References of "Pirard, Eric"
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See detail3D particles characterization techniques – a review
Pirard, Eric ULg

in International Fine Particle Research Institute (2005)

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See detailRobustness of Planar Shape Descriptors of Particles
Pirard, Eric ULg; Dislaire, Godefroid

in Chung, C.-F. (Ed.) Proceedings Mathematical Geology Congress (2005)

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See detailAdvanced particle characterization for improved understanding of cold spray coating quality
Pirard, Eric ULg; Campana, Florent; Janssen, Jean-Pierre

in Pawlowski, Lech (Ed.) 2e Rencontres Int. Projection Thermique (2005)

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See detailMultispectral imaging of ore minerals in optical microscopy
Pirard, Eric ULg

in Mineralogical Magazine (2004), 68(2), 323-333

Multispectral imaging of ore minerals under the microscope is a logical extension of quantitative colour analysis and microspectrophotometric analysis of minerals. This paper describes, step by step, how ... [more ▼]

Multispectral imaging of ore minerals under the microscope is a logical extension of quantitative colour analysis and microspectrophotometric analysis of minerals. This paper describes, step by step, how the proper calibration of a scientific video camera can be performed in order to obtain precise reflectance measurements at each pixel within the field of view. After having reviewed the different sources of noise and aberration, practical formulae are presented that allow for the acquisition of a set of images at different wavelengths in the visible spectrum. The advantage of using a multispectral image acquisition system based on narrow bandwidth (10 nm) interference filters is discussed and quantitatively compared to colour imaging using tri-stimulus (red, green, blue) filters. Images taken from major sulphide parageneses are shown as examples of well contrasted multispectral images. Finally, the potential for automatic identification of ore minerals is discussed with reference to supervised multivariate image classification algorithms similar to those used in remote sensing. Additional comments on extending the principles for handling optical anisotropy and developing a multiradial imaging system are made. [less ▲]

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See detailInfluence of morphological characteristics of heterogeneous moraine formations on their mechanical behaviour using image and statistical analysis
Lebourg, Thomas; Riss, Joelle; Pirard, Eric ULg

in Engineering Geology (2004), 73(1-2), 37-50

The study of landslide stability on mountain slopes becomes more difficult when the sliding materials. are heterogeneous. This is a current problem with the old glacial moraines now under study in the ... [more ▼]

The study of landslide stability on mountain slopes becomes more difficult when the sliding materials. are heterogeneous. This is a current problem with the old glacial moraines now under study in the Aspe Valley, Pyrenees. Analysis of slope stability numerical models necessitates accurate data about mechanical and physical properties. Because moraines are very heterogeneous, a large sample is necessary, but, unfortunately, data acquisition costs a lot of time and money. Therefore, we would like to estimate mechanical properties from correlated variables that are easier to acquire (morphological variables using image analysis). Observations in the field and previous mechanical results in the laboratory have shown that differences between the behaviour of moraines seem to be related not only to their three-dimensional structure but also to the morphological and petrographical characteristics of their components. The moraines are classified based on textural characteristics at the sample scales based on the distributions of size and shape of their constitutive elements (blocks, matrix, etc.). Then, we study the statistical distribution of the variables to highlight the most significant variables. Next, we evaluate the results of the mechanical behaviour of the moraines, with the internal angle of friction and the effective cohesion. On seven specific moraines, we established relations between the effective internal angle of friction, the elongation factor and the roughness factor. (C) 2003 Elsevier B.V. All rights reserved. [less ▲]

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See detailSegregation of the bulk blend fertilizers
Miserque, Olivier; Pirard, Eric ULg

in Chemometrics and Intelligent Laboratory Systems (2004), 74(1), 215-224

Bulk blend fertilizers are a mixture of different kinds of fertilizers in order to obtain a predicted N-P-K chemical composition. Although this production method has some advantages, segregation appears ... [more ▼]

