbF minskar kopparkoncentrationen närmast ytan.Resultaten visar att det blir skillnader mellan GGI- och CGI-kvoterna beroende på om beräkningarna baserats på vinkelberoende träffytor enligt [10] och [11] eller baserats på träffytor enligt [6] och [7].

A Topological Interlocking Configuration (TIC) is an assembly where the shape and alignment of the blocks define the kinematic constraints. Conventional TICs are single-layered structures made of convex blocks. The interface between the blocks in an assembly is face-to-face contact. The traditional convention disregards the use of joinery, adhesive, or other mechanisms that keep two pieces next to each other. However, TICs require a support structure that prevents the lateral strain of the blocks.<br><br>The generation process of a TIC starts with a surface tessellation that describes a geometric domain. Each tile in the tessellation represents a traversal section of a block. For regular tessellations and uniform generation parameters, such sections lie in the middle of their respective blocks. Additionally, such conditions guarantee the blocks align adequately with each other. If one of such conditions does not hold, then the resultant blocks may not be aligned. Furthermore, there could be overlapping between the blocks, which makes a TIC invalid.<br><br>Traditionally, the generation parameters are angle values set at the edges of the tiles. The angles must match between tiles such that each block in the assembly has a geometry that imposes kinematic constraints to its neighboring blocks. Using the same angle values on regular and semi-regular tessellation produces feasible blocks. That is not the case for non-regular tessellations, curvilinear surfaces, and free-form 3D meshes. In such cases, the generation method must find specific angle values to design the blocks and reduce overlapping.<br><br>In this thesis, we propose a TIC generation framework focused on the generation of valid interlocking assemblies based on multiple types of surface tessellations. We start with the Height-Bisection method, a TIC generation approach that uses the distances from a tile to its respective evolution sections as the generation parameters. The method considers the bisector vectors between two tiles to define the parameters that generate aligned blocks to each other. We expand the generation model to a complete pipeline process that finds feasible generation parameters. The pipeline includes clipping parameters and methods in case that overlapping between blocks cannot be avoided.<br><br>Additionally, we describe a generalization of the mid-section evolution concept to include multiple evolution steps during the generation process. Our approach considers the angles and distances required to generate infinitely many TICs, including shapes that are not possible using the traditional generation method and the Height-Bisection method. Finally, we consider the interlocking assemblies that cannot maintain static equilibrium due to the shape of the surface tessellation. We consider the Structure Feasibility Analysis method to find the location and magnitude of the minimum tension forces that guarantee a TIC will reach a static equilibrium state. We describe how to update the generation parameters according to the results of the feasibility analysis. Our results show that the proposed pipeline generates valid TICs based on different surface tessellations, including closed and free-form shapes.

abstract: Within the past two decades, metasurfaces, with their unique ability to tailor the wavefront, have attracted scientific attention. Along with many other research areas, RADAR cross-section (RCS)-reduction techniques have also benefited from metasurface technology. In this dissertation, a novel technique to synthesize the RCS-reduction metasurfaces is presented. This technique unifies the two most widely studied and two well-established modern RCS-reduction methods: checkerboard RCS-reduction andgradient-index RCS-reduction. It also overcomes the limitations associated with these RCS-reduction methods. It synthesizes the RCS-reduction metasurfaces, which can be juxtaposed with almost any existing metasurface, to reduce its RCS. The proposed technique is fundamentally based on scattering cancellation. Finally, an example of the RCS-reduction metasurface has been synthesized and introduced to reduce the RCS of an existing high-gain metasurface ground plane. After that, various ways of obtaining ultrabroadband RCS-reduction using the same technique are proposed, which overcome the fundamental limitation of the conventional checkerboard metasurfaces, where the reflection phase difference of (180+-37) degrees is required to achieve 10-dB RCS reduction. First, the guideline on how to select Artificial Magnetic Conductors (AMCs) is explained with an example of a blended checkerboard architecture where a 10-dB RCS reduction is observed over 83% of the bandwidth. Further, by modifying the architecture of the blended checkerboard metasurface, the 10-dB RCS reduction bandwidth increased to 91% fractional bandwidth. All the proposed architectures are validated using measured data for fabricated prototypes. Critical steps for designing the ultrabroadband RCS reduction checkerboard surface are summarized. Finally, a broadband technique to reduce the RCS of complex targets is presented. By using the proposed technique, the problem of reducing the RCS contribution from such multiple-bounces simplifies to identifying and implementing a set of orthogonal functions. Robust guidelines for avoiding grating lobes are provided using array theory. The 90 degree dihedral corner is used to verify the proposed technique. Measurements are reported for a fabricated prototype, where a 70% RCS-reduction bandwidth is observed. To generalize the method, a 45 degree dihedral corner, with a quadruple-bounce mechanism, is considered. Generalized guidelines are summarized and applied to reduce the RCS of complex targets using the proposed method. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2020

