Multi-frequency Raman Generation (MRG) has been achieved in the transient regime excited by dual-wavelength chirped pump pulses. Spectral phase interferometry for direct electric-field reconstruction (SPIDER) technique is used to study the group velocity dispersion (GVD) of MRG. A few changes have been applied to the SPIDER set-up to adapt it to the multi-color but narrow-bandwidth pulses. The phase of orders from the 1st Stokes order through to the 1st anti-Stokes order are measured. The technique is applied on the study of phase dependency of the 1st anti-Stokes orders on frequency tuning through the Raman transition.

Multi-frequency Raman Generation (MRG) has been achieved in the transient regime excited by dual-wavelength chirped pump pulses. Spectral phase interferometry for direct electric-field reconstruction (SPIDER) technique is used to study the group velocity dispersion (GVD) of MRG. A few changes have been applied to the SPIDER set-up to adapt it to the multi-color but narrow-bandwidth pulses. The phase of orders from the 1st Stokes order through to the 1st anti-Stokes order are measured. The technique is applied on the study of phase dependency of the 1st anti-Stokes orders on frequency tuning through the Raman transition.

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Estatística, Programa de Pós-Graduação em Estatística, 2015. / Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-03-24T13:44:21Z No. of bitstreams: 1 2015_RaquelAraújodeAlmeida.pdf: 4445488 bytes, checksum: 710ab230eeeec1cf3e7badbab7edc655 (MD5) / Approved for entry into archive by Marília Freitas(marilia@bce.unb.br) on 2016-05-26T16:28:35Z (GMT) No. of bitstreams: 1 2015_RaquelAraújodeAlmeida.pdf: 4445488 bytes, checksum: 710ab230eeeec1cf3e7badbab7edc655 (MD5) / Made available in DSpace on 2016-05-26T16:28:35Z (GMT). No. of bitstreams: 1 2015_RaquelAraújodeAlmeida.pdf: 4445488 bytes, checksum: 710ab230eeeec1cf3e7badbab7edc655 (MD5) / O presente trabalho tem como objetivo propor um método alternativo de pontuação para as questões do tipo A das provas do vestibular da UnB elaboradas pelo CEBRASPE. Esse novo método de pontuação consiste em aplicar o Modelo de Resposta Gradual (MRG), da Teoria da Resposta ao Item, ao considerar como uma alternativa de resposta a “não resposta” do aluno às questões do tipo A das provas do vestibular da UnB, nas quais os indivíduos ganham um ponto ao acertarem a questão, perdem um ponto ao errarem a questão e ganham zero pontos por não responderem a questão. Este método de pontuação foi proposto com o intuito de melhorar a avaliação dos indivíduos, visto que a teoria da resposta ao item apresenta inúmeras vantagens em relação ao método convencionalmente utilizado pelo CEBRASPE. Os resultados mostraram uma alta proximidade das notas estimadas pelo modelo de resposta gradual e das notas obtidas pelo método convencional. Dessa forma, pôde-se concluir que o método proposto é eficiente em avaliar os indivíduos com o aditivo das vantagens que a Teoria da Resposta ao Item oferece. Porém, tanto os resultados como algumas limitações evidenciaram oportunidades futuras de pesquisas sob a proposta apresentada, ainda não exaustivamente exploradas. / This paper aims to propose an alternative scoring method for questions of type A of the UnB vestibular entrance exam prepared by CEBRASPE. This new correction method applies the Graded Response Model (GRM) from Item Response Theory. We consider “no answer” as an additional response class to the regular possibilities “right” or “wrong”. in the UnB vestibular entrance exam, individuals score 1 for each question with right answer, -1 for each question with wrong answer, and 0 for no answer. This scoring method has been proposed in order to improve the evaluation of individuals' proficiencies, as the item response theory has many advantages compared to the conventional method used by CEBRASPE. The results showed a high correlation between the scores obtained with the use of the graded response model and the scores given by the conventional method. We concluded that the proposed method is effective in evaluating individuals' proficiencies with the advantages of the Item Response Theory. However, the results show opportunities for future research in the studied problem.

