Orientador: Renata Junqueira de Souza / Banca: Maria de Lourdes Zizi Trevizan Peres / Banca: José Batista de Sales / Resumo: Esta pesquisa, realizada no Curso de Mestrado em Educação da UNESP, como parte dos estudos que enfocam as práticas educativas e a formação de professores, incluída a avaliação de procedimentos educacionais no contexto de ensino, teve como objetivo analisar o sistema de avaliação elaborado pela Secretaria de Educação do Estado de São Paulo, o SARESP, mais especificamente as provas referentes ao triênio 2003-2005 e aplicadas à 5ª série do ensino fundamental. Com base em teorias que trabalham com os conceitos de leitura, texto, interpretação, gêneros textuais e avaliação, os textos e as questões de interpretação selecionados e utilizados nas provas foram analisados, e a diversidade de gêneros textuais nelas presentes foi identificada. Nesta investigação optou-se pela abordagem qualitativa por ser a metodologia que apresenta as características necessárias para atingir os objetivos propostos. O estudo das provas incluiu uma análise documental e quantitativa dos tipos de textos presentes nas avaliações, e uma análise qualitativa desses textos e das questões de interpretação que os acompanham. Após o levantamento dos gêneros textuais selecionados para as versões do SARESP escolhidas para este estudo, eles foram classificados como textos artísticos e não artísticos, ficando evidenciada a predominância dos primeiros. Quanto às questões das provas, observaram-se exemplos de exercícios redundantes e mal elaborados, que acabam por dificultar a leitura e a interpretação dos textos. Concluída a análise, ressalta-se a urgência de algumas reformulações nesse instrumento oficial de avaliação, tendo em vista o impacto de seus resultados no interior das escolas e, mais especificamente, na conformação de seus currículos. / Abstract: This research, developed in the Education Master course of UNESP as a part of the studies that focus in the educative practices and teachers formation, including the evaluation of educational methods in the teaching context, had as objective to analyze the evaluation system elaborated by the Education Clerkship of the São Paulo State, called SARESP, specifically the tests applied to the fifth level of the primary education, during the period of 2003-2005. Based on theories about concepts of lecture, text, interpretation, textual genres and evaluation, the texts and interpretation questions used in the tests were selected for analyses, identifying the diversity of text genres insert on them. In this investigation it was opted to use the qualitative boarding since this methodology presents the necessary characteristics to the concretization of the proposed objectives. The study of the tests included a documental and qualitative analyses of the type of the tests in the evaluations, and qualitative analyses of the interpretation questions that accompany the texts. The textual genres selected in the different versions of SARESP were classified as artistic and non-artistic texts, being evident the predominance of the first ones. In relation to the tests questions, it was observed some redundant exercise examples also containing elaboration deficiency, what difficult the lecture and interpretation of the texts. Thus, it is important to evidence the urgency of some reformulations in this official evaluation instrument, taking into account the possible impact of its results in the school environment and, more specifically, in the curriculum elaboration. / Mestre

Planetesimals may form from the gravitational collapse of dense particle clumps initiated by the streaming instability. We use simulations of aerodynamically coupled gas-particle mixtures to investigate whether the properties of planetesimals formed in this way depend upon the sizes of the particles that participate in the instability. Based on three high-resolution simulations that span a range of dimensionless stopping times 6 X 10(-3) <= tau <= 2, no statistically significant differences in the initial planetesimal mass function are found. The mass functions are fit by a power law, dN/dM(p) proportional to M-p(-p), with p = 1.5-1.7 and errors of Delta p approximate to 0.1. Comparing the particle density fields prior to collapse, we find that the high-wavenumber power spectra are similarly indistinguishable, though the large-scale geometry of structures induced via the streaming instability is significantly different between all three cases. We interpret the results as evidence for a near-universal slope to the mass function, arising from the small-scale structure of streaming-induced turbulence.

No description available.

