Domain specific language implementation via compile-time meta-programming.

Domain specific languages (DSLs) are mini-languages that are increasingly seen as being a valuable tool for software developers and non-developers alike. DSLs must currently be created in an ad-hoc fashion, often leading to high development costs and implementations of variable quality. In this article, I show how expressive DSLs can be hygienically embedded in the Converge programming language using its compile-time meta-programming facility, the concept of DSL blocks, and specialised error reporting techniques. By making use of pre-existing facilities, and following a simple methodology, DSL implementation costs can be significantly reduced whilst leading to higher quality DSL implementations

Intercalation and grafting of benzene derivatives into zinc-aluminum and copper-chromium layered double hydroxide hosts: An XPS monitoring study

cited By 33International audienceWe report an original strategy to describe, via X-ray photoelectron spectroscopy (XPS) measurements, the interactions between the organic and the mineral sub-systems within a multifunctional hybrid material. A tunable layered double hydroxide (LDH) host system, either a Zn 2Al- or Cu 2Cr-hydrotalcite like compound, is modified with the insertion of the organic guest entities, 4-phenol-sulfonate (HBS) or -carboxylate (HBC). The resulting interactions are studied at two levels: after the organic molecules' insertion in the host LDH (ionic exchange between the LDH counter-ions and the organic anions) and after the condensation (grafting) of the organic species onto the mineral layers when thermally treated. For the inserted material, the main XPS results show a stabilization of the organic molecules within the mineral sheets via H bonding as found elsewhere with FTIR study, the mineral matrix being unchanged. The XPS signal of the organic molecules slightly changes with a widening of core peaks, attesting to some local surrounding modifications. When heating up the Zn 2Al hybrid material, stronger interactions between organic and inorganic systems appeared from around 80 °C with some obvious electronic changes as monitored with the XPS S2p signal of the HBS guest molecules. At the same time, the PXRD pattern clearly shows a decrease of the basal spacing according to a two step contraction process which could be interpreted as a progressive organic molecule condensation onto the inorganic layers via iono-covalent bonds. A copper-chromium LDH is also studied to probe the same kind of interactions with the HBS molecules. The ability of distortion of such mineral material involves a peculiar process of contraction from 40 °C with the immediate and effective anchorage of organic molecules. This journal is © the Owner Societies

Experimental (X-Ray Photoelectron Spectroscopy) and theoretical studies of benzene based organics intercalated into layered double hydroxide

International audienceThe present paper deals with a fine physico-chemical analysis of some hybrid materials combining an inorganic layered double hydroxide phase (LDH) with an organic benzene derivative entity R′-C6H4-R with R = -SO3-, -CO2- and R′ = -H, -OH. The main topic of this work is, in a nanoscale, to propose a way to approach the understanding of the interactions between inorganic and organic sub-systems. The role of the anionic headgroup R is discussed in term of reactivity with the mineral support. The classical expertise of materials via the PXRD technique puts into light an effective LDH interlayer space enlargement with the organics incorporation and a minimum angle of inclination for every organics within the LDH matrix. The originality of this study is to use the X-Ray Photoelectron spectroscopy (XPS) as a local probe of the chemical environments of the headgroup of the organic entities. In a parallel way, some quantum calculations (by using molecular and periodical codes) are carried out to best appreciate the electronic and structural evolutions before and after the intercalation step. A specific reactivity of the -SO3- group compared with the -CO2- one is evidenced. Moreover, a correlation at the first order is then set up between the net charges of atoms and the XPS binding energies of their core levels

Size dependent dipolar interactions in iron oxide nanoparticle monolayer and multilayer Langmuir-Blodgett films

The dipolar interactions in monolayer and multilayer assemblies of iron oxide nanoparticles have been investigated as a function of the nanoparticle size. The magnetic properties of iron oxide nanocrystals of various sizes have been measured for particles as powders and assembled in mono-and multilayers by the Langmuir-Blodgett technique, and compared to the behavior of non-interacting nanoparticles. It is shown that increasing dipolar interactions lead to higher blocking temperatures and to deviation from the Neel-Brown law. Dipolar interactions are found to be stronger for particles assembled in thin films compared to powdered samples. The effect of interactions increases strongly with the nanoparticle size in agreement with simulations, leading to an unusual behaviour for the larger particles assembled in monolayer, which could be a signature of a superferromagnetic state.Financial support was provided by the Agence Nationale pour la Recherche (ANR MAGARRAYS) and the Direction Générale de l’Armement (DGA). The authors thank Cedric Leuvrey for SEM pictures, Dris Ihiawakrim and Corinne Ulhaq for TEM pictures, Christophe Lefevre for XRD refinement, and Alain Derory for technical support with SQUID measurements