L’objectif de cette thèse était de synthétiser des multicouches à base de couches ferromagnétiques GeMn qui sont empilées et séparées par des couches de Ge en utilisant la technique d'épitaxie par jets moléculaires.Outre de nombreuses applications en spintronique issues de cette structure de matériaux, la réalisation de capteurs biochimiques dédiés à la détection moléculaire est l’idée directrice de ce travail. Un tel dispositif présenterait les atouts que ses matériaux constituants apportent : haute sensibilité, sélectivité et compatibilité parfaite avec la technologie de Si-Ge. Dans la première partie de ce manuscrit sont présentés les résultats obtenus de la croissance d’hétérostructures Mn5Ge3, Mn5Ge3Cx sur Ge(111) puis la reprise d’épitaxie de la barrière de Ge sur Mn5Ge3, la première étape avant la croissance de la deuxième couche ferromagnétique. Nous avons également analysé les propriétés structurales et magnétiques de ces couches minces ainsi que les dificultés dues à la croissance de la couche de Ge, notamment la diffusion et la ségrégation. Deux approches utilisant le carbone ont été proposées pour réduire la ségrégation : barrière de diffusion en carbone et remplissage des sites interstitiels du réseau Mn5Ge3 par du carbone. Le second axe alternatif pour la synthèse est consacré à la croissance de la structure colonnaire empilée Ge1-xMnx. Les conditions pour obtenir la structure colonnaire ont été déterminées. Les propriétés structurales et mesures magnétiques ont montré que cette phase était particulièrement intéressant dans la famille des semiconducteurs ferromagnétiques dilués à base de Ge-Mn pour les applications en spintronique et croissance de multicouches. La reprise d’épitaxie de plusieurs couches ferromagnétiques séparées par Ge a été effectuée et l’étude du couplage magnétique a été également menée. Enfin, nous présentons les premiers résultats sur le greffage de porphyrines et de protéines sur diverses surfaces hydrophiles et hydrophobes (Si, Ge), permettant d’accéder aux études de la faisabilité des capteurs Ge/GeMn. L’ensemble de ce travail indique que les multicouches de Ge/GeMn apparaissent comme des candidats à fort potentiel pour la spintronique, notamment pour capteurs bio-chimiques dans les semi-conducteurs du groupe IV. / The objective of this thesis is to synthetize the multilayers based on the sandwiched structure of GeMn ferromagnetic layers by mean of Molecular Beam Epitaxy on Ge substrate. Applications in spintronic field from this study are potential such as structures of spin valves, nanoscale sensors devoted to the detection of biochemical molecules. We actually focus on the biochemical sensors based on GMR (or TMR) phenomenon in stacking layered structure. These devices offer many advantages that the constituent materials may provide : high sensibility, selectivity, and especially, compatibility with Si-Ge technology. The first part of this manuscript presents the results obtained of heterostructure growth of Mn5Ge3, Mn5Ge3Cx on Ge(111), then Ge overgrowth on Mn5Ge3, the first step to study multilayers growth. Also, we have discussed about the structural and magnetic properties of these thin films as well as the problems due to the growth of multilayers, especially the diffusion and segregation. The approaches to reduce the diffusion were proposed by introducing carbon atoms as diffusion barrier or by fulfilling insterstial sites of Mn5Ge3 lattice by carbon atoms. The second axis of materials synthesis is devoted to the growth of multilayers Ge1-xMnx nanocolumn structure. The growth condition of Ge1-xMnx nanocolumns has been determined. We have studied structural and magnetic properties of this phase which are of particular interest to spintronic applications and multilayers growth. The Ge/Ge1-xMnx nanocolumns multilayers have been done and the interlayer exchange coupling between ferromagnetic layers has been studied. Finally, we have presented the preliminary results of porphyrin molecules and protein grafting on hydrophilic and hydrophobic surfaces (Si and Ge). This allows accessing to study the feasibility of Ge/GeMn-based sensors. This work indicates that the Ge/GeMn mutilayers appear to be a potential candidate for spintronics and biochemical sensors in the group IV semi-conductors.

