Angélina Razafitianamaharavo

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Relationships between structural parameters of MnO2 and their surface properties at the solid-gas interface were investigated. The studied series ranged from ramsdellite to pyrolusite and encompassed disordered gamma-MnO2 samples. The structural model used takes into account structural defects: Pr (rate of pyrolusite intergrowth in the ramsdellite network)(More)
BACKGROUND Liposomes are currently an important part of biological, pharmaceutical, medical and nutritional research, as they are considered to be among the most effective carriers for the introduction of various types of bioactive agents into target cells. SCOPE OF REVIEW In this work, we study the lipid organization and mechanical properties of(More)
Al-Fe oxyhydroxy co-precipitates were synthesised by forced hydrolysis of Fe(NO3)3·9H2O and Al(NO3)3·9H2O solutions. Solids containing 0, 1, 10, 25, 50, 75, 90 mol% Al were characterised for composition, texture, mineral structure and local atomic environment. Cation substitution in the hydrous oxides was not observed. The solids consisted of hydrous ferric(More)
Noble gases trapped in meteorites are tightly bound in a carbonaceous carrier labeled “phase Q.” Mechanisms having led to their retention in this phase or in its precursors are poorly understood. To test physical adsorption as a way of retaining noble gases into precursors of meteoritic materials, we have performed adsorption experiments for Ar, Kr, and Xe(More)
The distribution of edge and basal surface areas of phyllosilicate particles is an essential parameter for understanding the interaction mechanisms at solid/gas or solid/liquid interfaces. Among the techniques proposed to determine the geometrical heterogeneities of flat solids, low-pressure argon adsorption and AFM analysis are the most promising to derive(More)
Introduction: Carbonaceous chondrites contain trapped noble gases that are present in different carriers. The most abundant carrier, known as "planetary" also referred to as "Q" or "P1" [1] is formed of carbonaceous material, the nature of which remains ill-defined. It appears to be mainly composed of aromatic moieties linked by short aliphatic chains for(More)
DDB2, known for its role in DNA repair, was recently shown to reduce mammary tumor invasiveness by inducing the transcription of IκBα, an inhibitor of NF-κB activity. Since cellular adhesion is a key event during the epithelial to mesenchymal transition (EMT) leading to the invasive capacities of breast tumor cells, the aim of this study was to investigate(More)
2014 An X-ray and neutron scattering study of C6H12 adsorbed on graphite has been performed from 77 to 260 K. In the monolayer range, three solids have been observed ; they exhibit, in order of increasing density, a commensurate ~7 . ~7 structure (S1), an incommensurate hexagonal structure (S2)’ and a centered rectangular structure (S3 ). The melting(More)
Surface heterogeneity can be assessed by adsorption of different gaseous probes on solid materials. In the present study, four types of activated carbons were analyzed by classical N2 Brunauer-Emmett-Teller (BET) measurements and by low-pressure quasi-equilibrium volumetry (LPQEV) (Villieras, F.; Michot, L. J.; Bardot, F.; Cases, J. M.; Francois, M.;(More)
Textural and energetic proprieties of kaolinite were studied by low-pressure argon adsorption at 77 K. The heterogeneity of four kaolinites (two low-defect and two high-defect samples) modified on their surface by cation exchange with Li+, Na+, or K+ was studied by DIS analysis of the derivative argon adsorption isotherms. The comparison between the(More)