Free-floating molecular clumps and gas mixing: hydrodynamic aftermaths of the intracluster−-interstellar medium interaction

The interaction of gas-rich galaxies with the intra-cluster medium (ICM) of galaxy clusters has a remarkable impact on their evolution, mainly due to the gas loss associated with this process. In this work, we use an idealised, high-resolution simulation of a Virgo-like cluster, run with RAMSES and with dynamics reproducing that of a zoom cosmological simulation, to investigate the interaction of infalling galaxies with the ICM. We find that the tails of ram pressure stripped galaxies give rise to a population of up to more than a hundred clumps of molecular gas lurking in the cluster. The number count of those clumps varies a lot over time -- they are preferably generated when a large galaxy crosses the cluster (M$_{200c} > 10^{12}$ M$_\odot$), and their lifetime ($\lesssim 300$ Myr) is small compared to the age of the cluster. We compute the intracluster luminosity associated with the star formation which takes place within those clumps, finding that the stars formed in all of the galaxy tails combined amount to an irrelevant contribution to the intracluster light. Surprisingly, we also find in our simulation that the ICM gas significantly changes the composition of the gaseous disks of the galaxies: after crossing the cluster once, typically 20% of the cold gas still in those disks comes from the ICM.Comment: 9 pages, 6 figures. Accepted for publication in MNRA

Homogénéisation de matériaux composites pour le blindage électromagnétique

Afin d'alléger la masse des systèmes dans le domaine des systèmes embarqués, le recours à des boîtiers de blindage en matériau composite commence à être envisagé. Malheureusement, les outils numériques classiques tels que Eléments Finis pour modéliser ces systèmes ne peuvent être utilisés car cela mène à un problème numérique trop complexe à résoudre à cause du trop grand écart entre l'échelle des hétérogénéités et celle de la structure. L'utilisation des méthodes d'homogénéisation est alors une solution pertinente pour étudier les matériaux composites. Ce papier présente un modèle d'homogénéisation dynamique valide sur une large gamme de fréquences

Structural Analysis of Partial and Total Esters of Glycerol Undecenoate and Diglycerol Undecenoate

The direct esterification reaction between glycerol and undecylenic acid or between diglycerol and undecylenic acid generates all the possible types of glycerol or diglycerol esters. Purification by silica gel chromatography resulted in the isolation of each of these types of ester in a pure form. The molecular structures of the compounds isolated were characterized and identified by mass spectrometry, 1H NMR, 13C NMR and DEPT‐135. We then studied the composition of esters of undecylenic acid formed with glycerol or diglycerol as a function of their reaction conditions, which constitute a highly complex system. We purified undecylenic acid esters from each polyol family to allow the structural identification of each ester of glycerol and each ester of diglycerol with undecylenic acid. We found that the polarity of these non‐ionic amphiphilic esters directly affected their affinity for organic and inorganic solvents and that these esters behaved very differently from anionic amphiphilic molecules, such as undecylenic acid

Nitrogen sorption as a tool for the characterisation of polysaccharide aerogels

Supercritically dried aerogels of several polysaccharides (chitin, chitosan, alginate, alginic acid, k- carrageenan, and agar) have been characterised by physisorption ofN2. Surface areas as high as 570m2 g−1 have been measured. The nature of the functional groups of the polysaccharide significantly influences the adsorption of N2 on the surface of the aerogel. The net enthalpy of adsorption increases with the polarity of the surface groups of the polymer, in the order chitin < agar≤chitosan < carrageenan < alginic acid∼alginate. The surface area and the mesopore distribution of the aerogels depend both on the dispersion of the parent hydrogel and on the behaviour of each polymer in the drying treatment. Aerogels which retain the dispersion of the parent hydrogel are mainly macroporous (pores larger than 50 nm) while materials liable to shrink upon solvent exchange form mesoporous structures

Ultrasonication as a highly efficient method of flaxseed mucilage extraction

Three methods of aqueous extraction of flaxseed mucilage (magnetic stirring, microwaves and ultrasounds) were compared and tested, from whole flaxseeds at a concentration of 5% (w/v) and a temperature of 50°C. While microwaves are less efficient than a magnetic stirring, ultrasound-assisted extraction showed the highest mass transfer coefficient and a higher order kinetic. 7% of the seed mass were extracted after only 30min of treatment. Ultrasound assisted extraction decreases the intrinsic viscosity of the mucilage from 12.5dL/g (for magnetic stirring) to 6.2dL/g, and the weight-average molecular weight of the largest polysaccharides from 1.5×106Da to 0.5×106Da, whilst having a limited impact on protein content and monosaccharide composition

Effet de l’urée et du NPK 15-15-15 perlés et super granulés sur la productivité des variétés de riz IR841 et NERICA-L14 en zone de bas-fond au Sud-Bénin

