Föreliggande studie har en kvalitativ ansats där syftet är att genom intervjuer lyfta fram och tolka hur förskollärare själva uppfattar sitt arbete med matematik och därigenom få en djupare förståelse för matematik i förskolan samt bidra med kunskap om hur användandet av den sker i förskolan. Studiens syfte har framkommit då forskning återkommande belyser att barns tidiga matematiska kunskaper försämras allt mer och att Sverige är ett av de nordiska länderna med lägst genomsnitt i matematikkunskaper. Studien utgår från ett hermeneutiskt perspektiv där de centrala begreppen tolkning, hermeneutisk spiral, förståelse samt förförståelse använts som analysverktyg. Intervjuerna baserades på öppna frågor som genomfördes med sex förskollärare från olika avdelningar och verksamheter. I studiens resultat synliggörs det utifrån respondenternas uttalande att matematik är ett viktigt ämne att arbeta med redan i förskolan och att det kan förekomma olika strategier för att implementera det i verksamheten. Men å andra sidan belyser studien att det enligt förskollärarnas uttalande kan förekomma hinder som de anser vara problematiska för att aktivt kunna arbeta med matematik som ett ämne i förskolan.

Made available in DSpace on 2017-07-10T17:37:46Z (GMT). No. of bitstreams: 1 Roberto_Aparecido_Corredato.pdf: 1351778 bytes, checksum: 24481a0929511871cf9e821159a11e1b (MD5) Previous issue date: 2011-08-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work had as objective the productive and economic analysis of clones of seringueira (Hevea brasiliensis) submitted the different frequency of bleeding. The experiment was installed in the City of Indianópolis - PR. For accomplishment of the study it was used four clones of seringueira in production the 12 years, in espaçamento of 8,0m x 4,0m. Clones studied had been PB235, IAN873, GT1 and RRIM600, and the treatments had constituted of systems of bleeding in form of half spiral with frequency of bleeding to each three days, each four days and each five days, with ten repetitions (trees), for a period of three months/harvest. The collection of the data occurred at two times, 2009/2010 harvest and harvest 2010/2011, becoming fullfilled six evaluations, with the register of the latex productivity (g tree-1 month-1) coagulado of course in the earthen bowls of harvest. For accomplishment of the economic analysis the used data had been the gotten ones and practising in the area of the present work. Clones studied PB 235, IAN 873, GT1 and RRIM 600 had not presented increase in the latex productivity with the increase of the bleeding frequency. Clone PB235, in reduced frequency presented a net revenue 40% greater that clone IAN873, 30% greater that clone GT1 and 15% greater that clone RRIM600. Clone RRIM600 in reduced frequency presented a net revenue 30% greater that clone IAN873 and 18% greater that clone GT1. Clone GT1 in reduced frequency presented a net revenue 14% greater that clone IAN873. Clone IAN873 in reduced frequency presented the lesser net revenue. The annual net revenue in the present work is bigger in reduced frequency for clone PB235, followed for clones RRIM600, GT1 and clone IAN873 / Este trabalho teve como objetivo a análise produtiva e econômica de clones de seringueira (Hevea brasiliensis) submetidos a diferentes frequências de sangria. O experimento foi instalado no Município de Indianópolis - PR. Para realização do estudo foi utilizado quatro clones de seringueira em produção a 12 anos, em espaçamento de 8,0m x 4,0m. Os clones estudados foram PB235, IAN873, GT1 e RRIM600, e os tratamentos constituíram de sistemas de sangria em forma de meia espiral com frequência de sangria a cada três dias, a cada quatro dias e a cada cinco dias, com dez repetições (árvores), por um período de três meses/safra. A coleta dos dados ocorreu em duas épocas, safra 2009/2010 e safra 2010/2011, realizando-se seis avaliações, com o registro da produtividade de látex (g árvore-1 mês-1) coagulado naturalmente nas tigelas de colheita. Para realização da análise econômica os dados utilizados foram os obtidos e praticados na área do presente trabalho. Os clones estudados PB 235, IAN 873, GT1 e RRIM 600 não apresentaram aumento na produtividade de látex com o aumento da frequência de sangria. O clone PB235, em frequência reduzida apresentou uma receita líquida 40% maior que o clone IAN873, 30% maior que o clone GT1 e 15% maior que o clone RRIM600. O clone RRIM600 em frequência reduzida apresentou uma receita líquida 30% maior que o clone IAN873 e 18% maior que o clone GT1. O clone GT1 em frequência reduzida apresentou uma receita líquida 14% maior que o clone IAN873. O clone IAN873 em frequência reduzida apresentou a menor receita líquida. A receita líquida anual no presente trabalho é maior em frequência reduzida para o clone PB235, seguido pelos clones RRIM600, GT1 e o clone IAN873

