Influence of Microstructure and Surface Activation of Dual‐Phase Membrane Ce0.8Gd0.2O2−δ–FeCo2O4 on Oxygen Permeation

Dual‐phase oxygen transport membranes are fast‐growing research interest for application in oxyfuel combustion process. One such potential candidate is CGO‐FCO (60 wt% Ce_0.8Gd_0.2O_2?δ–40 wt% FeCo₂O₄) identified to provide good oxygen permeation flux with substantial stability in harsh atmosphere. Dense CGO‐FCO membranes of 1 mm thickness were fabricated by sintering dry pellets pressed from powders synthesized by one‐pot method (modified Pechini process) at 1200°C for 10 h. Microstructure analysis indicates presence of a third orthorhombic perovskite phase in the sintered composite. It was also identified that the spinel phase tends to form an oxygen deficient phase at the grain boundary of spinel and CGO phases. Surface exchange limitation of the membranes was overcome by La_0.6Sr_0.4Co_0.2Fe_0.8O_3?δ (LSCF) porous layer coating over the composite. The oxygen permeation flux of the CGO‐FCO screen printed with a porous layer of 10 μm thick LSCF is 0.11 mL/cm² per minute at 850°C with argon as sweep and air as feed gas at the rates of 50 and 250 mL/min.     

ASGPR‐Mediated Uptake of Multivalent Glycoconjugates for Drug Delivery in Hepatocytes

Liver cells are an essential target for drug delivery in many diseases. The hepatocytes express the asialoglycoprotein receptor (ASGPR), which promotes specific uptake by means of N‐acetylgalactosamine (GalNAc) recognition. In this work, we designed two different chemical architectures to treat Wilson's disease by intracellular copper chelation. Two glycoconjugates functionalized with three or four GalNAc units each were shown to enter hepatic cells and chelate copper. Here, we studied two series of compounds derived from these glycoconjugates to find key parameters for the targeting of human hepatocytes. Efficient cellular uptake was demonstrated by flow cytometry using HepG2 human heptic cells that express the human oligomeric ASGPR. Dissociation constants in the nanomolar range showed efficient multivalent interactions with the receptor. Both architectures were therefore concluded to be able to compete with endogeneous asialoglycoproteins and serve as good vehicles for drug delivery in hepatocytes.     

Flash Sintering of Nanocrystalline Zinc Oxide and its Influence on Microstructure and Defect Formation

We report the sintering behavior of nanocrystalline zinc oxide under external AC electric field between 0 and 160 V/cm. In situ acquisition of density by means of laser dilatometry, evaluation of specimen temperature, real‐time measurement of electric field and current help analyze this peculiar behavior. Field strength and blocking electrodes significantly affect densification and microstructure, which was evaluated in the vicinity of the flash event and for the fully sintered material. High current densities flow through the sample at high electric fields, entailing a sudden increment of the temperature estimated to several hundreds of K and an exaggerated grain growth. In contrast, low current density flows through the sample at lower electric fields, which guarantees normal grain growth and highest final density. Macroscopic photoluminescence measurements give insights into the development of the defect structure. Electric fields are expected to enhance defect mobility, explaining the high densification rates observed during the sintering process.     

Role of Methyl Salicylate on Oviposition Deterrence in Arabidopsis thaliana

Plants attacked by herbivores have evolved different strategies that fend off their enemies. Insect eggs deposited on leaves have been shown to inhibit further oviposition through visual or chemical cues. In some plant species, the volatile methyl salicylate (MeSA) repels gravid insects but whether it plays the same role in the model species Arabidopsis thaliana is currently unknown. Here we showed that Pieris brassicae butterflies laid fewer eggs on Arabidopsis plants that were next to a MeSA dispenser or on plants with constitutively high MeSA emission than on control plants. Surprisingly, the MeSA biosynthesis mutant bsmt1-1 treated with egg extract was still repellent to butterflies when compared to untreated bsmt1-1. Moreover, the expression of BSMT1 was not enhanced by egg extract treatment but was induced by herbivory. Altogether, these results provide evidence that the deterring activity of eggs on gravid butterflies is independent of MeSA emission in Arabidopsis, and that MeSA might rather serve as a deterrent in plants challenged by feeding larvae.     

Copper‐Catalyzed Trifluoromethylation of Aliphatic N‐Arylhydrazones: A Concise Synthetic Entry to 2‐Trifluoromethylindoles from Simple Aldehydes

The copper‐catalyzed C(sp²) H trifluoromethylation of N,N‐disubstituted hydrazones using the Togni reagent is demonstrated to proceed efficiently for aliphatic aldehyde‐derived substrates. The success of the reactions relied on the choice of the N,N‐diphenylamino group as the terminal hydrazone amino group where N,N‐dialkylamino groups were preferred for (hetero)aromatic aldehyde‐derived substrates. In addition, the trifluoromethylated N‐arylhydrazones are shown to be ideal substrates for Fischer indole synthesis allowing a straightforward, three‐step access to 2‐trifluoromethylindole derivatives from simple aldehydes.

