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A method to calculate the Stokes parameters Q, U, as well as angle of polarization (AoP) from the new generation CIMEL Dual-Polar sun/sky radiometer CE318-DP polarized skylight measurements is developed in this thesis. Besides the degree of linear polarization (DoLP) and the total radiance I, the parameters Q, U, and AoP have much potential to improve retrievals of aerosol microphysical and chemical properties. However, they have not been derived based on the CE318-DP so far because they change with the reference plane that is hard to know due to an uncontrolled initial angle related to installation of the optical sensor head to the automated mount of this type of instrument. In this work, the polarization pattern of skylight with the direction of polarization perpendicular to the scattering plane (i.e., the principal plane in the solar principal plane geometry) is applied to correct the initial angle and then to obtained Q, U, and AoP. The perpendicular and parallel polarized radiances Ir and Il, as well as the linear depolarization ratio ρ are further derived after Q is known. A new polarized almucantar geometry based on CE318-DP is measured to illustrate abundant variation features of these parameters. These new polarization parameters in conjunction with DoLP and I are analyzed based on some typical long-term sites within the Sun/sky-radiometer Observation NETwork (SONET) and a joint site of the AErosol RObotic NETwork (AERONET) in China. Results calculated in this work are consistent with previous results, and generally comparable with the vector radiative transfer simulations and the measurements by other polarimetric instrument. Considering a 1°discrepancy of AoP, 3% fractional uncertainty in I and 0.005 uncertainty in DoLP propagated to Q and U, the uncertainties of Q in both of solar principal and almucantar planes and that of U in the almucantar geometry are acceptable.

The composite structure of the nucleon leads to a spectrum of excited states, or resonances, which contain important constraints on the dynamics and interactions of its constituents. A major world programme measuring meson photoproduction from the nucleon is currently under way to improve our knowledge of this fundamental spectrum. These new generation of measurements exploit polarisation degrees of freedom of the incident photon along with spin degrees of freedom in the target and recoiling nucleons. The meson photoproduction process can be described by 16 independent experimental observables. To fully constrain the four underlying complex photoproduction amplitudes requires the measurement of a least 8 of these. Measurements of double polarisation observables, where the photon beam and nucleon target are polarised are crucial to achieve this requirement. This thesis will present the analysis and extraction of the first preliminary measurement of the double polarisation observable. F in the single pion photoproduction reaction γ→ + p →n + π+ was undertaken to measure both F and T. The resulting measurement of polarisation observables from this reaction in conjunction with with those from the Pπ0 channel will provide stringent constraints on partial wave analyses aiming to extract precision information on the properties of the low lying nucleon resonances.

Epithelzellen sind entlang einer apico-basolateralen Achse polarisiert. Die korrekte Insertion von Ionenkanälen und Transportproteinen ist für die normale Epithelfunktion unerlässlich. Im Gegensatz dazu sind migrierende Zellen in ihrer Bewegungsebene polarisiert, mit einem Lamellipodium und Zellkörper, die als Vorder- und Hinterende der Zell zu verstehen sind. In vorhergehenden Un- tersuchungen konnte gezeigt werden, dass Ionenkanäle und Transporter in be- stimmten Regionen von migrierenden Nierenepithelzellen (MDCK-F-Zellen) zu fin- den sind (z. B.: NHE1, Cl/HCO -Austauscher AE2). Diese reichern sich am Vor- derende der MDCK-F-Zellen an. Es war nicht bekannt, wo sich Markerproteine der apikalen Membran wiederfinden. Um dieser Frage nachzugehen, transfizierte ich MDCK-F-Zellen stabil mit dem Kalium-Kanal ROMK2. Dieser wird in der apikalen Membran im Nierensammelbecken expressioniert. Transfizierte Zellklone konnten durch Subcloning und RT-PCR-Experimente mit spezifischen ROMK2-Primern gefun- den werden. Desweiteren wurden Patch-Clamp-Experimente im Ganzzellmodus durch- geführt, um die Insertion von funktionellen ROMK2-Kanälen in die Zellmembran von transfizierten MDCK-F-Zellen nachzuweisen. Die mit dem Kalium-Kanal trans- fizierten Zellen produzieren einen Barium-hemmbaren Kalium-Strom, der in Mock- transfizierten Zellen nicht nachzuweisen war. Mock-transfizierte MDCK-F-Zellen migrieren mit einer Geschwindigkeit von ca 1,1 µm/min. Im Gegensatz dazu re- duziert die Insertion von ROMK2-Kanälen die Migrationsgeschwindigkeit auf 0,7 µm/min.In immunhistochemischen Experimenten konnte eine diffuse Verteilung des ROMK2 in MDCk-F-Zellen gezeigt werden. Diese Ergebnisse deuten darauf hin, daß es für 'apikale' und basolaterale' Proteine verschiedene intrazelluläre Transportwege in die Plasmamembran von migrierenden Zellen gibt. / Differentiated epithelial cells are polarized along an apico-basolateral axis and the insertion of ion channels and transporters into apical and basolateral membranes is a prerequisite for normal epithelial function. In contrast, migrating cells are polarized within the plane of movement with lamellipodium and cell body representing fromt and rear end of the cell. Previously, it was shown that ion channels and transporters are distributed unevenly in migrating renal epithelial MDCK-F cells. Proteins which are found in the basolateral membrane of differented epithelial cells (e. g. Cl/HCO exchanger AE2) are concentrated at the front of MDCK-F cells. It was unknown whether marker pro- teins of the apical membrane are also distributed unevenly in MDCK-F cells. To adress this question and gain more insight into the sorting mechanisms in mig- rating cells, I stably transfected the potassium channel ROMK2 into MDCK-F cells. ROMK2 is found in the apical membrane of the renal collecting duct. Transfected cell clones were identified by subcloning and sequencing RT-PCR products amplified with specific ROMK2 primers. I performed patch clamp ex- periments in the whole cell configuration in order to demonstrate the inser- tion of functional ROMK2 channels into the membrane of transfected MDCK-F cells. ROMK2 transfected MDCK-F cells express a Barium-sensitive potassium current which is absent in mock-transfected cells. While mock-transfected cells migrate at a rate of 1.1 µm/min ROMK2 channel expression reduces the rate of migration to 0.7 µm/min. The immunocytochemical analysis revealed a diffuse distribution of the ROMK2 protein in MDCK-F cells. These results pro- vide evidence that 'apical' and 'basolateral' proteins are delivered to the plasma membrane of migrating cells via distinct intracellular transport ways.