Hollow fibre and spiral wound membrane (SWM) modules are the most common commercially available membrane modules. The latter dominate especially for RO, NF and UF and are the focus of this study. The main difficulty these types of modules face is concentration polarisation. In SWM modules, the spacer meshes that keep the membrane leaves apart also help reduce the effects of concentration polarisation. The spacer filaments act as flow obstructions, and thus encourage flow destabilisation and increase mass transfer enhancement. One of the detrimental aspects of the use of spacers is an increase of pressure losses in SWM modules. This study analyses the mechanisms that give rise to mass transfer enhancement in narrow spacer-filled channels, and investigates the relationship between flow destabilisation, energy losses and mass transfer. It shows that the regions of high mass transfer on the membrane surface correlate mainly with those regions where the fluid flow is towards the membrane. Based on the insights gained from this analysis, a series of multi-layer spacer designs are proposed and evaluated. In this thesis, a Computational Fluid Dynamics (CFD) model was used to simulate steady and unsteady flows with mass transfer in two- and three-dimensional narrow channels containing spacers. A solute with a Schmidt number of 600 dissolving from the wall and channel Reynolds numbers up to 1683 were considered. A fully-developed concentration profile boundary condition was utilised in order to reduce the computational costs of the simulations. Time averaging and Fourier analysis were performed to gain insight into the dynamics of the different flow regimes encountered, ranging from steady flow to vortex shedding behind the spacer filaments. The relationships between 3D flow effects, vortical flow, pressure drop and mass transfer enhancement were explored. Greater mass transfer enhancement was found for the 3D geometries modelled, when compared with 2D geometries, due to wall shear perpendicular to the bulk flow and streamwise vortices. Form drag was identified as the main component of energy loss for the flow conditions analysed. Implications for the design of improved spacer meshes, such as extra layers of spacer filaments to direct the bulk flow towards the membrane walls, and filament profiles to reduce form drag are discussed.

Le projet SPIRAL2, en phase de construction au GANIL à Caen, viendra augmenter les capacités de production et d'accélération de l'actuelle installation SPIRAL. Cette extension consiste en la construction d'une zone de production d'isotopes radioactifs associée à un accélérateur linéaire supraconducteur. Ce dernier permet l'accélération de faisceaux de deutons de 5 mA à 40 MeV ainsi que d'une grande variété d'ions (protons, deutons, ions ayant un rapport charge/masse de 1/3) jusqu'à une énergie de 14.5 MeV/u et un courant de 1 mA. Le taux de fission visé (~ 1014 fissions/s) ainsi que cette grande polyvalence d'accélération sont rendus possible grâce à l'utilisation de la technologie supraconductrice. L'étude, la conception et l'intégration des modules accélérateurs supraconducteurs de la partie haute énergie ont été effectuées à l'Institut de Physique Nucléaire d'Orsay (IPNO). Le travail de thèse présenté ici s'inscrit dans ce contexte. Dans un premier temps, les cavités accélératrices supraconductrices de type quart-d'onde ont été validées et caractérisées d'un point de vue électromagnétique et mécanique en cryostat de qualification (-269 °C). Par la suite, un module accélérateur totalement équipé a été qualifié en configuration dite « machine ». Des études plus spécifiques ont également été menées sur l'effet 100K, les microphonies et la caractérisation du système d'accord en fréquence par plongeur mobile, système novateur pour les cavités supraconductrices. La validation des performances du module accélérateur à travers ce travail de thèse a donné lieu au lancement de la phase de fabrication des cavités accélératrices et des cryomodules.