Laser diagnostics are fast-response, non-intrusive and species-specific tools perfectly applicable for studying combustion processes. Quantitative measurements of species concentration and temperature require spectroscopic data to be well-known at combustion-relevant conditions. Absorption cross-section is an important spectroscopic quantity and has direct relation to the species concentration. In this work, the absorption cross-sections of basic hydrocarbons are measured using Fourier Transform Infrared (FTIR) spectrometer, tunable Difference Frequency Generation laser and fixed wavelength helium-neon laser. The studied species are methane, methanol, acetylene, ethylene, ethane, ethanol, propylene, propane, 1-butene, n-butane, n-pentane, n-hexane, and n-heptane. The Fourier Transform Infrared (FTIR) spectrometer is used for the measurements of the absorption cross-sections and the integrated band intensities of the 13 hydrocarbons. The spectral region of the spectra is 2800 – 3400 cm-1 (2.9 – 3.6 μm) and the temperature range is 673 – 1100 K. These valuable data provide huge opportunities to select interference-free wavelengths for measuring time-histories of a specific species in a shock tube or other combustion systems. Such measurements can allow developing/improving chemical kinetics mechanisms by experimentally determining reaction rates. The Difference Frequency Generation (DFG) laser is a narrow line-width, tunable laser in the 3.35 – 3.53 μm wavelength region which contains strong absorption features for most hydrocarbons due to the fundamental C-H vibrating stretch. The absorption cross-sections of propylene are measured at seven different wavelengths using the DFG laser. The temperature range is 296 – 460 K which is reached using a Reflex Cell. The DFG laser is very attractive for kinetic studies in the shock tube because of its fast time response and the potential possibility of making species-specific measurements. The Fixed wavelength helium-neon (HeNe) laser at 3.39 μm is used to measure the absorption cross-section of the fuels mentioned above. The dependence on temperature, pressure and bath gas (helium, argon and nitrogen) is also examined. The temperature and pressure ranges of this study are 296 – 800 K and 250 – 1000 Torr, respectively. These are the first measured cross-sections at HeNe laser wavelength that are applicable at combustion-relevant conditions.

L’étude du processus Drell-Yan, ou la production dans des collisions entre hadrons à haute énergie d’une paire de leptons par l’intermédiaire d’un boson Z ou ɣ virtuel, est un moyen privilégié pour comprendre les mécanismes de production de particules massives comme le boson de Higgs. Dans cette thèse, les données collectées en 2016 par l’expérience CMS dans les collisions proton-proton à une énergie de 13 TeV dans le système du centre de masse, correspondant à une luminosité intégrée de 36,3 fb⁻¹, sont utilisées pour réaliser une mesure de précision de section efficaces du processus Drell-Yan différentielles en l’impulsion transverse de la paire de leptons, pour des masses invariantes de la paire allant de 50 à 1000 GeV.La mesure utilise les canaux comprenant deux électrons ou deux muons, qui ont l’avantage d’être aisément identifiables expérimentalement et, ainsi, de permettre des mesures précises de sections efficaces. Au total, environ dix millions d’événements comprenant deux électrons et vingt millions d’événements comprenant deux muons sont analysés. L’extension de l’analyse précédente de la collaboration CMS, limitée en masse invariante à l’intervalle entre 76 et 106 GeV, requiert un meilleur contrôle des bruits de fond, plus importants en-dessous de 76 et au-dessus de 106 GeV que dans l’intervalle précédemment considéré. La contribution dominante, la production d’une paire de quarks top se désintégrant en leptons, est étudiée en détail, ainsi que la contamination des données par des électrons mal identifiés. Après prise en compte de l’efficacité de détection, les résultats obtenus dans les deux canaux sont compatibles et sont combinés en une unique mesure.La précision obtenue, de l’ordre du pourcent, dans des régions jusqu’ici peu explorées permet d’obtenir de nouvelles contraintes sur des modèles largement utilisés en physique des particules. À cette fin, la mesure est comparée à six prédictions illustrant différentes approches pour la prédiction du spectre en impulsion transverse. Malgré d’assez bonnes performances générales, aucune d’entre elles ne permet une description complète des données après prise en compute des incertitudes théoriques et expérimentales. C’est en particulier le cas à grande masse invariante ou lorsqu’un jet est identifié dans l’état final. Certaines approches encore peu répandues obtiennent de meilleurs résultats dans les régions qu’elles visent spécifiquement. De nouveaux développements théoriques seront nécessaires pour combiner celles-ci afin d’obtenir des prédictions fiables dans l’ensemble de l’espace des phases. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished