The identification and evaluation of natural and synthetic esters in mineral oils

The use of mineral-based lubricating oils blended with vegetable oils or their derivatives has raised the question of the detection, identification, and quantitative evaluation of these substances in formulated products. This paper addresses the problem in a systematic way, and suggests some possible solutions by means of analytical pathways using column chromatography, GLC, and HPLC techniques. The methods suggested allow the identification and evaluation of fatty acid esters with mono- and polyalcohols.     

Scaling of contour-coded binary images

Contour-coded binary images on a discrete square grid can be expanded by means of a simple numerical manipulation of their chain code if they are first decomposed into elementary convex patterns. This approach avoids several shape-interpretation problems, arising with arbitrary blobs, and reduces geometrical distortions to a minimum.     

Solid state polycondensation of poly(butylene terephthalate)

Solid state polycondensation of poly(butylene terephthalate) has been studied under vacuum at 200°C for various particle sizes. The effect of the process on intrinsic viscosity and number of end groups has been examined. The results suggest that the increasing of the number average molecular weight can be explained by a mechanism involving hydroxyl groups, which approach each other by diffusion until a limiting value of their concentration is attained.     

Smoothing with adaptive rank order filters for early processing in image segmentation

This paper describes two non-linear smoothing filters based on adaptive rank order filtering. the ideal output of these filters is a grey value suitable for characterizing the grey value distribution associated with the local texture, i.e. suitable for use as a region label for image segmentation purposes. the problem is to select as output a grey value that is stable with respect to the fluctuations of the local grey value distribution inside homogeneous regions. the first proposed method aims at the estimation of the mode of the local distribution. the second selects the output rank in dependence on the local average; it is simpler and combines the edge-sharpening advantages of ‘comparison and selection filters’ with a better mode estimation, in comparison with the median filter, in the presence of asymmetrical local grey value distributions.     

A windowless water target

A windowless water jet target is described. Working characteristics and “in-beam” performances are presented. An estimate of the thickness of the diffused target associated to water vapour is given.     

Standardization of peeling tests for assessing the cohesion and consolidation characteristics of historic stone surfaces

A peeling test known as the “Scotch Tape test” has been used for more than 40 years in conservation practice for assessing the consolidation efficiency of degraded stone. However, the method has not been supported by any standard or reliably verified recommendations for its application. Its applicability is overestimated, and its unrestricted use without adequate knowledge and sufficient understanding can lead to non-comparable, non-reproducible and, in many cases, incorrect and severely biased results and assessments. This paper presents the results of a recent study focused on establishing limits for application, reliable procedures and a “standard” protocol for testing the cohesion characteristics of brittle and quasi-brittle materials, mainly mortars and stones. The main application strategy exploits repeated peeling in the same place on a surface in order to eliminate the effect of the natural decrease in the detached material from the subsurface layers, which might be incorrectly interpreted as a consolidation effect. There is a discussion of factors influencing the performance of the peeling test method, and examples of peeling measurements on various natural and artificial stones are presented.     

Formation of Monoclinic Hafnium Titanate Thin Films Via the Sol–Gel Method

Hafnium titanate films are generating increasing interest because of their potential application as high- k dielectrics materials for the semiconductor industry. We have investigated sol–gel processing as an alternative route to obtain hafnium titanate thin films. Hafnia-titania films of different compositions have been synthesized using HfCl₄ and TiCl₄ as precursors. The HfO₂–TiO₂ system composition with 50 mol% of TiO₂ and 50 mol% of HfO₂ has allowed the formation of a hafnium titanate film after annealing at 1000°C. The films exhibited a homogeneous nanocrystalline structure and a monoclinic hafnium titanate phase that has never been obtained before in thin films. The films resulted in the formation of homogeneously distributed nanocrystals with an average size of 50 nm. Different compositions, with higher or lower hafnia contents, produced anatase crystalline films after annealing at 1000°C.     

Exposure assessment of fetus and newborn to brominated flame retardants in France: preliminary data

Brominated flame retardants (BFR) are chemicals extensively used in many manufactured products to reduce the risk of fire, but also environmental pollutants. In order to assess the potential risk linked to these compounds in human, a French monitoring study was initiated to evaluate the exposure of fetus and newborn. A previously described multi-residue analytical method was used, for measuring the main classes of BFR (hexabromocyclododecane, tetrabromobisphenol-A, and tri- to deca-polybromodiphenylethers) in various biological matrices. These analyzed samples (maternal and umbilical serum, adipose tissue and breast milk) were collected on volunteer women during caesarean deliveries. Preliminary results obtained on 26 individuals (mother/newborn pairs) mainly demonstrated the presence of polybromodiphenylethers (PBDE) and tetrabromobisphenol A both in maternal and fetal matrices, and a possible risk of overexposure of newborns through breastfeeding. Contaminations levels were found globally in the ng/g lipid weight range, consistent with other published European data. Exposure results regarding highly brominated PBDE congeners (octa- to deca-BDE) appeared particularly informative and non-commonly reported, these compounds accounting for around 50% of the total PBDE load. Additional data collection and metabolism investigations are now on-going. A more complete statistical analysis related to this BFR exposition study will be provided in a next future.