L'existence éventuelle de multineutrons liés, suggérée par de récents résultats expérimentaux serait susceptible de remettre radicalement en cause bien des certitudes établies sur l'interaction nucléon-nucléon. Nous avons choisi d'utiliser la réaction 8He(d,6Li) pour mesurer le spectre d'énergie du système 4n afin d'y rechercher la présence d'un pic signant l'existence éventuelle d'un noyau lié neutre : le « Tetraneutron », ou bien celle d'un état résonant à basse énergie d'excitation. Cette étude a été menée au GANIL en utilisant le faisceau secondaire de 8He de 15.8 A.MeV fourni par SPIRAL. L'ensemble de détecteurs Silicium à pistes MUST a été utilisé pour mesurer les angles d'émission et les énergies des 6Li, et en déduire la masse manquante du système des quatre neutrons. Une nouvelle expérience réalisée en 2004 avec une statistique plus élevée et une meilleure détermination du fond n'a pas permis de confirmer l'existence de la structure étroite observée en 2002 à une énergie d'environ 2.5 MeV .L'analyse des résultats démontre cependant la présence de fortes corrélations entre les quatre neutrons émis.

Ce travail de thèse est dédié à l'étude des noyaux lourds soumis à des conditions extrêmes de spin et d'isospin. Les expériences présentées ont été menées à l'IReS de Strasbourg et au GANIL de Caen avec les multidétecteurs gamma EUROBALL IV et EXOGAM auprès, respectivement, des accélérateurs VIVITRON et SPIRAL. Les noyaux étudiés ont été peuplés via des réactions de fusion-évaporation. Pour exploiter les données, nous avons développé de nouvelles méthodes d'analyse reposant sur la logique floue. <br> Deux expériences ont été réalisées auprès d'EUROBALL IV et portaient sur les noyaux superdéformés de masse A~190-200 à savoir les isotopes superdéformés de plomb 197,l98Pb et l'isotope superdéformé de bismuth 196Bi. Dans le premier cas, nous avons découvert six nouvelles bandes superdéformées ce qui nous a permis de mettre en évidence un couplage entre vibrations octupolaires et excitations intrinsèques. Dans le second, nous avons observé la transition superdéformée gamma de plus basse énergie si on exclut les isomères de fission. Ces résultats ont été interprétés à partir de calculs théoriques microscopiques auto-cohérents statiques et dynamiques effectués en collaboration avec des physiciens des groupes de Physique Théorique de l'IPN Lyon et du SPTh/Saclay. <br> La dernière partie de ce travail a concerné la recherche de grandes déformations dans les noyaux de terres-rares de la zone de masse A~120-130 très déficients en neutrons situés près de la ligne d'émission spontanée de proton. Cette étude a été mise en oeuvre avec le multidétecteur gamma EXOGAM en couplage avec le détecteur de particules chargées légères DIAMANT et le faisceau radioactif de 76Kr délivré par SPIRAL.

Although a tropical cyclone may conceptually be regarded as an axisymmetric vortex, there is substantial evidence that asymmetric dynamics play an important role. In this thesis, dynamical impacts of rotating convective asymmetries are examined in this thesis. Two types of rotating convective asymmetries are considered: rotating eyewall convective maximum which is located in the core region of the storm and spiral bands which are located outside the core. Both of them can be characterized as rotating asymmetric convective heat sources, and they are superimposed on a balanced, axisymmetric vortex to approximate the effect of rotating eyewall convective maximum and spiral bands on tropical cyclone by using a simple nonhydrostatic three-dimensional, but linear model that is based on vortex anelastic equations. The evolution of rotating convective asymmetric heat sources on a balanced, axisymmetric vortex, which is modeled after tropical cyclones, is investigated to examine angular momentum transport by gravity waves that radiate away from the core region. Results show that gravity waves can transport angular momentum away from a tropical cyclone, but a very small amount, which is several orders of magnitude smaller than the estimate by recent studies. The significantly large difference may largely be due to the difference between two-dimensional and three-dimensional adjustment processes. Assuming that the effects of spiral bands on tropical cyclone wind field are caused by the response to diabatic heating in their convection, rotating asymmetric heat sources are constructed to reflect observations of spiral bands. These heat sources are rotated around a realistic but idealized balanced axisymmetric vortex. Simulation results show that the response of tropical cyclone wind field to idealized spiral band heat sources can successfully capture a number of observed well-known features of spiral band circulation, such as overturning secondary circulation, descending mid-level inflow, and cyclonic tangential acceleration. Comparison to full-physics numerical simulations confirms the validity of this method which provides a simple dynamical framework to better understand the impact of spiral bands in tropical cyclone.