Stars form from collapsing massive clouds of gas and dust. The UV and optical light emitted by a forming or recently-formed star is absorbed by the surrounding cloud and is re-radiated thermally at infrared and submillimetre wavelengths. Observations in the submillimetre spectrum are uniquely sensitive to star formation in the early Universe, as the peak of the thermal emission is redshifted to submillimetre wavelengths. The coolest objects in star forming regions in our own Galaxy, including heavily-obscured proto-stars and starless gravitationally-bound clumps, are also uniquely bright in the submillimetre spectrum. The Earth's atmosphere is mostly opaque at these wavelengths, however, limiting the spectral coverage and sensitivity achievable from ground-based observatories. The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) observes the sky from an altitude of 40 km, above 99.5% of the atmosphere, using a long-duration scientific balloon platform. BLAST observes at 3 broad-band wavelengths spanning 250-500 micron, taking advantage of detector technology developed for the space-based instrument SPIRE, scheduled for launch in 2008. The greatly-enhanced atmospheric transmission at float altitudes, increased detector sensitivity and large number of detector elements allow BLAST to survey much larger fields in a much smaller time than can be accomplished with ground-based instruments. It is expected that in a single 10-day flight, BLAST will detect ~10000 extragalactic sources, ~100 times the number detected in 10 years of ground-based observations, and 1000s of Galactic star-forming sources, a large fraction of which are not seen by infrared telescopes. The instrument has performed 2 scientific flights, in the summer of 2005 and winter of 2006, for a total of 16 days of observing time. This thesis discusses the design of the instrument, performance of the flights, and presents the analysis of 2 of the fields observed during the first flight. A failure in the optical system during the first flight precluded sensitive extragalactic observations, so the majority of the flight was spent observing Galactic targets. We anticipate exciting extragalactic and Galactic results from the 2006 data. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Galaxy formation is one of the central problems of Physical Cosmology. Neutral hydrogen plays an important role, linking the collapse of cooling gas into haloes with the formation of stars. Lyman alpha, hydrogen's strongest spectral line, can directly probe neutral hydrogen in the high redshift Universe. Lyα can be observed in absorption in Damped Lyman Alpha systems (DLAs): high Hi column density regions that dominate the neutral gas content of the Universe between z ~ 0-5. Lyα in emission is an important signature of early, starforming galaxies. Both populations, however, present significant theoretical challenges. As part of my thesis, I have developed a Monte Carlo Lyα radiative transfer code to investigate models of early galaxies. Rauch et al. (2008) performed an ultra-deep spectroscopic survey and discovered a new population of very faint, spatially extended Lyα emitters, which they claimed to be the long-sought host galaxies of DLAs at z ~ 3. I show here that a simple analytical model, which reproduces the incidence rate and kinematics of DLAs in the context of λCDM models for structure formation, also reproduces the size distribution of the faint Lyα emitters for plausible parameters, which supports their identification as DLA host galaxies. The model suggests that galaxies in haloes with vc ~ 100-150 km s-1 account for the majority of DLA host galaxies, and that these galaxies at z ~ 3 are the building blocks of typical present-day galaxies like our Milky Way. I further use my newly developed Lyα code to perform detailed 1D radiative transfer calculations, investigating the spatial and spectral distribution of Lyα emission due to star formation at the centre of DLAs, and its dependence on the spatial and velocity structure of the gas. The modelling reproduces the observed properties of both DLAs and the faint Lyα emitters, including the velocity width and column density distribution of DLAs and the large observed spatial extent of the faint emitters. In the model, haloes hosting DLAs retain up to 20% of the cosmic baryon fraction in the form of neutral hydrogen. The scattering of Lyα photons at the observed radii, which can be as large as 50 kpc, requires the bulk velocity of the gas at the centre of the haloes to be moderate. I furthermore perform 3D Lyα radiative transfer simulations, building on numerical simulations of galaxy formation that include galactic winds and gas infall. The Lyα emission region is shown to be larger and smoother than the cross-section for damped absorption by ~ 50%, with Lyα photons scattered effectively by gas with column densities >~ 1017 cm⁻². The spectra typically show two peaks, with the relative strength of the red (blue) peak being a reflection of the relative contribution of outflow (inflow) in the velocity profile. There is considerable variation in the observed line profile and spectral intensity with viewing angle. These more realistic models support many of the simplifying assumptions of my previous models, and have the potential to probe the important role of galactic winds in protogalaxies. The main conclusion is that the faint population of Lyα emitters are indeed the long sought host population of DLAs. Ultra-faint observations of Lyα emission have exceptional potential to directly probe the spatial distribution and kinematics of neutral hydrogen in early galaxies.

