Sand dynamics along the Belgian coast based on airborne hyperspectral data and lidar data

The goal of this project was to explore the possibilities of airborne hyperspectral data and airborne lidar data to study sand dynamics on the Belgian backshore and foreshore. The Belgian coast is formed by a sandy strip at the southern edge of the North Sea Basin which is commonly known as the Southern Bight. Since the beach is prone to structural and occasional erosion, it is very important to obtain a better understanding of the processes controlling it. The combination of multi-temporal hyperspectral data and lidar data provides a suitable tool for follow-up of the Belgian coastline, and sandy coastlines in general. Hyperspectral imagery generates a reflectance spectrum for each pixel in the image. The shape of this spectrum is influenced by the composition of the topsoil of the beach, being mainly the mineralogical composition and the grain size. A Spectral Angle Mapper (SAM) algorithm was used to perform a supervised classification of the hyperspectral images in order to distinguish between different sand types. Digital terrain models (DTM’s) with a mean vertical accuracy of 5 cm were generated from lidar data. By differencing a DTM from September 2000 and one from September 2001 a map with sedimentation and erosion zones was generated. By combining the erosion/sedimentation map with the classified hyperspectral images, dating from August 2000 and August 2001, an appropriate and cost-effective method was found for studying the processes of sand transport along the Belgian coastline

Nucleation and phase selection in undercooled melts: Magnetic alloys of industrial relevance (MAGNEPHAS)

Studies of phase selection and microstructure evolution in high-performance magnetic materials are an urgent need for optimization of production routes. Containerless solidification experiments by electromagnetic levitation and drop tube solidification were conducted in undercooled melts of Fe-Co, Fe-Ni soft magnetic, and Nd-Fe-B hard magnetic alloys. Melt undercooling under microgravity was achieved in the TEMPUS facility during parabolic flight campaigns. For Fe-Co and Fe-Ni alloys significant effects of microgravity on metastable phase formation were discovered. Microstructure modifications as well as metastable phase formation as function of undercooling and melt flow were elucidated in Nd-Fe-B. Modeling of solidification processes, fluid flow and heat transfer provide predictive tools for microstructure engineering from the melt. They were developed as a link between undercooling experiments under terrestrial and microgravity conditions and the production routes of magnetic materials

Heat Treated NiP–SiC Composite Coatings: Elaboration and Tribocorrosion Behaviour in NaCl Solution

Tribocorrosion behaviour of heat-treated NiP and NiP–SiC composite coatings was investigated in a 0.6 M NaCl solution. The tribocorrosion tests were performed in a linear sliding tribometer with an electrochemical cell interface. It was analyzed the influence of SiC particles dispersion in the NiP matrix on current density developed, on coefficient of friction and on wear volume loss. The results showed that NiP–SiC composite coatings had a lower wear volume loss compared to NiP coatings. However, the incorporation of SiC particles into the metallic matrix affects the current density developed by the system during the tribocorrosion test. It was verified that not only the volume of co-deposited particles (SiC vol.%) but also the number of SiC particles per coating area unit (and consequently the SiC particles size) have made influence on the tribocorrosion behaviour of NiP–SiC composite coatings

PEGASUS: Design of a Stratospheric Long Endurance UAV System for Remote Sensing

project’s aim is to provide an economic way to gather high resolution data (visual, IR and thermal imagery, LIDAR, SAR, atmospheric measurements) from a high altitude platform. Because the platform will not be manned, it will be able to operate continuously for weeks or months. The paper describes the various aspects involved in the design of both platform and instruments. These include optical design, weight considerations, power consumption, data transmission, processing and archiving. The design is driven by the requirements of many remote sensing applications. RÉSUMÉ: Le projet PEGASUS (Policy support for European Governments by Acquisition of information from Satellite and UAV borne Sensors) a pour but de fournir des images à très haute résolution spatiale au moyen de capteurs aéroportés (visible, infrarouge, thermique, LIDAR, SAR et mesures atmosphériques) placés sur une plateforme opérant à très haute altitude. De par le caractère inhabité de la plateforme, celle-ci pourra acquérir les données requises de façon continue durant des semaines, voir des mois. Ce document décrit les différents aspects concernant les concepts tant de la plateforme porteuse que des instruments se trouvant à son bord. Sont décrit ci-dessous l’optique nécessaire, les considérations liées au poids et à la puissance électrique des divers instruments, les besoins en matière de transmission des données, de leur traitement ainsi que de leur archivage. Toutes ces considérations sont fondées sur les besoins réels rencontrés par de nombreuses applications de télédétection. 1

The electrolytic codeposition of silica and titania modified silica with zinc

This paper describes the electrolytic codeposition of pure and titania modified spherical silica particles with zinc from zinc sulfate electrolytes on a rotating disk electrode. The adsorption of zinc ions onto silica and the morphology of composite zinc-silica coatings as a function of the pH of the plating solution were investigated. It was found that the adsorption of zinc ions onto silica, the codeposition of silica, and the formation of hydroxides increase with pH. Titania modified silica particles were found to codeposit at low pH. Their incorporation In zinc from low pH electrolytes is explained based on an electrode blocking effect by the adsorbed particles leading to a local pH increase in the vicinity of the cathode. This leads to the formation of zinc hydroxides which causes silica particles to be codeposited with zinc even from plating solutions of low bulk pH.status: publishe