Percolation network of organo-modified layered double hydroxide platelets into polystyrene showing enhanced rheological and dielectric behavior

International audienceA hybrid organic inorganic layered double hydroxide incorporating 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) is characterized by means of XRD, FTIR, and XPS. The in situ polymerization is scrutinized by 13C CPMAS as well as by a set of XRD experiments with varying temperature. It is found that the in situ polymerization is complete at 200 °C, and the hybrid framework sustains temperatures as high as 350 °C. Direct incorporation of poly(AMPS) is reported and the resulting hybrid LDH phases studied. Subsequently, all generated hybrid platelets are used as organo-modified 2D-type filler dispersed into polystyrene (PS). An immiscible PS composite structure with salient gel-like viscoelastic properties is obtained after bulk polymerization. In the low-frequency region, the typical Newtonian flow behaviour of PS is found to change progressively against filler loading into a shear-thinning behaviour evidenced by a pseudo-plateau in the elastic and loss modulus curves and associated with a shift of the glass transition temperature of PS to higher temperature. It is interpreted by hybrid LDH platelet domains presenting a large interface with the polymer, thus having the effect of restricting the plastic deformation by obstructing polymer chain motion. Such dispersed hybrid LDH tactoids forming a three-dimensional percolated network are indirectly evidenced by the enhancement of the dielectric properties illustrated by an increase in bulk dc conductivity of about one order at room temperature and in the dissipation factor. The study shows that hybrid LDH assembly is of relevance in topical applications regarding mechanical reinforcement as well as electrostatic energy dissipation. © 2010 The Royal Society of Chemistry

Phosphate structure and lithium environments in lithium phosphorus oxynitride amorphous thin films

Lithium ion-conducting glasses attract wide interest for electrochemical applications like efficient energy storage devices. This work presents a structural study on involved bonding units, based on X-ray photoelectron spectroscopy and infrared spectroscopy, of lithium phosphorus oxide and oxynitride amorphous thin films prepared by RF magnetron sputtering. A thorough consideration of the mid- and far-infrared spectral regions demonstrated structural changes at the phosphate units and the lithium ion environments triggered by nitrogen incorporation and post-deposition thermal treatment. It was found that films prepared by sputtering in pure nitrogen atmosphere have about 75 % of their nitrogen atoms in sites doubly coordinated with phosphorus (P–N=P), and the rest in triply coordinated sites. It was shown also that nitrogen incorporation favors the stability of lithium ions, while annealing enhances ionic conductivity of the oxynitride films

Effect of the nanoparticle synthesis method on dendronized iron oxides as MRI contrast agents

Aqueous suspensions of dendronized iron oxide nanoparticles (NPs) have been obtained after functionalization, with two types of dendrons, of NPs synthesized either by coprecipitation (leading to naked NPs in water) or by thermal decomposition (NPs in situ coated by oleic acid in an organic solvent). Different grafting strategies have been optimized depending on the NPs synthetic method. The size distribution, the colloidal stability in isoosmolar media, the surface complex nature as well as the preliminary biokinetic studies performed with optical imaging, and the contrast enhancement properties evaluated through in vitro and in vivo MRI experiments, have been compared as a function of the nature of both dendrons and NPs. All functionalized NPs displayed good colloidal stability in water, however the ones bearing a peripheral carboxylic acid function gave the best results in isoosmolar media. Whereas the grafting rates were similar, the nature of the surface complex depended on the NPs synthetic method. The in vitro contrast enhancement properties were better than commercial products, with a better performance of the NPs synthesized by coprecipitation. On the other hand, the NPs synthesized by thermal decomposition were more efficient in vivo. Furthermore, they both displayed good biodistribution with renal and hepatobiliary elimination pathways and no consistent RES uptake