Identification of inorganic pigments used in porcelain cards based on fusing Raman and X-ray fluorescence (XRF) data

Raman spectroscopy and X-ray fluorescence (XRF) spectroscopy are often used as complementary techniques that are well suited for the analysis of art objects because both techniques are fast, sensitive, and noninvasive and measurements can take place in situ. In most of these studies, both techniques are used separately, in the sense that the spectra are evaluated independently and single conclusions are obtained, considering both results. This paper presents a data fusion procedure for Raman and XRF data for the characterization of pigments used in porcelain cards. For the classification of the analyzed points of the porcelain cards principal component analysis (PCA) was used. A first attempt was made to develop a new procedure for the identification of the pigments using a database containing the fused Raman-XRF data of 24 reference pigments. The results show that the classification based on the fused Raman-XRF data is significantly better than the classifications based on the Raman data or the XRF data separately.     

Ultrafast floating 75-V lateral IGBT with a buried hole diverter and an effective junction isolation

A low-voltage lateral insulated gate bipolar transistor (IGBT) is proposed for junction-isolated smart power technologies. An effective suppression of the substrate current is obtained through the use of a double buried layer structure. This structure, with the buried layer of p-type (BLP) on top of the buried layer of n-type, also ensures fast switching and a wide safe operating area as the BLP serves as a buried hole diverter in the on state and during turnoff. The floating capability of the device is also provided by the double buried layer. This lateral IGBT (LIGBT) is made in a standard smart power technology without adding extra masks. Due to the low power losses in the on state and during switching, this n-type LIGBT is competitive with n-type DMOS devices.     

Variability,heterogeneity, and anisotropy in the quasi‐static response of laser sintered PA12 components

Additive manufacturing (AM) receives an increasing industrial interest thanks to its advantages in the economic production of highly complex and small‐series components. Especially laser sintering (LS) is in this context of particular interest for the production of plastic components, as it is generally deemed the most robust AM technology for polymer parts and therefore is expected to enable AM for functional components in the near future. However, to date, designers are often confronted with a severe lack of knowledge on the possible mechanical behavior of AM components. More specifically, the unit‐to‐unit variability, heterogeneity (within‐part variation), and anisotropy of the mechanical properties very often prove to be substantial and therefore require more elaborated studies in order to take these effects into account in the engineering of reliable components. Moreover, typical experimental results that are used for the determination of the elastic stiffness tensor are subject to variability, caused by the influence of the difference in thermal history between produced parts. This work therefore focuses first on the identification and quantification of the variability and heterogeneity in the quasi‐static response of laser sintering‐polyamide 12 (LS‐PA12) components. Second, also the anisotropy in this quasi‐static response is studied. For the first part, uniaxial tensile tests are performed and the variability on the quasi‐static properties is quantified by means of statistical analysis. Also, the elastic stiffness tensor is identified based on these tests. Next, the heterogeneity in the tested specimens is investigated by means of digital image correlation. Finally, in order to study the anisotropy in the quasi‐static properties, the Virtual Fields Method is applied to determine the variability in the elastic stiffness tensor of the LS‐PA12 material. A variability with a coefficient of variance of up to 6.5% on Young's modulus was measured. It was also found that the production planning has an important influence on the homogeneity of the mechanical properties of the produced parts. Finally, the Virtual Fields Method showed that, contrary to most literature on the topic, the elastic properties of LS‐PA12 material is best described using an isotropic material model.     

A Multi-Disciplinary Contribution to the Provenance Determination of Ancient Greek and Roman Marble Artifacts

The problem of determining the provenance of the white marble used for antique artifacts has been tackled in different ways. During the past decade it became clear that a multimethod approach is required to solve the problem. In addition, reliable reference material, i.e., samples collected at the ancient quarry sites in an archaeologically and geologically justified manner, turned out to be a prerequisite for reliable provenance determination. A multimethod approach based on petrography, stable isotope analysis of O and C, and trace element analysis yields complementary information. These methods were applied to the same set of 225 quarry samples. When processed with powerful statistical methods, the data thus obtained allowed all major types of marble used in antiquity to be distinguished. Thus, most problems concerning the provenance of artifacts can be solved. This approach was successfully applied to the provenance determination of about 75 artifacts from different museums in Europe and the USA.     

Precise Measurement of Isotope Ratios with a Double-Focusing Magnetic Sector ICP Mass Spectrometer

The potential of a commercially available double-focusing magnetic sector ICP mass spectrometer (Element, Finnigan MAT, Bremen, Germany) for precise isotope ratio measurement at the low-resolution setting (R = 300) was evaluated. Optimization of scanning conditions led to a relative standard deviation for a set of 10 consecutive 2 min measurements of ～0.1% ((206)Pb(+)/(207)Pb(+)) at signal intensities of ～200?000 counts/s (peak height). This compares favorably with the best values ever reported for quadrupole ICPMS and barely exceeds the theoretical value (counting statistics). Increasing the signal intensity to values ≥500?000 counts/s (peak height) resulted in a further reduction of the RSDs obtained (for both (25)Mg(+)/(26)Mg(+) and (206)Pb(+)/(207)Pb(+)) to typically 0.04%. These figures are remarkably better than those reported for commercially available quadrupole ICPMS systems. This improvement significantly reduces the difference between isotope ratio precision of ICPMS on one hand and those of thermal ionization mass spectrometry and plasma source multiple collector mass spectrometry on the other.     

