Psychologie analytique | EPFL Graph Search

thumb|upright=1.5|Allégorie alchimique extraite de l'Alchimie de Nicolas Flamel, par le Chevalier Denys Molinier () et représentant les énergies conscientes et inconscientes se combinant pour guérir la personnalité.|alt=Allégorie alchimique (extraite de l'ouvrage Alchimie de Nicolas Flamel, par le Chevalier Denys Molinier ) représentant le caducée : bâton rouge surmonté d'un casque muni d'ailes (celui du dieu Hermès, patron des guérisseurs) et autour duquel s'enroulent deux serpents qui finissent par former une seule et même figure. En arrière-plan se détache un paysage bucolique. La psychologie analytique (Analytische Psychologie en allemand), ou « psychanalyse jungienne », est une théorie psychologique élaborée par le psychiatre suisse Carl Gustav Jung à partir de 1913. Créée au départ pour se différencier de la psychanalyse de Sigmund Freud, elle se propose de faire l'investigation de l'inconscient et de l'« âme », c'est-à-dire de la psyché individuelle. L'histoire de la psycholo

Longitudinal intensity effects in the CERN Large Hadron Collider

Juan Federico Esteban Müller

This PhD thesis provides an improved knowledge of the LHC longitudinal impedance model and a better understanding of the longitudinal intensity effects. These effects can limit the LHC performance and lead to a reduction of the integrated luminosity. The LHC longitudinal impedance was measured with beams. Results obtained using traditional techniques are consistent with the expectations based on the impedance model, although the measurement precision was proven insufficient for the low impedance of the LHC. Innovative methods to probe the LHC reactive impedance were successfully used. One of the methods is based on exciting the beam with a sinusoidal rf phase modulation to estimate the synchrotron frequency shift from potential-well distortion. In the second method, the impedance is estimated from the loss of Landau damping threshold, which is also found to be in good agreement with analytical estimations. Beam-based impedance measurements agree well with estimations using the LHC impedance model. Macroparticle simulations of loss of Landau damping reproduce the measurements precisely and are used to determine the current stability limits. The single-bunch stability is analyzed for the HL-LHC, for a bunch intensity almost twice higher than the nominal LHC intensity. The effect of an additional rf system installed for double rf operation provides an increased stability margin in the absence of a wideband longitudinal damper system. The differences between the bunch-shortening and bunch-lengthening operation modes are presented, as well as the effect of an error in the phase synchronization between both rf systems. Several options for the rf parameters are considered, and their advantages and drawbacks under different circumstances are analyzed. A novel diagnostic tool for e-cloud monitoring based on bunch phase measurements has been fully developed. An advanced post-processing was implemented to improve the measurement accuracy up to the required level by reducing systematic and random errors. The tool is available at the CERN Control Room and shows the e-cloud build-up structure along the bunch trains and the total beam power loss due to e-cloud. Phase shift measurements are in good agreement with simulations of the e-cloud buildup and can be used to estimate the heat load in the cryogenic system. The use of this method in operation has been proven to ease the scrubbing run optimization and can eventually be used as an additional input for the cryogenic system.

EPFL2016

Characterization of Wind Turbine Wakes with Nacelle-Mounted Doppler LiDARs and Model Validation in the Presence of Wind Veer

Peter Andreas Brugger, Fernando Carbajo Fuertes, Corey Dean Markfort, Fernando Porté Agel, Mohsen Vahidzadeh

Accurate prediction of wind turbine wakes is important for more efficient design and operation of wind parks. Volumetric wake measurements of nacelle-mounted Doppler lidars are used to characterize the wake of a full-scale wind turbine and to validate an analytical wake model that incorporates the effect of wind veer. Both, measurements and model prediction, show an elliptical and tilted spanwise cross-section of the wake in the presence of wind veer. The error between model and measurements is reduced compared to a model without the effect of wind veer. The characterization of the downwind velocity deficit development and wake growth is robust. The wake tilt angle can only be determined for elliptical wakes.

2019

Lidar measurements of yawed-wind-turbine wakes: characterization and validation of analytical models

Peter Andreas Brugger, Fernando Porté Agel, Haohua Zong

Wake measurements of a scanning Doppler lidar mounted on the nacelle of a full-scale wind turbine during a wake-steering experiment were used for the characterization of the wake flow, the evaluation of the wake-steering set-up, and the validation of analytical wake models. Inflow-scanning Doppler lidars, a meteorological mast, and the supervisory control and data acquisition (SCADA) system of the wind turbine complemented the set-up. Results from the wake-scanning Doppler lidar showed an increase in the wake deflection with the yaw angle and that the wake deflection was not in all cases beneficial for the power output of a downstream turbine due to a bias of the inflow wind direction perceived by the yawed wind turbine and the wake-steering design implemented. Both observations could be reproduced with an analytical model that was initialized with the inflow measurements. Error propagation from the inflow measurements that were used as model input and the power coefficient of a waked wind turbine contributed significantly to the model uncertainty. Lastly, the span-wise cross section of the wake was strongly affected by wind veer, masking the effects of the yawed wind turbine on the wake cross sections.

2020

Longitudinal intensity effects in the CERN Large Hadron Collider

Juan Federico Esteban Müller

EPFL2016