Objectives: The study was carried out on the site of Koussin and Lélé in the southern Benin, exploring the efficiency of the supply of the pearl and super granule urea (46%) and NPK 15-15-15 for rice production in the inland valley. Specifically, the study aims to assess the effect of the different forms of urea and NPK 15- 15-15 on the growth and yield parameters of two inland rice varieties (IR841 and NERICA-L14) widely adopted in cultivated lowland of Benin. Methodology and results: The experimental design is a split-plot with two rice varieties, four forms of fertilizer (pearl urea + NPK; pearl urea + super granule NPK; super granule urea + pearl NPK and super granule urea + super granule NPK) in four replications. The growth and yield parameters were assessed. Super granule urea + super granule NPK and super granule urea + pearl NPK have significantly (P &lt; 0.0001) induced higher plant height, numbers of tiller and rice grain per panicle compared with the other treatments whatever the rice variety. However, mean yields of paddy rice and straw were significantly higher (P &lt; 0,0001) for super granule urea + super granule NPK (paddy rice yield : 5,52 ± 0,26 t/ha ; straw yield : 12,19 ± 0,54 t/ha) and super granule urea + pearl NPK (paddy rice yield: 4,82 ± 0,22 t/ha ; straw yield : 10,79 ± 0,61 t/ha). In general with these treatments, the highest yields were recorded with IR841 rice variety. Conclusion and application: The super granule fertilizers are recommended for improving rice production in the inland valley as they improve substantially the yields. In order to improve the efficiency of these fertilizers especially the sources of nitrogen, the study suggests to supply urea super granule + NPK super granule or urea super granule + pearl NPK to improve growth and yields parameter of IR841 rice variety.Keywords: inland valley; super granule fertilizer; soil fertility; irrigated rice production; Benin

ControlMat: A Controlled Generative Approach to Material Capture

Material reconstruction from a photograph is a key component of 3D content creation democratization. We propose to formulate this ill-posed problem as a controlled synthesis one, leveraging the recent progress in generative deep networks. We present ControlMat, a method which, given a single photograph with uncontrolled illumination as input, conditions a diffusion model to generate plausible, tileable, high-resolution physically-based digital materials. We carefully analyze the behavior of diffusion models for multi-channel outputs, adapt the sampling process to fuse multi-scale information and introduce rolled diffusion to enable both tileability and patched diffusion for high-resolution outputs. Our generative approach further permits exploration of a variety of materials which could correspond to the input image, mitigating the unknown lighting conditions. We show that our approach outperforms recent inference and latent-space-optimization methods, and carefully validate our diffusion process design choices. Supplemental materials and additional details are available at: https://gvecchio.com/controlmat/

Esters of oligo-(glycerol carbonate-glycerol): New biobased oligomeric surfactants

Glycerol carbonate is one of the most potentially multifunction glycerol-derived compounds. Glycerol is an important by-product of the oleochemical industry. The oligomerization of glycerol carbonate, assisted by the glycerol, results in the production of polyhydroxylated oligomers rich in linear carbonate groups. The polar moieties of these oligomers (Mw<1000Da) were supplied by glycerol and glycerol carbonate rather than ethylene oxide as in most commercial surfactants. The insertion of linear carbonate groups into the glycerol-based skeleton rendered the oligomers amphiphilic, resulting in a decrease in air/water surface tension to 57mN/m. We improved the physical and chemical properties of the oligomers, by altering the type of acylation reaction and the nature of the acyl donor. The polar head is constituted of homo-oligomers and hetero-oligomers. Homo-oligomers are oligoglycerol and/or oligocarbonate, hetero-oligomers are oligo(glycerol-glycerol carbonate). Coprah oligoesters had the best surfactant properties (CMC<1mg/mL, πcmc<30mN/m), outperforming molecules of fossil origin, such as ethylene glycol monododecyl ether, glycol ethers and fatty acid esters of sorbitan polyethoxylates. The self-assembling properties of oligocarbonate esters were highlighted by their ability to stabilize inverse and multiple emulsions. The oligo-(glycerol carbonate-glycerol ether) with relatively low molecular weights showed properties of relatively high-molecular weight molecules, and constitute a viable “green” alternative to ethoxylated surfactants

The Ikaria high-temperature Metamorphic Core Complex (Cyclades, Greece): Geometry, kinematics and thermal structure

International audienceThis work attempted at clarifying the structure of Ikaria using primarily intensive geological mapping combined with structural analysis and a geothermometry approach of Raman spectrometry of carbonaceous material. Foliation over the whole island defines a structural dome cored by high-grade to partially-molten rocks. Its exhumation was completed by two top-to-the-N ductile extensional shear zones, operating in the ductile and then the brittle fields, through a single extensional event coeval with progressive strain localization. The thermal structure of the dome with regard to position of ductile shear zones was retrieved using the Raman spectroscopy of carbonaceous material. Peak-metamorphic temperatures range from 390 °C in the upper parts of the structure down to 625 °C in the core of the dome in the vicinity of migmatites and S-type granite. Pioneer in situ U-Th-Pb analyses on monazite performed on the leucosome parts of these rock yielded a 15.7 ± 0.2 Ma age. Ikaria Island thus completes the series of Miocene migmatite-cored Metamorphic Core Complex in the central part of the Aegean domain where a genuine high-temperature zone can be defined as the central Aegean HT zone. There, the extreme stretching of the continental crust is associated with dominantly top-to-the-N kinematics