Trace elements in the muscle of red shrimp Aristeus antennatus (Risso, 1816) (Crustacea, Decapoda) from Ligurian sea (NW Mediterranean): variations related to the reproductive cycle

Concentrations of total and organic mercury, cadmium, lead, copper, iron, manganese and zinc were determined in the muscular tissue of 135 specimens of Aristeus antennatus (Risso, 1816) collected during a 3-year period in the Ligurian sea (NW Mediterranean). The aim of the present work was to study the relationships between the concentrations of these trace elements and the main biological parameters characterising the organisms, i.e. sex and size with special attention to the sexual maturity of the female specimens. Mercury is the only element showing a significant correlation with the size of the specimens, and for this reason it could give some indications about the age of the shrimps. However, comparison between females collected at four different reproductive phases shows that reproductive individuals are characterised by higher levels of mercury with respect to non-reproductive individuals of the same size.     

Direct coloration of textiles with photochromic dyes. Part 1: Application of spiroindolinonaphthoxazines as disperse dyes to polyester,nylon and acrylic fabrics†

1,3,3‐Trimethylspiroindoline‐2,3′‐3H‐naphth[2,1‐b][1,4]oxazine ( 1a ) and 6′‐piperidino‐1,3,3‐trimethylspiroindoline‐2,3′‐3H‐naphth[2,1‐b][1,4]oxazine ( 1b ) were applied as disperse dyes to polyester, nylon and acrylic fabrics. Under optimised dyeing conditions, photochromic fabrics were produced which, on irradiation with ultraviolet or exposure to sunlight, turned blue ( 1a) or blueish‐purple ( 1b ). Dye 1a showed enhanced photochromic colour change performance compared with dye 1b . The photochromic colour build was highest on nylon and lowest on acrylic fabric. The colour change properties and the technical performance (wash fastness and photostability) of the photochromic fabrics were evaluated using specifically adapted colour measurement methods. The data were analysed in terms of variation of lightness, a*, b*, chroma, hue angle and ΔE, colour difference before and after exposure, and K/S curves as a function of irradiation time. The fabrics generally showed good wash fastness. Although the colour build‐up decreased with exposure to the Xenotest fadeometer, some residual photochromism remained after prolonged exposure.     

The effect of B‐doping on the electrical conductivity of polymer‐derived Si(B)OC ceramics

In this work the room temperature electrical conductivity of Si(B)OC glasses made via polymer pyrolysis at 1200°C and 1400°C (maximum temperature) and having different amount of boron was measured. When B content is increased from zero (pure SiOC glass) up to B/Si=0.5 the electrical conductivity increases in 2 orders of magnitude from 4.09±0.64×10^?5 up to 2.93±1.91×10^?3 with a corresponding decrease in the activation energy from about 1.08 to 0.51 eV. This results shows for the first time that the electrical conductivity of Si‐based polymer‐derived ceramics can be controlled by the amount of the doping element. The structure of the Si(B)OC glasses has been studied with different techniques including FT‐IR, XRD and Raman spectroscopy. The Raman study indicates that B partially substitutes C into the sp² C planes of the free carbon phase forming trigonal BC₃ units. Accordingly, the evolution of the electrical properties with the B content has been correlated with the corresponding structural evolution and a hypothesis is presented to rationalize the role of boron on the electrical conductivity of SiOBC glasses.     

Mass spectrometric analysis of illicit drugs in wastewater and surface water

Residues of illicit drugs have been recently found in urban wastewater and surface water. Their levels reflect the amount of drugs collectively excreted by consumers and can therefore be used to estimate drug abuse. An overview of the most widely used illicit drugs and of the analytical methods used for their detection in wastewater and surface water is presented here. Solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry are the techniques that have been used for these investigations. Instrumental conditions and fragmentation patterns of illicit drugs and their metabolites are described.     

X-ray photoelectron spectroscopy study on the photodegradation of copolyester model compounds

The photodegradation of irradiated PETG and PCCT model compounds namely Tm-CHDM-Tm and Tm-TMCD-Tm, where Tm refers to the methyl ester of terephthalic acid, CHDM refers to 1, 4-cyclohexanedimethanol, and TMCD refers to tetramethyl-1, 3-cyclobutanediol, was analyzed using X-ray photoelectron spectroscopy. Photodegradation products were characterized based on high resolution O_1s x-ray photoelectron spectroscopy (XPS) spectra and the spectra of irradiated model compounds showed a decrease in the relative intensity of C O compared to the CO peak. The percentage of CO formation in irradiated model compounds changed in proportion to irradiation time and showed that the model compound containing CHDM was slightly more UV stable than the TMCD based model compound. Photodegradation mechanisms for model compounds were proposed based on XPS spectra. In parallel studies, density functional theory calculations were performed as an approach to predict degradation products, to help interpreting the XPS spectra of model compounds and characterize the reactivity of model compounds.     

Smolyak's algorithm: a simple and accurate framework for the analysis of correlated log-normal power-sums

The accurate analysis of log-normal power-sums requires the computation of multidimensional integrals with unknown closed-form. Typical approaches to numerically compute them are based on the full tensor-product formula, whose complexity raises exponentially with the number of summands. In this letter, we propose a different method which is called Smolyak's algorithm. It belongs to the family of numerical integration techniques on sparse grids, and can be used in conjunction with several approximation methods for log-normal power-sums. Numerical results will show a complexity reduction greater than 99% without numerical accuracy degradation.     

Comparison of unique hue stimuli determined by two different methods using Munsell color chips

Unique hue stimuli were determined by male and female observers using two different visual experimental procedures involving Munsell color chips of varying hue but identical chroma and value. The hypothesis was that unique hues can be more reliably established by explicit selection from a series of ordered stimuli than implicitly by hue scaling a series of stimuli in terms of neighboring UHs and this was statistically confirmed. The implicit selections based on long term memory of UHs appears to have been more challenging to observers since variability was increased by nearly 50% compared to when UHs were explicitly selected. The ranges of unique hues selected in the two methods were, however, comparable and no statistically significant difference was found between the results of females and males. The intra‐observer variability in picking a stimulus to represent a unique hue, for all observers and averaged for all hues, was approximately 12% of the mean spread of unique hues, confirming that the large inter‐observer variability is driven by differences in color vision and perhaps cognitive processes. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2010