FUSION D'IMAGES TOMODENSITOMETRIQUES ET TOMOSCINTIGRAPHIQUES DANS LE NEUROBLASTOME DE L'ENFANT

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Optimization of the cathodic protection system of military ships with respect to the double constraint: cathodic protection and electromagnetic silencing

International audienceIn ships, materials of different electrochemical potentials - the steel of the hull and the bronze of the propellers - coexist. Once bathed in the sea water and electrically connected by the internal structures, phenomena of corrosion induced by galvanic coupling appear. These phenomena create currents in the water around the ship and induce, in the conducting sea water, a static electric field called "Underwater Electric Potential Field (UEP)" and a static magnetic field associated called “Corrosion Related Magnetic Field (CRM)”, harmful to the electromagnetic silencing of the ship. In order to protect the hull and the other sensitive anodic parts of the ship against corrosion, cathodic protection systems are installed on the hull. This paper describes a response surface methodology to optimize the design of cathodic protection systems of military ships with respect to the double constraint: cathodic protection and electromagnetic silencing

Ships hull corrosion diagnosis from close measurements of electric potential in the water

International audienc

Corrosion Diagnosis of a Ship Mock-Up From Near Electric-Field Measurements

International audienceWe present here an original application linking an electrochemical phenomenon and the computational aspect of electromagnetic fields to provide a corrosion diagnosis of a protected underwater steel structure. This is done with the pairing of a boundary element method and the resolution of an inverse problem. After a defined operating time, it is mandatory to check an underwater steel structure. Sadly, current examinations techniques require immobilizing the structure for a long time and are less efficient. The purpose of this paper is to replace this checking by a series of close electrical measurements in the conducting water which provides a corrosion diagnosis of the structure. The new method introduced ensures great time-savings but also an accuracy never reached before. This paper presents this numerical method and its checking through real electrical measurements on a frigate mock-up

A Post-Processing Integral Formulation for the Computation of Magnetic Field in Conductors

International audienceWe present here an original method of computing the magnetic induction in a conductor thanks to a post-processing from the boundary elements method (BEM). The paper gives the main keys of the algorithm, from the theoretical aspect as well as the practical one. This general formulation is then applied to simulated cases and finally to a real underwater electric system under cathodic protection

A Post-processing Integral Formulation for the Computation of Magnetic Field in Conductors

International audienc

A Post-processing Integral Formulation for the Computation of Magnetic Field in Conductors

International audienc

Inversion improvement of a corrosion diagnosis thanks to an inequality constraint

International audienceThis article presents a direct application of a Tikhonov inversion with a quadratic constraint applied in the case of a corrosion diagnosis. The main originality of this method is to inject physical information during the inversion to automatically restrict the Tikhonov parameter space. This application is then tested on a real case of corrosion diagnosis from electrical measurements in the water

Ships Hull Corrosion Diagnosis From Close Measurements of Electric Potential in the Water

International audienceWe present here an original method to search the corroded zones of an underwater steel structure. Nowadays, after a defined navigation period, a vessel is placed in dry dock, to examine its hull state, find the damaged areas and then paint them. This step of identification, very long and relatively inefficient, could be replaced by a series of electrical measurements which would be processed to get clues about the state of the hull. Those results are obtained thanks to the study of the cathodic protection system equipped on the hull. This new method allows a great timesaving but also a precision never reached before

Diagnostic de corrosion de structures métalliques sous-marines sous protection cathodique. Utilisation de méthodes inverses à partir de mesures électriques

International audienc