Search results for "RISA"

Electrochemical reactivity of magnesium porphine : functionalization, oligo-polymerization and application to the synthesis of porphyrins and multi-p…

2012

This work deals with the redox reactivity of magnesium porphine, the study of its electropolymerization and resulting materials, of its functionalization by nucleophiles as well as the mechanistic investigation of the C-C oxidative coupling on a tris-meso-substituted porphyrin model.The electrochemical oxidation of magnesium porphine to its cation radical leads to oligomers in solution and polymers on the electrode, which molecular structure depends on the imposed potential. The reactivity of the cation radical has also been exploited by adding sufficient amount of nucleophiles (pyridine and triphenylphosphine) in the reactional in order to inhibit the oligomerization/polymerization process…

Soil Solarization as an Alternative to Methyl Bromide Fumigation for Annual Strawberry Production in a Mediterranean Area

2008

This study compares the effects of soil solarization and methyl bromide fumigation on the growth and yield of strawberry plants (Fragaria xananassa Duch.) cultivated under plastic tunnel conditions. The study was conducted in a Mediterranean coastal area, in four consecutive annual production cycles in a field with no history of methyl bromide fumigation and 2-year history of strawberry production. In all 4 years, solarization was conducted for 7- to 9-week intervals from late June to early September. Cultivar Tudla frigo-plants were planted through mulch in the first week of September of each year. Average daily soil temperatures in solarized plots measured at 15 cm depth were 6.0, 8.1, 7.…

Rehabilitation of Mediterranean anthropogenic soils using symbiotic wild legume shrubs: Plant establishment and impact on the soil bacterial communit…

2010

Abstract Susceptibility to desertification in southern Europe is increasing and rehabilitation of desertification-threatened Mediterranean soils is a challenge due to the inhospitality of the environment. In particular, recovery of anthropogenic soils (mainly human-derived artefacts from housing construction and other inert materials or topsoil of terminal phase municipal landfills) cannot rely on spontaneous processes and low-cost/low-impact strategies are needed to prevent desertification. Mediterranean wild legume shrubs have great potential for soil recovery and conservation against desertification, thanks to drought resistance, and their symbiosis with N2-fixing rhizobia and arbuscular…

A novel TLC based technique for temperature field investigation in MD channel

2011

Effect of preparation method on the properties of poly(methyl methacrylate)/mesoporous silica composites

2019

The preparation method of a polymer composite and the filler loading are amongst the factors that influence the properties of the final composites. This article studies the effect of these factors on the thermal stability and thermal degradation kinetics of poly(methyl methacrylate) (PMMA)/mesoporous silica (MCM-41) composites filled with small amounts of MCM-41. The PMMA/MCM-41 composites were prepared through in situ polymerisation and melt mixing methods, with MCM-41 loadings of 0.1, 0.3, and 0.5 wt.%. The presence of MCM-41 increased the thermal stability of PMMA/MCM-41 composites prepared by melt mixing, but in the case of the in situ polymerised samples, the MCM-41 accelerated the deg…

Biological diversity of the microbial film associated to the central-Mediterranean Dendropoma cristatum (Biondi, 1859) reefs.

2017

Microbial films may provide physical and bio-chemical cues which positively affect the settlement dynamic of a variety of benthic marine organisms, driving the development of ecosystems. Also for the Mediterranean intertidal reef-builder Dendropoma cristatum (Biondi, 1859), biofilm maturity has been found to enhance the settlement pattern. However, the microbial diversity associated with these bioconstructions has never been described. This study investigates the D. cristatum reef bacterial assemblage composition and temporal evolution in two localities in the northwest of Sicily. Biological diversity of the reef-associated biofilm and of 3 progressively older biofims obtained on artificial…

The role of categorization bias in situations of sports and non-sport interaction among Cameroonian footballers migrating to Europe and the Maghreb

2019

The objective of this doctoral work was to consider the difficulties of integration of Cameroonian footballers migrating in Europe and the Maghreb. Starting from the mobilization of a theoretical framework centered on intergroup relations, we questioned the role ofcategorical and identity processes in situations of sporting and non-sporting interactions and their effects on players' behavior.The first exploratory and qualitative study was conducted among Cameroonian footballers who had lived an experience in European or Maghreb clubs. It highlighted the relationship difficulties and forms of discrimination sports and non-sporting which they face, in relation to their ethnic origin. The seco…

Solvent effects on the conformational preferences of model peptoids. MP2 study.

2014

The influence of aqueous environment on the main-chain conformation (ω0, ϕ, and ψ dihedral angles) of two model peptoids: N-acetyl-N-methylglycine N’-methylamide (Ac-N(Me)-Gly-NHMe) (1) and N-acetyl-N-methylglycine N’,N’-dimethylamide (Ac-N(Me)-Gly-NMe2) (2) was investigated by MP2/6-311++G(d,p) method. The Ramachandran maps of both studied molecules with cis and trans configuration of the N-terminal amide bond in the gas phase and in water environment were obtained and all energy minima localized. The polarizable continuum model was applied to estimate the solvation effect on conformation. Energy minima of the Ac-N(Me)-Gly-NHMe and Ac-N(Me)-Gly-NMe2 have been analyzed in terms of the possi…

On the performance of a linearized dual parallel Mach Zehnder electro-optic modulator

2014

The performance of a dual parallel differential Mach-Zehnder modulator broadband linearization architecture is analysed. This study provides experimental and analytical results showing an enhancement up to 20 dB in the 3rd-order intermodulation distortion factor at 5 GHz using RF and optical asymmetrical feeding factors.

Choix d'écoles à Djibouti : une liberté sous contraintes ?

2013

National audience; Cette recherche, fondée sur une enquête de terrain de deux années, interroge les enjeux actuels de l'école de base à Djibouti, sous ses principales déclinaisons. Situant historiquement l'école primaire (publique et privée catholique) d'inspiration occidentale face à son héritage de la colonisation, elle la confronte anthropologiquement à l'éducation traditionnelle d'une part et la renvoie au contexte de scolarisation orientale (école coranique et madrasa) coexistant d'autre part. Une fois définie la typologie scolaire, les éclairages historiques en terme d'éducation traditionnelle et de colonisation permettent de désigner les formes " d'assignations " d'une école de type …