Certains affirment qu’à l’avenir, un nombre croissant de traducteurs postéditeront des textes issus de la traduction automatique plutôt que de traduire. Cette étude examine le bagage à inculquer aux futurs traducteurs-postéditeurs pour mieux les outiller. Un sondage mené en ligne auprès de postéditeurs du Canada et d’ailleurs montre que les compétences traductionnelles et rédactionnelles sont les plus utiles en PÉ, suivies des compétences en correction et d’aspects profession¬nels; les connais¬sances spécialisées et les compétences en informatique arrivent aux derniers rangs. Le sondage montre de plus que si les compétences traductionnel¬les et rédactionnel¬les sont généralement acquises pendant la formation universitaire en traduction, ce n’est pas le cas des compétences en correction, et encore moins des aspects professionnels : deux éléments à intégrer en priorité à la formation des traducteurs-postéditeurs pour la bonifier. La thèse propose deux formules susceptibles de favoriser l’intégration des éléments prioritaires pour mieux préparer les traducteurs-postéditeurs de demain.

The first section of this thesis describes three model studies involving the synthesis of the divinylcyclopropanes (135), (136), and (137) and the subsequent thermal rearrangement of these compounds to provide the interesting tricyclic compounds (139), (140), and (141). [Formula Omitted] The second section of this thesis describes a formal total synthesis of the antitumor sesquiterpenoid (±)-quadrone (34). The synthesis is based on the chemistry developed in the model studies and involves the thermal rearrangement of the divinylcyclopropane (304) as the key step. The resulting product, compound (305), is- subsequently elaborated into the keto aldehyde (230), and since compound (230) has previously been converted into (t)-quadrone (34) by Burke and coworkers,¹⁰¹ the isolation of (230) comprises a formal total synthesis of the sesquiterpenoid. [Formula Omitted] The third section of this thesis describes a study involving the facile vinylmethylenecyclopropane rearrangement of enolates derived from various 7-exo-vinylbicyclo[4.1.0]heptan-2-ones. / Science, Faculty of / Chemistry, Department of / Graduate

Cette thèse est consacrée à l'exploitation des propriétés de non circularité et de non gaussianité des signaux en traitement d'antennes.Dans une première partie de cette thèse, nous nous intéressons au contexte de la formation de voies (beamforming) pour la réception d'un signal utile inconnu, dont le vecteur directionnel est connu, corrompu par un bruit potentiellement non circulaire et/ou non gaussien. Dans des études récentes, un beamformer MVDR (Minimum Variance Distortionless Response) linéaire au sens large WL (Widely Linear) exploitant la non circularité au second ordre (SO) des interférences a été introduit et analysé. Cependant, ce beamformer demeure sous optimal pour la réception d'un signal utile non circulaire au SO, du moment où il n'exploite pas la non circularité de ce dernier. C'est ainsi, que notre contribution a porté principalement sur l'introduction, l'étude de performances et la mise en \oe uvre d'un beamformer MVDR WL. Ce dernier, basé sur une décomposition orthogonale originale du signal utile introduisant une contrainte supplémentaire, prend en considération la non circularité du signal utile et celle des interférences. L'étude des performances de ce beamformer a montré que ce dernier améliore toujours les performances en présence de signaux non circulaires. Dans le même contexte et pour la réception de signaux non gaussiens, nous avons introduit et étudié un beamformer MVDR non linéaire de Volterra. Ce beamformer dont les contraintes s'adaptent à la non circularité des brouilleurs, a été étudié à l'ordre trois sous sa forme équivalente GSC. Cette structure, dite complète, prend en compte conjointement des propriétés de non circularité et de non gaussianité des brouilleurs. L'analyse des performances en gains en SINR de ce récepteur est donnée pour la réception d'un signal réel corrompu par des brouilleurs non gaussiens et non circulaires d'ordre deux et quatre. Cette analyse a montré que la prise en considération de ces propriétés améliore toujours les performances. Dans une deuxième partie nous nous intéressons au contexte de détection selon deux volets: Le premier volet consiste en la détection d'un signal utile réel connu de paramètres inconnus, noyé dans un bruit total potentiellement non circulaire au SO et de matrice de covariance inconnue. Ainsi, suivant une approche basée sur le test de rapport de vraisemblance généralisé GLRT (Generalized Likelihood Ratio Test), de nouveaux récepteurs pour la détection d'un signal réel connu avec différents ensembles de paramètres inconnus ont été récemment introduits. Néanmoins, les