Morphological study of magnesium hydroxide nanoparticles precipitated in dilute aqueous solution

in Journal of Crystal Growth (2003), 249(1-2), 321-330

Among other applications, magnesium hydroxide is commonly used as a flame-retardant filler in composite materials, as well as a precursor for magnesium oxide refractory ceramic. The microstructure of the ... [more ▼]

Among other applications, magnesium hydroxide is commonly used as a flame-retardant filler in composite materials, as well as a precursor for magnesium oxide refractory ceramic. The microstructure of the powder is of prime importance in both technical applications. The influence of synthesis parameters on the morphological characteristics of magnesium hydroxide nanoparticles precipitated in dilute aqueous medium was studied. Several parameters were envisaged such as chemical nature of the base precipitant, type of counter-ion, temperature and hydrothermal treatment. Special attention was given to the obtaining of platelet-shaped, nanometric and de-agglomerated powders. The powders were characterized in terms of particle size distribution, crystal habits, morphology and ability to be redispersed in water. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption and laser diffusion analyses were used for this purpose. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

Morphological variability of some Devonian miospores

in Palaeozoic palynology in space and time. CIMP general meting (2006)

The morphological variation of fossil remains and the problematic notion of palaeontological species: the case of the Atlas bear resolved by ancient DNA analyses

Poster (2006, June)

Because of the morphological variation of the fossil remains, fossil species is a very difficult notion to define in palaeontology. This definition is effectively confronted to numerous problems such as ... [more ▼]

Because of the morphological variation of the fossil remains, fossil species is a very difficult notion to define in palaeontology. This definition is effectively confronted to numerous problems such as body size polymorphism inside a natural population, co-existence of lineages with different morphotypes in a same species. Interestingly, paleogenetics can clarify such ambiguous situations. Size polymorphism and sexual dimorphism were particularly highly pronounced in Ursid populations. Taking as an illustration the extinct populations of brown bear in North Africa, we succeed in addressing the mitochondrial genetic diversity of these Atlas bears and the sexual dimorphism of these samples using molecular typing We are confident that these results will give useful information to palaeontologists in order to revisit the Atlas bears taxonomy and that this approach should be extended to other complex cases of palaeontological species. [less ▲]

Morphological, chromosomal, and genic differences between sympatric Rattus rattus and Rattus satarae in South India

in Journal of Mammalogy (2011), 92(3), 659670

Two morphological forms of black rats (Rattus cf. rattus) were found living in sympatry in high-altitude dense forests of the Nilgiri Mountains, South India. The 1st one, often brown- or gray-bellied ... [more ▼]

Two morphological forms of black rats (Rattus cf. rattus) were found living in sympatry in high-altitude dense forests of the Nilgiri Mountains, South India. The 1st one, often brown- or gray-bellied, also is found commensal in lowland settlements and represents Rattus rattus cf. rufescens (Gray 1837), with a diploid number (2N) of 38 chromosomes. The 2nd form, which has most often a pure white belly, has 2N 5 42 chromosomes and is referable to Rattus r. satarae Hinton, 1918, based on morphological comparison with the holotype. A multidisciplinary study indicates that these 2 forms are characterized by clear-cut differences in biochemistry (electrophoresis of homologous isozymes), molecular sequences (mitochondrial and nuclear DNA), and chromosomes (detailed banding analysis). All these data, coupled to diagnostic morphological characteristics, support the hypothesis that Rattus satarae and Rattus rattus are separate, sympatric species, with no gene flow between them. Their similar external morphology is interpreted as the result of convergence through occupying the same ecological niche. [less ▲]

Morphologie de la mineuse des fruits du safoutier

Poster (2010, July)

L’étude de l’entomofaune des associations culturales prenant en compte le safoutier a permis de mettre en évidence des fortes abondances et une diversité des familles entomologiques. Au niveau des ... [more ▼]

L’étude de l’entomofaune des associations culturales prenant en compte le safoutier a permis de mettre en évidence des fortes abondances et une diversité des familles entomologiques. Au niveau des ravageurs majeurs, nous avons caractérisé un lépidoptère (tortricidae) dont les larves minent les noyaux des fruits du safoutier (Dacryodes edulis) et peuvent induire une chute prématurée d’au moins 25% de fruits. Toutes petites, les larves sont blanches et tachetées de points noirs, puis dans leur dernier stade, elles sont roses avec la tête, les plaque anale et prothoracique brunes. La chrysalide se forme dans un cocon de soie blanc. Elle est brune au départ et noir en fin de nymphose, et se caractérise par un crémaster noir proéminent au milieu de deux paires de soie recourbées à leurs extrémités. La nymphose dure au moins 20 jours. L’adulte est un paillon gris terne. Outre le safoutier, ce lépidoptère a été trouvé dans les fruits de Pseudopdondias longifolia. Des investigations ultérieures révéleront certainement d’autres plantes hôtes et permettront d’envisager une lutte biologique efficiente contre cette mineuse des fruits. [less ▲]

. Morphologie et biométrie comparées des os longs d’Ursus deningeri de la Belle-Roche, d’Ursus arctos et d’Ursus spelaeus

Poster (1990)

La morphologie synchronique du nom latin. Une bibliographie de base (1962-1991)

in Orbis : Bulletin international de documentation linguistique (1993), 36

Morphologie urbaine et économie des services collectifs

Conference (2004, September 17)

La morphologie verbale en néo-égyptien (de la 18e à la 25e dynastie)

Doctoral thesis (1989)

Morphologies et anatomie fonctionnelle et comparées des os longs de Ursus spelaeus, Ursus arctos et Ursus deningeri.

Master's dissertation (1989)