Origin and symmetry of the observed global magnetic fields in galaxies are not fully understood. We intend to clarify the question of the magnetic field origin and investigate the global action of the magneto-rotational instability (MRI) in galactic disks with the help of 3D global magneto-hydrodynamical (MHD) simulations. The calculations were done with the time-stepping ZEUS 3D code using massive parallelization. The alpha-Omega dynamo is known to be one of the most efficient mechanisms to reproduce the observed global galactic fields. The presence of strong turbulence is a pre-requisite for the alpha-Omega dynamo generation of the regular magnetic fields. The observed magnitude and spatial distribution of turbulence in galaxies present unsolved problems to theoreticians. The MRI is known to be a fast and powerful mechanism to generate MHD turbulence and to amplify magnetic fields. <br><br> We find that the critical wavelength increases with the increasing of magnetic fields during the simulation, transporting the energy from critical to larger scales. The final structure, if not disrupted by supernovae explosions, is the structure of `thin layers' of thickness of about 100 pcs. An important outcome of all simulations is the magnitude of the horizontal components of the Reynolds and Maxwell stresses. The result is that the MRI-driven turbulence is magnetic-dominated: its magnetic energy exceeds the kinetic energy by a factor of 4. The Reynolds stress is small and less than 1% of the Maxwell stress. <br><br> The angular momentum transport is thus completely dominated by the magnetic field fluctuations. The volume-averaged pitch angle is always negative with a magnitude of about -30. The non-saturated MRI regime is lasting sufficiently long to fill the time between the galactic encounters, independently of strength and geometry of the initial field. Therefore, we may claim the observed pitch angles can be due to MRI action in the gaseous galactic disks. The MRI is also shown to be a very fast instability with e-folding time proportional to the time of one rotation. Steep rotation curves imply a stronger growth for the magnetic energy due to MRI. The global e-folding time is from 44 Myr to 100 Myr depending on the rotation profile. Therefore, MRI can explain the existence of rather large magnetic field in very young galaxies. We also have reproduced the observed rms values of velocities in the interstellar turbulence as it was observed in NGC 1058. We have shown with the simulations that the averaged velocity dispersion of about 5 km/s is a typical number for the MRI-driven turbulence in galaxies, which agrees with observations. The dispersion increases outside of the disk plane, whereas supernovae-driven turbulence is found to be concentrated within the disk. In our simulations the velocity dispersion increases a few times with the heights. <br><br> An additional support to the dynamo alpha-effect in the galaxies is the ability of the MRI to produce a mix of quadrupole and dipole symmetries from the purely vertical seed fields, so it also solves the seed-fields problem of the galactic dynamo theory. The interaction of magneto-rotational instability and random supernovae explosions remains an open question. It would be desirable to run the simulation with the supernovae explosions included. They would disrupt the calm ring structure produced by global MRI, may be even to the level when we can no longer blame MRI to be responsible for the turbulence. / Die Beobachtung polarisierter Synchrotronstrahlung mit modernen Radioteleskopen zeigen die Existenz von großskaligen Magnetfeldern in Galaxien. Mit den ständig verbesserten Beobachtungsinstrumenten findet man Magnetfelder in immer mehr Galaxien, so dass man annehmen kann, Magnetfelder treten mehr oder weniger in allen Galaxien auf. Selbst in sehr jungen Galaxien (damit weit entfernten) wurden schon Magnetfelder von einigen mikroG gefunden.<br> Eine mögliche Erklärung für die Entstehung der Magnetfeldern ist die Wirkung eines turbulenten Dynamos. Neben Supernova-Explosionen können magnetische Instabilitäten eine Quelle für die Turbulenz im interstellaren Medium sein. So werden Galaxien bei Anwesenheit eines schwachen Magnetfeldes auf Grund der &quot;Magneto-Rotations-Instabilität&quot; (MRI) turbulent. Die globale Entwicklung des interstellaren Gases in Galaxien unter Wirkung der MRI ist in der vorliegenden Arbeit betrachtet worden.<br> Mit drei-dimensionalen numerischen Simulationen auf großen Clusterrechnern wurde die zeitliche Entwicklung des Geschwindigkeitsfeldes und der Magnetfelder untersucht. Für die extrem rechenintensiven globalen Modelle wurde ein hochgradig parallelisierbares Rechenprogramm zur Lösung der MHD-Gleichungen an die Problemstellung angepasst, in der Rechenzeit optimiert und ausführlich getestet. <br> Es konnte erstmalig die zeitliche Entwicklung des interstellaren Gases unter dem Einfluss eines schwachen Magnetfeldes über mehrere Milliarden Jahre verfolgt werden. In der galaktischen Scheibe entwickelt sich Turbulenz mit einer Geschwindigkeitsdispersion von einigen km/s und großskalige Magnetfelder von einigen mikroG, genau wie in realen Galaxien beobachtet. Damit konnte der Nachweis erbracht werden, dass das interstellare Gas durch Wirkung der MRI auch bei geringer Sternaktivität Turbulenz entwickelt, wie es in einigen ruhigen Galaxien auch beobachtet wird.<br> Ein anderes wichtiges Resultat ist die Entstehung großskaliger Magnetfelder aus kleinskaligen Strukturen in der Art eines turbulenten Dynamos. Die Wachstumsrate der magnetischen Energie geht bei diesem Prozess mit der Umlaufzeit, schnell genug um auch Magnetfelder mit einigen mikroG in sehr jungen Galaxien zu erreichen.<br> Die Entstehung von Magnetfeldern aus der MRI löst auch die bisher ungeklärte Frage nach der Geometrie der Saatfelder für turbulente Dynamos.