performances de ces récepteurs, n'ont été que partiellement étudiées. Notre contribution a porté sur l'étude des distributions exactes et asymptotiques des statistiques associées au LRT et au GLRT sous H_0 et H_1. Cette étude a permis de donner les expressions théoriques exactes des probabilités de détection et de fausse alarme des récepteurs LRT, et celles asymptotiques pour certains récepteurs GLRT. Nous avons aussi complété cette analyse par des simulations Monte-Carlo en courbes ROC (Receiver Operating Characterisics) pour l'ensemble des détecteurs GLRT. Le deuxième volet, consiste en la détection de non circularité au SO de signaux aléatoires mono et multidimensionnels complexes. Nous avons donné la distribution asymptotique du GLR de non circularité sous H_0 et H_1 dérivé sous l'hypothèse de distribution gaussienne mais utilisée sous une distribution arbitraire non nécessairement gaussienne des données. Ces données considérées sont indépendantes, mais non nécessairement identiquement distribuées, ce qui permet de traiter des situations pratiques où les données non circulaires sont perturbées par un résidu de fréquence et un bruit additif gaussien circulaire. Cette analyse a été aussi complétée par des courbes ROC. / This thesis is devoted to the study of exploiting the properties of non-circularity and non-Gaussianity of signals in array processing. In the first part of this thesis, we focus on beamforming technics in the context of the reception of an unknown signal, whose steering vector is known, corrupted by potentially non-circular and/or non-Gaussian noise. In recent studies, a widely linear minimum variance distortionless response beamformer (WL MVDR) exploiting the second order (SO) non-circularity of interference was introduced and analyzed. However, this beamformer remains suboptimal for the reception of a non-circular useful signal, since it does not exploit the non-circularity of this latter. Thus, our contribution has focused on the introduction, the performances analysis and the implementation of a WL MVDR Beamformer. This latter, based on an original orthogonal decomposition of the useful signal, take into account the SO non-circularity of both useful signal and interferences. The new performances analysis of this new beamformer has shown that it always improves the performance of the well known Capon beamformer and the WL MVDR beamformer introduced recently, this in the presence of non-circular signals. In the same context and for receiving non-Gaussian signals, we introduced and studied a nonlinear MVDR Beamformer based on comlexe Volterra filters. This Beamformer, which adapt the constraints to the non circularity of jammers, has been studied in the third order by its equivalent GSC form. The performance analysis of this beamformer are shown in term of SINR Gains for the recepetion of non-Gaussian and SO (until to fourth order) non-circular. It is shown that taking into account of these properties always improves performance. In the second part, we focus on two parts of detection: The first part consists of the detection a known signal, with unknown parameters, corrupted by a total noise potentially SO noncircular with unknown covariance matrix. Thus, following Generalized Likelihood Ratio Test approach, new receivers for the detection a real known signal with different sets of unknown parameters have been recently introduced. Nevertheless, the performances analysis of these receptors have only been partially studied. Our contribution has focused on the study of exact and asymptotic distributions of statistics associated with the LRT and GLRT under H$_0$ and H$_1$. This study has given theoretical expressions of probabilities of correct detection and false alarm. We also supplemented this analysis with Monte Carlo simulations and given receiver operating characterisics ROC curves. In the second part, we consider the problem of testing impropriety (i.e., second-order noncircularity) of a complex valued random variable based on the generalized likelihood ratio test (GLRT) for Gaussian distributions. Asymptotic (w.r.t. the data length) distributions of the GLR are given under the hypothesis that data are proper or improper, and under the true, not necessarily Gaussian distribution of the data. The considered data are independent but not necessarily identically distributed: assumption which has never been considered until now. This enables us to deal with the practical important situations of noncircular data disturbed by residual frequency offsets and additive circular noise. The receiver operating characteristic (ROC) of this test is derived as byproduct, an issue previously overlooked. Finally illustrative examples are presented in order to strengthen the obtained theoretical results.

