Influence of biological and ecological factors on the bioaccumulation of polybrominated diphenyl ethers in aquatic food webs from French estuaries

Previous studies have shown the worldwide presence of six congeners of polybrominated diphenyl ethers (PBDEs) in marine biota (BDE-28, -47, -99, -100, -153 and -154). The objective of the present study was to document their presence, their level and their transfer in the food web of two major estuaries in France, the Loire and the Seine. PBDEs were quantified in eight principal species from the Loire, representing primary consumers (the bivalve Scrobicularia plana), omnivores (the worm Nereis diversicolor, the shrimps Crangon crangon, Palaemon elegans and Palaemon serratus, the flatfish Platichthys flesus and Solea solea) and supercarnivores (the eel Anguilla anguilla). In the Seine, only worms, bivalves, sole and eels have been studied. Parameters, which can interfere with the interpretation of contamination data (organ distribution, influence of weight or size of specimens, lipid richness, intrinsic variability), have been examined. BDE-47 was the predominant congener in all biota. Higher contamination was observed in most of the species collected from the Seine, in agreement with the higher human presence and economic activity in the Seine than in the Loire basin. PBDEs have been shown to biomagnify in both of the studied estuarine food webs. However, assessment of PBDE transfer from seafood products exposed to contaminants in the Seine estuary showed that human daily intake is far below the no observed adverse effect levels.     

Engineered slope failure susceptibility modelling using high spatial resolution geospatial data

Bulletin of Engineering Geology and the Environment - Given the increased hazards faced by transport corridors such as climate induced extreme weather, it is essential that local spatial hotspots...     

Dyeing plants screening: an approach to combine past heritage and present development

The paper reports an investigation of the colouring properties of 43 dyeing plants chosen for their widespread use in previous centuries. Colorimetric analysis showed that the principal colours on different fabric supports were yellow and mostly unsaturated. The nature of the support fibres investigated, protein- or cellulose-based, was shown to play an important role in the perceived colours. Phytochemical analysis confirmed that yellow-orange shades could be attributed to flavonoids and that red colours were due to anthraquinones. Colours from plants that contain anthocyanins varied from blue-violet through reddish depending on the structure of the anthocyanins in the individual plants. Colour fastness was determined by applying standard test methods. Fastness to light appeared to be inadequate for industrial applications for most samples, but it seems that this could be improved by certain molecular associations. On the other hand, colour fastness to water was satisfactory.     

Optimization of Nannochloropsis oculata growth using the response surface method

Optimization of Nannochloropsis oculata growth was undertaken using the response surface method. A central composite design was defined to study the effects of temperature, pH, incident light intensity and aeration rate on the maximum growth rate of the microalga. Using statistical analysis, the first model calculated to fit results was twice improved. The final model obtained was used to clarify the effects of each factor and their interactions on the growth of Nannochloropsis oculata. The optimum growth conditions of this microorganism were also estimated as 21 °C, 52 µmol photons m^?2 s^?1, pH 8.4 and 14.7 VVH of aeration rate. These conditions were tested and validated experimentally since the maximum growth rate achieved with these parameters, 0.0359 h^?1, is the best reported in this study. Copyright © 2006 Society of Chemical Industry     

The imposter phenomenon: Recent research findings regarding dynamics, personality and family patterns and their implications for treatment.

Reviews research on the impostor phenomenon, an experience of feeling incompetent and of having deceived others about one's abilities. Impostor feelings are shown to be associated with such characteristics as introversion, trait anxiety, a need to look smart to others, a propensity to shame, and a conflictual and nonsupportive family background. The findings are discussed in terms of self psychological theory, with the impostor phenomenon seen as a result of seeking self-esteem by trying to live up to an idealized image to compensate for feelings of insecurity and self-doubt. Therapeutic approaches drawing on self psychology and cognitive therapy are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of steric effects in the adsorption of chemically similar probes to a poly(methyl methacrylate) surface

The role of steric effects in the adsorption of chemically similar acidic probes to the model basic surface of poly(methyl methacrylate) (PMMA) was examined using the technique of inverse gas chromatography (IGC). The results were expressed in terms of the acid-base contribution to the Gibbs free-energy change upon adsorption. The acid-base component of the adsorption free energy, computed on the basis of theoretical modes of adduct formation, was found to depend strongly on the molecular structure of the adsorbate, suggesting the importance of steric effects. © 1994 John Wiley & Sons, Inc.     

Design and Performance of an Integrated Analytical Swatch Testing System

Abstract

An integrated swatch testing system for precisely quantifying the resistance of chemical protective materials to permeation and penetration by a chemical weapons agent (CWA) simulant is described. The analytical variability of methodologies currently used by Department of Defense testing laboratories was dramatically reduced by modifying the test cell and experimental procedures while maintaining compatibility with military testing specifications. Utilizing an on-line calibration system, cryogen-free preconcentrator, and flame ionization detector, the integrated system has demonstrated excellent repeatability, reproducibility, and high sampling frequency for a variety of non-porous and air-penetrable swatch samples challenged with methyl salicylate.     

Preparation of PEDOT-ordered mesoporous carbon hybrid material using vapor phase polymerization

A hybrid composite was prepared by the formation of poly (3,4-ethylenedioxythiophene) (PEDOT) layer on two types of ordered mesoporous carbon (OMC) by vapor phase polymerization. The morphology, chemical composition, pore structure, and electrical properties of the normal type ordered mesoporous carbon (NTOMC) and rod type ordered mesoporous carbon (RTOMC) composites were compared and analyzed. The surface morphology of the PEDOT-OMC composite did not change, due to the uniform coating of PEDOT layer on the OMC. The content of PEDOT in the composite and the thickness of the coating layer both increased with the amount of the oxidizing agent, Iron (III) p-toluenesulfonate (FTS) used in VPP. Pore size, porosity, and surface area of PEDOT-OMC composite decreased with coating of PEDOT layer on the outer surface of the OMC, and the mesopore inner wall. Electrical resistance decreased with an increase in the thickness of the PEDOT layer coated on the OMC. The PEDOT-RTOMC composite had lower electrical resistivity than the PEDOT-NTOMC composite, suggesting that rod-type morphology is advantageous for electron transport. The capacitance was also higher for the PEDOT-RTOMC than for the PEDOTNTOMC, which is thought to be proportional to the surface area of the composite determined by the external and internal structure of the material.     

Control of Switching Modes and Conductance Quantization in Oxygen Engineered HfOx based Memristive Devices

Hafnium oxide (HfO_x)‐based memristive devices have tremendous potential as nonvolatile resistive random access memory (RRAM) and in neuromorphic electronics. Despite its seemingly simple two‐terminal structure, a myriad of RRAM devices reported in the rapidly growing literature exhibit rather complex resistive switching behaviors. Using Pt/HfO_x/TiN‐based metal–insulator–metal structures as model systems, it is shown that a well‐controlled oxygen stoichiometry governs the filament formation and the occurrence of multiple switching modes. The oxygen vacancy concentration is found to be the key factor in manipulating the balance between electric field and Joule heating during formation, rupture (reset), and reformation (set) of the conductive filaments in the dielectric. In addition, the engineering of oxygen vacancies stabilizes atomic size filament constrictions exhibiting integer and half‐integer conductance quantization at room temperature during set and reset. Identifying the materials conditions of different switching modes and conductance quantization contributes to a unified switching model correlating structural and functional properties of RRAM materials. The possibility to engineer the oxygen stoichiometry in HfO_x will allow creating quantum point contacts with multiple conductance quanta as a first step toward multilevel memristive quantum devices.