Search results for "confinement"
showing 10 items of 213 documents
Strengthening of Masonry Columns with BFRCM or with Steel Wires: An Experimental Study
2016
Nowadays, innovative materials are more frequently adopted for strengthening historical constructions and masonry structures. The target of these techniques is to improve the structural efficiency with retrofitting methods while having a reduced aesthetical impact. In particular, the use of basalt fiber together with a cementitious matrix emerges as a new technique. This kind of fiber is obtained by basalt rock without other components, and consequently it could be considered a natural material, compatible with masonry. Another innovative technique for strengthening masonry columns consists of applying steel wires in the correspondence of mortar joints. Both techniques have been recently pr…
FT-IR investigation of the state of iron (III) chloride clusters confined in AOT reverse micelles dispersed in carbon tetrachloride
2007
The state of the water-soluble salt iron(III) chloride in AOT reverse micelles dispersed in carbon tetrachloride has been investigated by FT-IR spectroscopy. Interestingly, while the entrapment of a lot of water-soluble inorganic salts in AOT reverse micelles requires preliminarily the presence of significant amounts of water within the micellar core, solubilization of FeCl3 occurs without the need to add water in the micellar solution reaching the very high solubility value, expressed as the maximum salt-to-surfactant molar ratio, of 1.30. The analysis of the spectral features of the investigated samples leads to hypothesize that iron(III) chloride is confined within the reverse micellar c…
R/C columns strengthened by means of steel angles and battens: testing, modeling and design
2010
Chiroptical Phenomena in Reverse Micelles: The Case of (1R,2S)- Dodecyl (2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium Bromide (DMEB)
2014
(1R,2S)-Dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium bromide (DMEB) aggregates dispersed in carbon tetrachloride have been investigated by Fourier transform infrared (FT-IR), vibrational circular dichroism (VCD) and 1H nuclear magnetic resonance (NMR) spectroscopy at various surfactant concentration and water-to-surfactant molar ratio. Experimental data indicate that, even at the lowest investigated concentration and in absence of added water, DMEBmolecules associate in supramolecular assemblies. At higherDMEBconcentration the aggregates can confine watermolecules,making it plausible to think thatDMEB form reverse micelles and that watermolecules are quite uniformly distributed…
1H-NMR and FT-IR study of the state of melatonin confined in membrane models: location and interactions of melatonin in water free lecithin and AOT r…
2004
The state of melatonin confined either in dry lecithin or bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) reversed micelles has been investigated by H-1-NMR and FT-IR spectroscopies as a function of the melatonin to surfactant molar ratio (R). The analysis of experimental results leads to hypothesize that, independently of R and the surfactant nature and as a consequence of anisotropic melatonin/surfactant interactions, melatonin is totally solubilized in reversed micelles and mainly located by opportune orientation in the nanodomain constituted by the surfactant head groups. The absence of significant spectral changes related to the protons linked to the first carbon atoms of surfactant…
Confinement of L and D dimethyl tartrate in reverse micelles: an FT-IR and VCD study
2008
Research on happiness and affect during Covid-19 confinement [Dataset]
2020
Two databases: Research on happiness and affect during Covid-19 confinement
Comment la dégradation de la vie étudiante a-t-elle affecté les manières d’étudier durant la pandémie ?
2021
International audience; Souvent considérée comme privilégiée par rapport aux autres jeunes, la population étudiante apparaît de plus en plus hétérogène en termes de ressources comme de conditions de vie. Les premières enquêtes sur les conséquences de la pandémie ont pointé cette dégradation des conditions de vie et d’études pour une partie de la population étudiante. Cette proposition de communication se base sur l’exploitation d’une enquête sur la vie étudiante durant le premier confinement. Elle s’interroge notamment sur les effets de la dégradation des conditions de vie des étudiants sur leurs manières d’étudier. Le questionnaire a été construit et diffusé en avril 2020. 3 396 personnes …
Les formes résilientes de la convivialité en confinement
2021
International audience; En première analyse, il convient de saisir la mise en tension de la convivialité en confinement, à la fois sous l’angle dramaturgique de pratiques bouleversées au quotidien par le Covid-19 et dans le cadre heuristique de la tensivité qui restitue la dynamique du champ entre les formes de la convivialité, de la table à la convivialité sociale. Une fois posé ce cadre, l’isotopie alimentaire sera retenue comme forme paradigmatique, notamment à travers deux registres figuratifs, la convivialité intra-familiale reconfigurée pendant le confinement et, autre forme résiliente, la convivialité en ligne, avec les apéros virtuels et les liens solidaires connectés, formes de rec…
Protein/Hydration Water Dynamics in Hard Confinement: Dielectric Relaxations and Picoseconds Hydrogen Fluctuations
2011
In this review we report on some experimental studies on the dynamics of Myoglobin in a confined geometry, obtained by encapsulation in a porous silica matrix, at low hydration levels. After formation through the solgel method, the samples were left aging/drying in order to reach a condition where only one or two water layers surround the proteins. In order to put in evidence the specific effect of confinement in the silica host, we compared this system with another one (i.e. hydrated powder) where proteins are confined by other proteins. Using elastic neutron scattering we investigate the temperature dependence of the mean square displacements of non-exchangeable hydrogen atoms of sol-gel …