Bridging the chasm between MDE and the world of compilation

Modeling and transforming have always been the cornerstones of software system development, albeit often investigated by different research communities. Modeling addresses how information is represented and processed, while transformation cares about what the results of processing this information are. To address the growing complexity of software systems, model-driven engineering (MDE) leverages domain-specific languages to define abstract models of systems and automated methods to process them. Meanwhile, compiler technology mostly concentrates on advanced techniques and tools for program transformation. For this, it has developed complex analyses and transformations (from lexical and syntactic to semantic analyses, down to platform-specific optimizations). These two communities appear today quite complementary and are starting to meet again in the software language engineering (SLE) field. SLE addresses all the stages of a software language lifecycle, from its definition to its tooling. In this article, we show how SLE can lean on the expertise of both MDE and compiler research communities and how each community can bring its solutions to the other one. We then draw a picture of the current state of SLE and of the challenges it has still to face.     

Flash sintering of cationic conductive ceramics: A way to build multilayer systems

Flash Sintering (FS), that allows densifying ceramics at low furnace temperature in a few seconds, requires a reversible electrochemical reaction to enable the current flow through the electrode / material interface. For Li⁺ pure ionic conductors such as Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP), the best material to ensure this fast charge transfer reaction is a mixed Li⁺/e⁻ conductor, eg, LiCoO₂ (LCO). This paper demonstrates the feasibility of FS on LCO between two Pt electrodes and on multi-layers systems using LCO or LATP+LCO composite as electrodes. It is shown that a composite electrode both allows the flash event to occur and prevents the delamination possibly observed with pure LCO by lowering interfacial stresses.     

Some remarks on definitions and, in particular, on the definition of the term calibration

Confucius (Analects xiii:3) ‘It is not possible to haveany valid argument until rigorously defined terms are agreed’. In radiation protection dosimetry, we perhaps need to take asthe fundamental sources of our definitions for personal dosimetryand area monitoring, mainly those three committees—theJoint Committee for Guides in Metrology (JCGM), which givesdefinitions for metrology generally; the International Commissionon Radiation Units and Measurements (ICRU), which gives basicphysical quantities and units for ionising radiation; and theInternational Commission on Radiological Protection (ICRP) forquantities considering the health effect of ionising radiation,for example effective dose, equivalent dose and the qualityfactor/linear energy transfer function. The JCGM, chaired by the Director of the BIPM, is formed bythe seven international organisations that had prepared theoriginal versions of the     

Fractionation of wheat bran carbohydrates

A procedure for the fractionation of wheat bran carbohydrates with an emphasis on non-starchy polysaccharides is described. After a complete extraction using a chloroform-methanol (2:1) solvent, bran was destarched using amyloglucosidase and extracted using ammonium oxalate. Then delignification by sodium chlorite followed by hot water extractions was applied. Small quantities of water-soluble hemicellulosic polymers containing glucose, xylose, arabinose with lesser amounts of galactose and mannose were removed by these three steps. The remaining holocellulose (of a low protein content) was extracted using 1M sodium hydroxide, and hemicelluloses A1 and B1 were separated from the extract. Hemicellulose A1 (5.4% of native bran) was determined to be a xylan containing smaller proportions of arabinose and glucose, whereas hemicellulose B1 (12.6% of native bran) was a complex mixture of several types of polysaccharides, the major one being a highly branched arabinoxylan. Hemicelluloses A4 and B4, obtained by 4M sodium hydroxide extraction of the residue after 1M sodium hydroxide treatment, had lesser amounts of arabinose compared with the respective fractions from the preceding step. For hexoses, higher proportions of mannose and glucose were found. α-Cellulose residue retains 19.8% of pentosans.     

On the promotional effect of Pd on the propene-assisted decomposition of NO on chlorinated Ce0.68Zr0.32O2

The selective catalytic reduction (SCR) of NO_x assisted by propene is investigated on Pd/Ce_0.68Zr_0.32O₂ catalysts (Pd/CZ), and is compared, under identical experimental conditions, with that found on a Pd/SiO₂ reference catalyst. Physico-chemical characterisation of the studied catalysts along with their catalytic properties indicate that Pd is not fully reduced to metallic Pd for the Pd/CZ catalysts. This study shows that the incorporation of Pd to CZ greatly promotes the reduction of NO in the presence of C₃H₆. These catalysts display very stable deNO_x activity even in the presence of 1.7% water, the addition of which induces a reversible deactivation of about 10%. The much higher N₂ selectivity obtained on Pd/CZ suggests that the lean deNO_x mechanism occurring on these catalysts is different from that occurring on Pd⁰/SiO₂. A detailed mechanism is proposed for which CZ achieves both NO oxidation to NO₂ and NO decomposition to N₂, whereas PdO_x activates C₃H₆ via ad-NO₂ species, intermediately producing R-NO_x compounds that further decompose to NO and C_xH_yO_z. The role of the latter oxygenates is to reduce CZ to provide the catalytic sites responsible for NO decomposition. The proposed C₃H₆-assisted NO decomposition mechanism stresses the key role of NO₂, R-NO_x and C_xH_yO_z as intermediates of the SCR of NO_x by hydrocarbons.