Determination of platinum and rhodium in environmental matrixes by solid sampling-electrothermal vaporization-inductively coupled plasma mass spectrometry

Electrothermal vaporization from a graphite furnace was used in combination with inductively coupled plasma mass spectrometry (ICPMS) for the determination of Pt and Rh in environmental matrixes. Solid samples of tunnel dust, grass, and atmospheric aerosol collected on a cellulose filter could be analyzed directly, such that sample dissolution-which is not self-evident for the determination of platinum group metals-could be avoided. By heating the graphite furnace according to a multistep temperature program, spectral interferences were avoided, since a "dry" plasma was obtained, while "parent" ions such as Cu, Zn, and Pb, giving origin to interfering molecular ions, were vaporized during the thermal pretreatment step. For tunnel dust, the most demanding sample matrix, a mixture of HCl and HF was used as a modifier to stimulate the vaporization of matrix components during the thermal pretreatment step and, hence, to alleviate matrix-induced analyte signal suppression during the actual vaporization step. Calibration was accomplished by means of single standard addition with an aqueous standard solution. The results obtained agreed within the experimental uncertainty with the corresponding reference values (certified values or results obtained using pneumatic nebulization ICPMS), while relative standard deviations of < or = 15% were typical for both Pt and Rh. In all samples, a Pt/Rh ratio of approximately 6-8 was established. For a typical sample mass of 2 mg, limits of detection were 0.35 ng/g for Pt and 0.05 ng/g for Rh.     

Can dual-headed 18F-FDG SPET imaging reliably supersede PET in clinical oncology? A comparative study in lung and gastrointestinal tract cancer

In this study, we prospectively compared the sensitivity of PET and planar SPET (collimated gamma camera) 18F-FDG imaging in patients with lung and gastrointestinal tract cancer and analysed their respective impact on patient management. Twenty-eight patients with lung cancer and 14 with gastro-intestinal tract tumours were scanned on the same day with a PET and a collimated planar SPET gamma camera. The planar SPET procedure consisted of whole-body planar views and a tomographic acquisition centred over the torso or the abdomen, with the total imaging time within the same range as the whole-body PET procedure. The staging of lung cancer patients was accurate in 86% with PET and 64% with planar SPET. Planar SPET would have led to inappropriate therapeutic decisions in 8 of 28 patients, mainly due to undetected distant metastases. In patients with suspected gastrointestinal tract cancer, planar SPET identified 7 of 15 (47%) proven tumour sites, whereas PET identified 14 of 15 (93%). Our results suggest that collimated planar SPET cameras are not a substitute for dedicated PET scanners. The sensitivity for the detection of tumours is unacceptably low and can impair patient management. The use of multiple tomographic acquisitions could improve the sensitivity but would require a longer scanning time.     

On auto- and cross-interdependence in interval field finite element analysis

This paper discusses the concepts of auto- and cross-interdependence in interval field finite element analysis. In classic interval analysis, independent intervals are used to construct hyper-rectangular input spaces that correspond to the bounded uncertainty that is present on some model parameters. This is a direct result from the inability of modeling interdependence. Such assumption of complete independence might prove in some cases to be highly over-conservative. A first example is the modeling of spatial uncertainty, where the interdependence is governed by allowable spatial gradients of field realizations. Secondly, interdependence can also occur in case uncertainty in several structural quantities has the same root cause (eg, the manufacturing process). Recent work by the authors introduced concepts for modeling dependence between intervals in a spatial and multivariate context. However, it is unclear how an analyst has to deal with multiple quantities that have a spatial uncertainty component and are furthermore interdependent. This paper presents an approach to link multiple interval fields using recently introduced convex hull pair constructions and inverse distance weighting interpolation. Two case studies to illustrate the new methodology are included, proving the flexibility of the methodology in the modeling of auto- and cross-interdependence between multiple interval scalars and/or interval fields.     

Validation of the performance of a GMO multiplex screening assay based on microarray detection

A new screening method for the detection and identification of GMO, based on the use of multiplex PCR followed by microarray, has been developed and is presented. The technology is based on the identification of quite ubiquitous GMO genetic target elements first amplified by PCR, followed by direct hybridisation of the amplicons on a predefined microarray (DualChip^® GMO, Eppendorf, Germany). The validation was performed within the framework of a European project (Co-Extra, contract no 007158) and in collaboration with 12 laboratories specialised in GMO detection. The present study reports the strategy and the results of an ISO complying validation of the method carried out through an inter-laboratory study. Sets of blind samples were provided consisting of DNA reference materials covering all the elements detectable by specific probes present on the array. The GMO concentrations varied from 1% down to 0.045%. In addition, a mixture of two GMO events (0.1% RRS diluted in 100% TOPAS19/2) was incorporated in the study to test the robustness of the assay in extreme conditions. Data were processed according to ISO 5725 standard. The method was evaluated with predefined performance criteria with respect to the EC CRL method acceptance criteria. The overall method performance met the acceptance criteria; in particular, the results showed that the method is suitable for the detection of the different target elements at 0.1% concentration of GMO with a 95% accuracy rate. This collaborative trial showed that the method can be considered as fit for the purpose of screening with respect to its intra- and inter-laboratory accuracy. The results demonstrated the validity of combining multiplex PCR with array detection as provided by the DualChip^® GMO (Eppendorf, Germany) for the screening of GMO. The results showed that the technology is robust, practical and suitable as a screening tool.