Climatological winds over the equatorial Indian Ocean (EqlO) are westerly most of the year. Twice a year, in April-May ("spring") and October-December ("fall"), strong, sustained westerly winds generate eastward equatorial jets in the ocean. There are several unresolved issues related to the equatorial jets. They accelerate rapidly to speeds over lms"1 when westerly wind stress increases to about 0.7 dyne cm"2 in spring and fall, but decelerate while the wind stress continues to be westerly; each jet is followed by westward flow in the upper ocean lasting a month or longer. In addition to the semi-annual cycle, the equatorial winds and currents have strong in-traseasonal fluctuations. Observations show strong 30-60 day variability of zonal flow, and suggest that there might be variability with periods shorter than 20 days in the central EqlO. Observations from moored current meter arrays along 80.5°E south of Sri Lanka showed a distinct 15 day oscillation of equatorial meridional velocity (v) and off-equatorial zonal velocity (u). Recent observations from current meter moorings at the equator in the eastern EqlO show continuous 10-20 day, or biweekly, oscillations of v. The main motivation for the present study is to understand the dynamics of intraseasonal variability in the Indian Ocean that has been documented in the observational literature. What physical processes are responsible for the peculiar behavior of the equatorial jets? What are the relative roles of wind stress and large scale ocean dynamics? Does intraseasonal variability of wind stress force intraseasonal jets? What is the structure and origin of the biweekly variability? The intraseasonal and longer timescale variability of the equatorial Indian Ocean circulation is studied using an ocean general circulation model (OGCM) and recent in Abstract ii situ observations. The OGCM simulations are validated against other available observations. In this thesis, we document the space-time structure of the variability of equatorial Indian Ocean circulation, and attempt to find answers to some of the questions raised above. The main results are based on OGCM simulations forced by high frequency reanalysis and satellite scatterometer (QuikSCAT) winds. Several model experiments with idealized winds are used to interpret the results of the simulations. In addition to the OGCM simulations, the origin of observed intraseasonal anomalies of sea surface temperature (SST) in the eastern EqlO and Bay of Bengal, and related air-sea interaction, are investigated using validated satellite data. The main findings of the thesis can be summarized as: • High frequency accurate winds are required for accurate simulation of equatorial Indian Ocean currents, which have strong variability on intraseasonal to interannual time scales. • The variability in the equatorial waveguide is mainly driven by variability of the winds; there is some intraseasonal variability near the western boundary and in the equatorial waveguide due to dynamic instability of seasonal "mean" flows. • The fall equatorial jet is generally stronger and longer lived than the spring jet; the fall jet is modulated on intraseasonal time scales. Westerly wind bursts can drive strong intraseasonal equatorial jets in the eastern EqlO during the summer monsoon. • Eastward equatorial jets create a westward zonal pressure gradient force by raising sea level, and deepening the thermocline, in the east relative to the west. The zonal pressure force relaxes via Rossby wave radiation from the eastern boundary. • The zonal pressure force exerts strong control on the evolution of zonal flow; the decel eration of the eastward jets, and the subsequent westward flow in the upper ocean in the presence of westerly wind stress, is due to the zonal pressure force. • Neither westward currents in the upper ocean nor subsurface eastward flow (the ob served spring and summer "undercurrent") requires easterly winds; they can be gener ated by equatorial adjustment due to Kelvin (Rossby) waves generated at the western (eastern) boundary. • The biweekly variability in the EqlO is associated with forced mixed Rossby-gravity (MRG) waves generated by intraseasonal variability of winds. The biweekly MRG wave in has westward and upward phase propagation, zonal wavelength of 3000-4500 km and phase speed of 4 m s"1; it is associated with deep off equatorial upwelling/downwelling. Intraseasonal SST anomalies are forced mainly by net heat flux anomalies in the central and eastern EqlO; the large northward propagating SST anomalies in summer in the Bay of Bengal are due to net heat flux anomalies associated with the monsoon active-break cycle. Coherent variability in the atmosphere and ocean suggests air-sea interaction.

This thesis deals with messaging and integration of third-party JMS providers into JBoss application server. The aim of the thesis was to design and implement a general-purpose testsuite to verify the proposed integration. First requirement was to get familiar with key technologies for integration including Java Message Service, Java EE Connector Architecture, selected JMS providers and JBoss AS. Specific procedures of integration were designed and described for JMS providers Apache ActiveMQ, IBM WebSphere MQ and Red Hat MRG Messaging. The testsuite implemented to verify the functionlity of the integration focuses on four areas - transactions, clustering, high availibility and performance. The process of testing was automated using continuous integration tool Jenkins. Finally the test application was used to evaluate functionality of the integration and compare different JMS providers and various versions of JBoss AS.