     

Live‐Cell Imaging with Water‐Soluble Aminophenoxazinone Dyes Synthesised through Laccase Biocatalysis

Aminophenoxazinone dyes with variable water solubilities were assayed for the first time in a live‐cell imaging application. Among a library of ten sulfonylated chromophores, one compound gave excellent results as an endocytic marker, showing a precise subcellular distribution. The compound was compared to four commercial vital tracers, including Lucifer Yellow. The first laccase‐mediated regioselective synthesis of a diphosphorylated 2‐aminophenoxazinone dye was also described. This compound, water‐soluble at 10^?2 M , displayed modest fluorescence properties and the ability to complex Mg²⁺ and Ca²⁺ cations, therefore giving fluorescence quenching.     

Naturalistic study of rider's behaviour in initial training in France: Evidence of limitations in the educational content

This paper analyses motorcycle educational content in a number of French motorcycle schools on the basis of a naturalistic study of riders’ and trainers’ behaviour. The aim is to specify the situations delivered in motorcycle schools and to study the rider's activity in these situations. The methodology includes ethnographic observation within the motorcycle schools and the longitudinal monitoring of 14 trainee motorcyclists during their initial training. The training situations were described by the combination of audio–visual recordings and interviews data (i.e. concomitant or interruptive verbalization, and self-confrontation data). The results permit to (1) compare the “real” and “official” durations of track and on-road training, (2) characterize the real training situations, (3) describe the preferred forms of instruction, and (4) conduct an in-depth analysis of the situations used during training in traffic. The discussion show, in first, the poverty of the training situations which are based on the repetition of the exercises in the test, and, in second, disparities between the riding situations encountered during training and the demands made by riding in natural traffic. The usefulness and the applications of this type of approach – based on the integration of the rider's point of view notably by self-confrontation interview – for understanding real riding behaviours and how such approaches could supplement vehicle-based data are discussed in a large conclusion.     

PRESSURIZED ELECTROOSMOTIC DEWATERING IN A FILTER CYCLE

This paper describes the role of pressurized electroosmotic dewatering (EOD) in a filter cycle. A laboratory-scale filter-press was used to filter a highly conductive silica suspension under constant pressure, followed by washing and mechanical precompression of the filter cake and finally by pressurized EOD at constant electric current. The influence of filter cycle parameters (filtration and washing pressure and duration, mechanical pressure, and electric field intensity) on the final cake dryness and energy consumption was studied. Electrodes of different materials, forms, and surfaces were used.

The optimal conditions of each filter cycle operation were found to minimize the energy consumption during EOD and maximize the cake dryness. With mechanical pressure and electric field intensity increasing, the total energy consumption increased, but the specific energy consumption (per kg of expressed water) decreased, and the final filter cake was dryer. The pressurized EOD also used less energy than thermal drying.     

Al2O3-ZrO2 Finely Structured Multilayer Architectures from Suspension Plasma Spraying

Suspension plasma spraying (SPS) is an alternative to conventional atmospheric plasma spraying (APS) aiming at manufacturing thinner layers (i.e., 10-100 μm) due to the specific size of the feedstock particles, from a few tens of nanometers to a few micrometers. The staking of lamellae and particles, which present a diameter ranging from 0.1 to 2.0 μm and an average thickness from 20 to 300 nm, permits to manufacture finely structured layers. Moreover, it appears as a versatile process able to manufacture different coating architectures according to the operating parameters (suspension properties, injection configuration, plasma properties, spray distance, torch scan velocity, scanning step, etc.). However, the different parameters controlling the properties of the coating, and their interdependences, are not yet fully identified. Thus, the aim of this paper is, on the one hand, to better understand the influence of operating parameters on the coating manufacturing mechanisms (in particular, the plasma gas mixture effect) and, on the other hand, to produce Al₂O₃-ZrO₂ finely structured layers with large varieties of architectures. For this purpose, a simple theoretical model was used to describe the plasma torch operating conditions at the nozzle exit, based on experimental data (mass enthalpy, arc current intensity, thermophysical properties of plasma forming gases, etc.) and the influences of the spray parameters were determined by mean of the study of sizes and shapes of spray beads. The results enabled then to reach a better understanding of involved phenomena and their interactions on the final coating architectures permitting to manufacture several types of microstructures.     

Choice of a pertinent color space for color texture characterization using parametric spectral analysis

This article presents a comparison of different color spaces including RGB, IHLS and L?a*b* for color texture characterization. This comparison is based on the fusion of the independent spatial structure and color feature cues. In IHLS and L*a*b*, two channel complex color images are created from the luminance and the chrominance values. For such images, two dimensional complex multichannel linear prediction models are used to perform parametric power spectrum estimation and the structure feature cues are computed from this estimated power spectrum. Quantitative comparison of auto spectra of luminance and combined chrominance channels for different color spaces is done. This comparison is based on the degree of decorrelation between luminance and chrominance information provided by different color space transformations. Three dimensional histograms are used as color feature cues. Then, to classify color textures, Kullback-Leibler divergence based symmetric distance measures are calculated for pure color, luminance structure and chrominance structure feature cues. Individual as well as combined effect of information from all feature cues on classification results is then compared for different color spaces and different color texture data sets. The proposed color texture classification method performs better than the state of the art methods in certain cases. The L*a*b* color space gives us a better characterization of the chrominance spatial structure as well as the overall spatial structure for all of the chosen data sets. Experimental results on pixel classification of color textures are also presented and discussed.