Bulk blend fertilizers are a mixture of different kinds of fertilizers in order to obtain a predicted N-P-K chemical composition. Although this production method has some advantages, segregation appears at different stages, from the production to the final spreading on the field. An experiment has been implemented to predict and quantify the influence of some physical properties on the occurrence of segregation. The principle was to blend two fertilizers having identical physical properties except for one, such as size, shape or density and to measure the segregation of the blend following various operations, such as filling or emptying a container. Results show that the spread of the fragment size distribution has a big influence on the segregation of the generated heap. In order to reduce this phenomenon, the granulometric spread index (GSI) [(d(84)-d(16))/2d(50)] must be smaller than 10. Other properties don't seem to have an influence. The granulometric segregation can lead to a chemical heterogeneity. The absolute sum of the difference between d(16) and d(84) must be limited around 0.5 mm. Above this value, the chemical segregation begins to be excessive. It seems also that if there is a limited difference in size for the components, the chemical segregation is amplified if the density of the fertilizer with the biggest particles is lower. It is not the case for the difference in shape. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailCartografía de Minerales Evaporiticos Utilizando Imágenes Satelitales de los Salares de Sud Lipez (Bolivia)
Caceres, Fernando; Ali-Ammar, Hamid; Pirard, Eric ULg

in XVI Congreso Geologico Boliviano (2004)

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See detailMonitoring color alteration of ornamental flagstones using digital image analysis.
Lebrun, Vincent; Toussaint, Caroline; Pirard, Eric ULg

in Prykryl, R. (Ed.) Dimension Stone (2004)

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See detailCartografia Preliminar de los minerales evaporiticos del salar de Coipasa utilisando imagenes Aster
Caceres, Fernando; Gutierrez, Jorge; Pirard, Eric ULg

in Conferencia Nacional de Valorizacion de los Salares (2004)

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See detailAnalisis Mineralogico Cuantitativo
Pirard, Eric ULg

in XVI Congreso Geologico Boliviano (2004)

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See detailMultiradial Image Analysis in Optical Reflected Light Microscopy
Pirard, Eric ULg; Lebichot, Sophie

in XIIIth European Congress for Microscopy (2004)

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See detailQuality control of particulate materials through image analysis.
Pirard, Eric ULg

in Optics and Industrial Vision (2004)

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See detailTélédétection et télégestion des informations géologiques : de nouvelles technologies au service du développement.
Pirard, Eric ULg; Caceres, Fernando

in Bulletin des Séances de l’Académie Royale des Sciences d’Outre-Mer = Mededelingen der Zittingen van de Koninklijke Academie voor Overzeese Wetenschappen (2004), 50(3), 321-348

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See detailDirect estimation of sieve size distributions from 2-D image analysis of sand particles
Pirard, Eric ULg; Vergara, Nicolas; Chapeau, Vincent

in Proceedings PARTEC 2004 (2004)

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See detailImage Analysis of Iron Oxides under the Optical Microscope.
Pirard, Eric ULg; Lebichot, Sophie

in Tassinari, L. M.; Pecchio, M.; Andrade, F. R. (Eds.) et al Applied Mineralogy: Developments in Science and Technology (2004)

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See detailImage Measurements
Pirard, Eric ULg

in Francus, P. (Ed.) Image analysis, sediments and paleoenvironments (2004)

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See detailTesting for sources of errors in quantitative image analysis
Francus, Pierre; Pirard, Eric ULg

in Francus, P. (Ed.) Image analysis, sediments and paleoenvironments (2004)

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See detailTeledetección Geológica de la Región de San Pablo de Lipez - Bolivia
Caceres, Fernando; Pirard, Eric ULg

in XVI Congreso Geologico Boliviano (2004)

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See detailMineral mapping in salt lakes from Sud Lipez (Bolivia) using Aster images
Caceres, Fernando; Ali-Ammar, Hamid; Pirard, Eric ULg

in Geological Remote Sensing Group Newsletter (2004), (38), 15-19

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See detailMultivariate discrimination of sands using elongation and abrasivity indices
Pirard, Eric ULg; Vergara, Nicolas

in Proceedings PARTEC (9th European Symposium on Particle Characterization) (2004)

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