Mines ParisTech

About: Mines ParisTech is a education organization based out in Paris, France. It is known for research contribution in the topics: Finite element method & Microstructure. The organization has 6564 authors who have published 11676 publications receiving 359898 citations. The organization is also known as: École nationale supérieure des mines de Paris & École des mines de Paris.

Polymer-supported metals and metal oxide nanoparticles: synthesis, characterization, and applications

Abstract: Metal and metal oxide nanoparticles exhibit unique properties in regard to sorption behaviors, magnetic activity, chemical reduction, ligand sequestration among others. To this end, attempts are being continuously made to take advantage of them in multitude of applications including separation, catalysis, environmental remediation, sensing, biomedical applications and others. However, metal and metal oxide nanoparticles lack chemical stability and mechanical strength. They exhibit extremely high pressure drop or head loss in fixed-bed column operation and are not suitable for any flow-through systems. Also, nanoparticles tend to aggregate; this phenomenon reduces their high surface area to volume ratio and subsequently reduces effectiveness. By appropriately dispersing metal and metal oxide nanoparticles into synthetic and naturally occurring polymers, many of the shortcomings can be overcome without compromising the parent properties of the nanoparticles. Furthermore, the appropriate choice of the polymer host with specific functional groups may even lead to the enhancement of the properties of nanoparticles. The synthesis of hybrid materials involves two broad pathways: dispersing the nanoparticles (i) within pre-formed or commercially available polymers; and (ii) during the polymerization process. This review presents a broad coverage of nanoparticles and polymeric/biopolymeric host materials and the resulting properties of the hybrid composites. In addition, the review discusses the role of the Donnan membrane effect exerted by the host functionalized polymer in harnessing the desirable properties of metal and metal oxide nanoparticles for intended applications.

Image segmentation

Abstract: Firstly, the paper proposes an axiomatic definition for the notion of "segmentation" in image processing, which is based on the idea of a maximal partition. Then a key theorem links segmentation with connection, on the one hand, and with connective criteria on the other one. A series of lattice properties are then developed. In a last part, two examples of segmentations are proposed.

Watershed, Hierarchical Segmentation and Waterfall Algorithm

Abstract: A major drawback when using the watershed transformation as a segmentation tool comes from the over-segmentation of the image. Over-segmentation is produced by the great number of minima embedded in the image or in its gradient. A powerful technique has been designed to suppress over-segmentation by a primary selection of markers pointing out the regions or objects to be segmented in the image. However, this approach can be used only if we are able to compute the marker set before applying the watershed transformation. But, in many cases and especially for complex scenes, this is not possible and an alternative technique must be used to reduce the over-segmentation. This technique is based on mosaic images and on the computation of a watershed transform on a valued graph derived from the mosaic images. This approach leads to a hierarchical segmentation of the image and considerably reduces over-segmentation.

Cormas: Common-Pool Resources and Multi-agent Systems

Abstract: This paper describes a simulation environment, called Cormas, that relies on multi-agent systems and has been achieved in Smalffalk, using VisualWorks software Such a simulation tool may prove useful to better understand the complex interactions between natural and social dynamics when studying renewable resource management The general principles of the Cormas platform are first presented, then the implementation is described Two models built with Cormas allow to illustrate the use and the genericity of this tool