Bruno Valentim

Quantitative colour analysis of beach and dune sediments for forensic applications: A Portuguese example

In this study, the colour of 23 sediment samples collected in different Portuguese beaches in the North (Entre-Douro and Minho) and 33 in the South (Algarve) was tested. Spectral colour parameters (L*a*b*) were measured after several presentation/pre-treatment methods: drying at 40 degrees C, sieving (<150 and <63 microm) and ashing at 850 degrees C, using a Konica Minolta CM-2600d spectrophotometer. A descriptive statistical analysis with L*a*b* values for each presentation/pre-treatment method was performed to ascertain within-sample reproducibility followed by a hierarchical cluster analysis to obtain significant discrimination between samples using colour analysis. The samples analysed presented a colour closest to red and yellow continuums and a lightness close to the pale side of the L*a*b* system colour sphere with samples collected in the North presenting analysis on average darker L values than the samples collected in the South. The cluster analysis, dried, unsieved bulk samples L*a*b* values gave the best discrimination between samples. The clusters analysis dried, unsieved bulk samples-dried, sieved <150 microm fraction set allowed better discrimination between samples compared with the dried, sieved <63 microm fraction set or dried, unsieved bulk samples-ashed bulk, unsieved samples set and even with dried, unsieved bulk samples/dried, sieved <150 microm fraction/dried, sieved <63 microm fraction/ashed bulk, unsieved samples considered all together.

Variations in fly ash composition with sampling location: Case study from a portuguese power plant

Fly ash (FA) is a heterogeneous and complex material resulting from coal combustion in thermoelectric power plants (TPP). Therefore, different types of coals, worldwide, produce FAs with different compositions. However, the location of the FA sampling system, inside the TPP, is also important to the composition of the FA produced at each location. A case study of FA from a Portuguese TPP, using several coal and FA characterization techniques (particle size analysis, proximate and ultimate analyses, XRF, SEM/ESEM/EDS, Optical microscopy, XRD, inferred chemistry, and AAS), has shown that FA chemical classification, mineralogy and phase-mineral classification, and trace elements (Cr, Cu, Mn, Ni, Pb, and Zn) vary due to sampling location. This has implications for improved understanding of the combustion system, as well as in collecting ash products from TPPs for particular market applications. f 2009 The University of Kentucky Center for Applied Energy Research and the American Coal Ash Association All rights reserved. A R T I C L E I N F O Article history: Received 28 October 2009; Received in revised form 4 December 2009; Accepted 9 December 2009

Characterization of soils from the Algarve region (Portugal): A multidisciplinary approach for forensic applications

The Algarve is located at a very short distance from North Africa, in Southern Portugal, and as one of the most touristic regions of Portugal, it is accessible by air, land and sea. It is very susceptible to many illegal activities, such as illegal migration, drug trafficking, kidnapping, and murder, among others. Therefore, an Algarve soils database for forensic purposes is being conducted with the conjunction of geological and palynological methodologies on soils characterization, since this is of fundamental importance to assess reliable evidence on forensic investigations. In this study, the properties of soils from several proximate sites from the Algarve were investigated, namely: (i) colour determined by spectrophotometry; (ii) particle size distribution determined by laser granulometry; (iii) low-field magnetic susceptibility by a susceptibility meter; and (iv) pollen content using a light microscope. Finally, a hierarchical cluster analysis was applied to ascertain the capacity of the different soil properties for discrimination between samples. The study reveals the utility of geobotanical techniques for forensic discrimination of soils. Even though some similarities between some of the samples were found, each one presented a combination of colour, particle size distribution, magnetic susceptibility and pollen features that enable the determination of a fingerprint expected to reveal a specific site for future selection of coastal search areas in the Algarve region.

Raman Microspectroscopy of Genuine and Fake Euro Banknotes

ABSTRACT To evaluate the effectiveness of Raman microspectroscopy in euro banknotes’ recognition, several genuine and fake 10 and 20 euro banknotes were analyzed. Raman microspectroscopy revealed itself to be very useful in the detection of differences in the inks used to provide the color on the banknotes. However, the study revealed that the Raman analysis results are not decisive to guarantee the authenticity of a specific banknote since similar Raman spectra were obtained for genuine and fake banknotes. Even the Raman microspectroscopy analysis obtained for the same color on different areas of fake banknotes revealed similar spectra, and this can help law enforcement agencies to identify counterfeit tracking routes.

The potential application of magnetic susceptibility as a technique for soil forensic examinations

Abstract Magnetic susceptibility measurement methodology, its reproducibility and accuracy of analysis were tested on soil samples to evaluate its potential use in forensic applications. It was observed that magnetic susceptibility can enable discrimination between soil samples, measured values are reproducible over time and the analysis can be carried out on small samples. However, in order for this method to be used in a forensic soil investigation, it is important to always adopt the same analytical protocol during analysis.

High incidence of otolith abnormality in juvenile European flounder Platichthys flesus from a tidal freshwater area

ABSTRACT Otolith abnormality has been reported for a wide range of freshwater and marine fish species. In this study, the sagittal otolith morphology and mineralogy of juvenile European flounder, Platichthys flesus, were examined to describe the incidence and types of structural deformities in this species. Juvenile flounder were collected over the years 2013–2015 in the tidal freshwater section of an estuarine nursery (Minho estuary, NW Portugal). Otolith abnormality was found in 43% of the individuals and, in most cases, occurred in both otoliths. Despite an abnormal mineralogy confirmed by scanning electron microscopy, the morphometry and the mineral polymorph composition of abnormal otoliths did not differ from normal ones (i.e. aragonite). This contrasts with other studies where vaterite and/or calcite were found to replace aragonite in abnormal otoliths. Further studies are needed to elucidate whether abrupt salinity changes associated with habitat transitions may have played a role in the abnormal otolith biomineralization in this species.

Coal Rank Increase and Aerial Oxidation by a Combination of Fourier Transform Infrared Spectroscopy with Multivariate Analysis

ABSTRACT This work describes that the conventional analysis by Fourier transform infrared spectroscopy of a set of coals grouped by means of multivariate analysis (nonlinear mapping and hierarchical cluster analysis) obtained results that show this methodology is a good approach to summarize and classify coals by their structural relationships and the geochemical processes of their origin.

Integration of different sediment characteristics to discriminate between sources of coastal sediments

Abstract In order to investigate the effects of geological setting and the surrounding lithology on coastal sediment samples, four properties were analysed in a series of samples collected from different localities: colour determined by spectrophotometry; particle size distribution determined by laser granulometry; chemical composition determined by ICP-MS (inductively coupled plasma mass spectrometry); and low-field magnetic susceptibility determined using a susceptibility meter. A hierarchical cluster analysis was applied to ascertain the capacity of the different properties for discrimination between samples from the different geological settings. The study reveals that colour analysis only allowed discrimination between different geographical areas; particle size distribution allowed separation between dune and beach samples; chemical composition allowed discrimination between both different geological settings and also between dune and beach sands; and, finally, the combination of magnetic susceptibility with colour and particle size distribution allowed for clear discrimination between geological settings, and between beach and sand dunes. The studied samples are part of a larger and growing collection of data, and a more extensive evaluation will continue to be made for a more definitive assessment of the use of different characteristics for discrimination. So far, the results give confidence that it is meaningful to use these characteristics, especially when examined in combination, to distinguish between different locations.