Les communautés de la physique nucléaire et des hautes énergies ont montré un intérêt croissant pour les faisceaux de positrons intenses et hautement polarisés. Des photons polarisés durs peuvent produire des positrons dans le champ atomique par création de paire, l'électron et le positron ainsi produits portent une partie de la polarisation de la particule initiale. Les récentes avancées dans le domaine des sources d'électrons à courants intenses (1 mA) et hautement polarisés au Jefferson Lab offrent la perspective de créer des positrons polarisés à partir d'électrons de faible énergie. Cette thèse se propose de discuter les transferts de polarisation aux positrons dans la perspective d'une optimisation du design d'une source de positron polarisée. L'expérience PEPPo, visant à mesurer la polarisation de positrons par un faisceau d'électrons de basse énergie (<10MeV) mais de basse intensité est discutée. Une démonstration concluante de cette technique fournirait une méthode alternative de produire des positrons polarisés de basse énergie et des informations utiles pour optimiser le design d'une source dans la gamme d'énergie inférieure au GeV. / The nuclear and high-energy physics communities have shown a growing interest in the availability of high current, highly-polarized positron beams. A sufficiently energetic polarized photon or lepton incident on a target may generate, via bremsstrahlung and pair creation within a solid target foil, electron-positron pairs that should carry some fraction of the initial polarization. Recent advances in high current (> 1 mA) spin polarized electron sources at Jefferson Lab offer the perspective of creating polarized positrons from a low energy electron beam. This thesis discusses polarization transfer from electrons to positrons in the perspective of the design optimization of a polarized positron source. The PEPPo experiment, aiming at a measurement of the positron polarization from a low energy (< 10 MeV) highly spin polarized electron beam is discussed. A successful demonstration of this technique would provide an alternative scheme for the production of low energy polarized positrons and useful information for the optimization of the design of polarized positron sources in the sub-GeV energy range.

This thesis presents a study of W±Z diboson production with the ATLAS experiment at the LHC. The measurements are made using 20.3fb⁻¹ of data collected during proton-proton collisions produced at a centre-of-mass energy of √s = 8 TeV. Final states with three leptons and missing transverse energy are considered. The first study of the polarisation of the W boson in such events is presented. This study provides a cross-section independent method by which to study anomalous gauge boson couplings. The estimated sensitivity of this measurement to anomalous gauge boson couplings will therefore also be presented. Also discussed, are measurements of the W±Z production cross-section and limits on anomalous gauge boson couplings. Finally, a study is presented which assess the impact of extending the inner-detector tracker to |η| = 4.0. This was considered for the ATLAS upgrade program. The effect of such an extension was studied for multiple final states, including the W±Z inclusive and VBS analyses as well as the WWW triboson analysis.

Reproduction de : Thèse de doctorat : Microonde, électromagnétisme et optoélectronique : Toulouse, INPT : 2008. / Texte en anglais. Titre provenant de l'écran-titre. Bibliogr. 146 réf.

Thèse doctorat : Mécanique et Energétique : Nancy 1 : 2007. / Titre provenant de l'écran-titre.

Thèse de doctorat : Physique de la matière condensée : Strasbourg : 2009. / Titre provenant de l'écran-titre. Notes bibliogr.

Thèse de doctorat : Géographie : Lille 1 : 2002 ; 3215 G. / Bibliogr. p. 448-461.