Evolution of the source apportionment of the lipidic fraction from sediments along the Fensch River, France: a multimolecular approach

The Fensch River (FR) is one of the most contaminated rivers in France due to the population density and the concentration of industrial activities in this small watershed area. From upstream to downstream, the organic matter extracted from sediments has been analyzed by gas chromatography-mass spectrometry and molecules have been quantified and classified into natural, petrogenic, pyrogenic and sewage water (SW) markers. Upstream the river, anthropogenic molecules are already predominant and represent 87.1% of the molecules quantified. This proportion increases from upstream to downstream and rises to 96.8% at the confluence of the FR with the Moselle River. In the upper part of the FR the contamination is mainly due to human waste (coprostanol: 36.44 microg/g; 42.1% of anthropogenic markers). In the lower part, the contribution of SW markers decreases from 42.1 to 2.4% and the proportion of pyrogenic molecules increases from 29.6 to 59.6%. The major sources of pyrogenic organic matter have been determined by calculation of specific ratios on polycyclic aromatic hydrocarbons and by comparison with reported data. Coal tar, road runoff and atmospheric depositions of urban particles seem to be the major pyrogenic sources. Along the river, the proportion of petrogenic molecules remains constant and those molecules seem to be mainly inherited from road runoff, in the upper part of the FR. Industrial lubricants that occur in steel plant sludge are an additional source in the lower part of the river.     

Impact of Blend Morphology on Interface State Recombination in Bulk Heterojunction Organic Solar Cells

This work is a reinvestigation of the impact of blend morphology and thermal annealing on the electrical performance of regioregular‐P3HT:PC₆₀BM bulk heterojunction organic solar cells. The morphological, structural, and electrical properties of the blend are experimentally investigated with atomic force microscopy, X‐ray diffraction, and time‐of‐flight measurements. Current–voltage characteristics of photodiode devices are measured in the dark and under illumination. Finally, the existence of exponential electronic band tails due to gap states is experimentally confirmed by measuring the device spectral response in the subband gap regime. This method reveals the existence of a large density of gap states, which is partially and systematically reduced by thermal annealing. When the band tails are properly accounted for in the drift and diffusion simulations, experimentally measured charge transport characteristics, under both dark and illuminated conditions and as a function of annealing time, can be satisfactorily reproduced. This work further confirms the critical impact of tails states on the performance of solar cells.     

Synthesis and characterization of WO3 thin films by surfactant assisted spray pyrolysis for electrochromic applications

Thin films of WO₃ were prepared by surfactant assisted spray pyrolysis on F-doped SnO₂ (FTO) conductive glass by using hexadecyltrimethylammonium bromide (HTAB) and polyethylene glycol (PEG400):HTAB as growth controlling agents. The surface tension of the spraying solutions was experimentally evaluated and was correlated with the deposition processes (nucleation and growth) of very smooth and homogenous films. The effect of the surfactant, alone and associated with PEG, on the structure (XRD), morphology (AFM), surface composition (XPS), FTIR and hydrophilicity (contact angle) were investigated and their influence on the electrochromic activity was discussed. Using surfactants and PEG, the coloration efficiency, transmission modulation and cycling stability of the WO₃ thin films can be enhanced.     

Double‐Emulsion Globules as a Tool to Produce 2D Patterned Metal Deposits Using Electro‐Colloidal Lithography

A technique developed to self assemble solid colloidal particles under a sinusoidal electric field (AC field) is adapted to soft W/O/W double‐emulsion globules, and is exploited for surface patterning. Double‐emulsions containing cupric ions are prepared, placed between two planar ITO electrodes and submitted to a transversal AC field which induced their ordering into hexagonal 2D‐arrays. The characteristic spacing is monitored by varying the globule volume fraction. Such self‐assembly is used to fabricate copper‐depleted arrays, using globules as both a metal precursor reservoir/provider and as a mask. The ordered globule monolayer is then submitted to a DC field to induce metal precursor leakage and its reduction onto the electrode. The organized, oily and dielectric globules generate arrays of holes (c.a. 7 μm) into a thin copper deposit (thickness of 12 nm). Holes are shown to be formed below the globules, and their separation (from 10 to 30 μm) can be tuned as deduced from direct observations using optical and atomic force microscopy.     

Alumina foam catalyst supports for industrial steam reforming processes

The manufacture and the characterisation of alumina foams as alternative catalysts supports for industrial steam reforming processes are presented here. The possibility of use of alumina foams as catalysts supports in such processes is evaluated by studying their resistance toward mechanical and chemical stresses. The alumina foams produced are characterised owing to their processing parameters (slurry infiltration, sintering temperature, template pore size). Their ability to work in hydrothermal atmosphere is assessed by characterising the evolution of microstructures and mechanical strengths upon aging. Thermodynamic studies of the stability of alumina in industrial steam reforming working conditions are performed and correlated to the experiments to demonstrate the stability of such a system.     

N,N′-alkylated Imidazolium-Derivatives Act as Quorum-Sensing Inhibitors Targeting the Pectobacterium atrosepticum-Induced Symptoms on Potato Tubers

Bacteria belonging to the Pectobacterium genus are the causative agents of the blackleg and soft-rot diseases that affect potato plants and tubers worldwide. In Pectobacterium, the expression of the virulence genes is controlled by quorum-sensing (QS) and N-acylhomoserine lactones (AHLs). In this work, we screened a chemical library of QS-inhibitors (QSIs) and AHL-analogs to find novel QSIs targeting the virulence of Pectobacterium. Four N,N′-bisalkylated imidazolium salts were identified as QSIs; they were active at the μM range. In potato tuber assays, two of them were able to decrease the severity of the symptoms provoked by P. atrosepticum. This work extends the range of the QSIs acting on the Pectobacterium-induced soft-rot disease.     

Determination of parameters in interior permanent-magnetsynchronous motors with iron losses without torque measurement

This paper proposes systematic procedures to estimate the circuit parameters of an inverter-fed vector-controlled interior permanent-magnet synchronous motor when torque measurement is not available. The methodology presented here does not neglect iron losses. New procedures have been developed and justified since international standard recommendations (International Electrotechnical Committee Standards) cannot be applied. Experimental results from a test rig are presented in this paper to validate the most important contributions. Thanks to the procedures proposed, secondary effects on the motor parameters, e.g., saturation or frequency dependency, have been evaluated     

SRAM cell defect isolation methodology by sub micron probing technique

With the complexity of integrated circuitry and the decreasing size of components, usual isolation techniques (SEM inspections, Passive Voltage Contrast…) are not enough to find the defect. This paper presents an accurate methodology using the Sub Micron Probing (SMP) technique applied to a SRAM cell analysis. Indeed the number of non visual defect (NVD) becomes more and more important on the last technologies. In this context, the classical failure analysis must be improved with the electrical methodology. This method consists in using a quantitative electrical I/V characteristic measurement technique at the metallization, vias, and contacts levels during delayering without physical modification and electrical I/V alteration. Moreover, the efficiency of this methodology allows us to guide analysis and to segregate the failure mechanism.