Cosmic reionization was most likely initiated by star forming dwarf galaxies. Little is known about the physical mechanisms allowing ionizing Lyman continuum (LyC) photons to escape from galaxies, but to learn more we can study local galaxies in detail. Until now, there has however only been one claim of a local LyC leaking galaxy, the disputed case of Haro 11. The lack of local detections could in part be a combined effect of technical problems and search strategies. Re-examining the FUSE (Far Ultraviolet Spectroscopic Explorer) data of Haro 11 led us to develop a new model for the spectral reduction, by which we could confirm an escape fraction of LyC photons (fesc) of 3.3±0.7%. In addition, eight more galaxies from the FUSE archive were examined leading to a new detection, Tol 1247-232, with fesc = 2.4±0.5%. The low value derived from the stacked spectrum of the whole sample, fesc = 1.4±0.4%, could be an indication of an evolving fesc scenario and/or an effect of probing the wrong targets. Local LyC candidates are normally selected among starburst galaxies with high equivalent widths in Hα. This can however give preference to ionization bounded H II regions with low escape fractions. In an attempt to overcome this selection bias, we developed a novel method to select LyC leaking galaxies. The selection is based on a blue continuum and weak emission lines, properties that in combination can be explained only by models with very high fesc. Using these criteria, we selected a sample of leaking candidates at z≈0.03 to be observed in Hα and Johnson B filters. The sample galaxies have properties that strongly favour leakage. Among these are clear signs of mergers and interaction with neighbouring galaxies, off-centre major star forming regions and spectral properties indicating previous starburst activity. The Lyman-alpha (Lyα) line is often used as a tracer for the distant galaxies believed to have reionized the universe. Here, for the first time local face-on spiral galaxies are studied in Lyα imaging. All three galaxies are emitting Lyα photons in the polar direction far out in the spiral arms, in clear contrast to previously studied irregular galaxies where strong emission is seen from the nuclei. If the small sample studied here is representative, it will have implications for detecting Lyα galaxies at high redshifts as it would depend strongly on the viewing angle.

The news media serve as the Canadian public’s main source of information about the Israeli-Palestinian conflict. This thesis examines the ways in which the Canadian media portray the conflict, through a lens of Habermas’ (1962) public sphere theory, Foucault’s (1926 – 1984) ideas on discourse, and Rawls’ (1921 – 2002) conceptions of equality and justice. Building on these theories, Noelle-Neumann’s Spiral of Silence theory (1974), Said’s Orientalism (1978), and d’Arcy’s (1913 – 1983) conception of the right to communicate are examined to arrive at a framework for analyzing Canadian news. Looking at ideological representations, power manifestations, issue framing, and social responsibility within the media, this thesis explores whether the Canadian media portray the conflict in such a way that fosters a downward spiral of opinions within the Canadian public. A Critical Discourse Analysis of coverage in two national English Canadian newspapers, The Globe and Mail and the National Post, during three separate timeframes of increased violence in Israel and Palestine between 2000 and 2009 reveals that newspaper representations of the Israeli-Palestinian conflict are often entrenched in predefined ways of portraying the Other, fostering an Israeli-Palestinian spiral of silence in Canadian media.