I visualized the flash-boiling atomization of liquid jets released into a low pressure environment at frame rates of up to five million frames per second. Such a high temporal resolution allowed us to observe for the first time the bubble expansion mechanism that atomizes the jet. To visualize the dynamics in detail, I focused closely to the outflow of the nozzle using a long distance microscope objective. I documented an abrupt transition from a laminar to a fully external flashing jet by systematically reducing the ambient pressure. I performed experiments with different volatile liquids and using nozzles with different inner diameters. The inner diameters of the nozzles varied from 30 to 480 µm. Perfluorohexane (PFnH) was our main working fluid, but also methanol, ethanol and 1-bromopropane were tested. Surprisingly, minimum intensity profiles revealed spray angles close to θs ~360°, meaning drops are ejected in all directions. Also, I measured speeds of bubble expansion up to 140 m/s. That is 45 times faster than the upper bound for inertial growth speed in complete vacuum from the Rayleigh-Plesset equation. I also calculated the trajectories of the ejected droplets as well as the drop speed distribution using particle tracking. I expect that our results bring new insight into the flash-boiling atomization mechanism.

Indiana University-Purdue University Indianapolis (IUPUI) / This thesis is a comprehensive investigation into the mechanics of evaporation experienced by planetesimals during accretion, a planet-building process. The evaporation events that these rocky bodies experience govern their chemical evolution, impacting the chemistry of the final body – a planet. Studying these planet-building processes is notoriously difficult (e.g., Sossi et al., 2019). There are still many unknowns surrounding what controls the degree of evaporation these bodies experience, and the resulting chemical signatures. The current study was designed to attempt to define some important parameters that govern silicate melt evaporation. Here, we isolate and evaluate the effects of (1) pressure, (2) oxygen fugacity and (3) the activity coefficient of MgO on evaporating planetesimals through a series of computational models. The model introduced in this study, the ƒO2 Modified KNFCMAS Model, uses a robust stepwise routine for calculating evaporative fluxes from a shrinking sphere. The modelling results are then compared to data from partial evaporation experiments of synthetic chondrite spheres to demonstrate the validity of this model, and to expose unknowns about the physicochemical conditions of high temperature silicate melts experiencing evaporation (in this case, the effective pressure, and the activity coefficient of MgO). Major element-oxide and isotope data from the models yielded two main conclusions concerning planetesimals: (1) the rate of evaporation is controlled by pressure and oxygen fugacity and (2) the chemical composition of the residual melt is controlled by oxygen fugacity and the activity coefficient of MgO. Results from computational modelling and evaporation experiments were used to determine an approximation for the activity coefficient of MgO in a simplified chondritic composition, as well as the effective pressure experienced by the evaporating spheres during the partial evaporation experiments. This study outlines the controls on planetesimal chemistry during evaporation and provides a more accessible means of studying these complex processes.