LabVIEW interface with Tango control system for a multi-technique X-ray spectrometry IAEA beamline end-station at Elettra Sincrotrone Trieste

A new synchrotron beamline end-station for multipurpose X-ray spectrometry applications has been recently commissioned and it is currently accessible by end-users at the XRF beamline of Elettra Sincrotrone Trieste. The end-station consists of an ultra-high vacuum chamber that includes as main instrument a seven-axis motorized manipulator for sample and detectors positioning, different kinds of X-ray detectors and optical cameras. The beamline end-station allows performing measurements in different X-ray spectrometry techniques such as Microscopic X-Ray Fluorescence analysis (µXRF), Total Reflection X-Ray Fluorescence analysis (TXRF), Grazing Incidence/Exit X-Ray Fluorescence analysis (GI-XRF/GE-XRF), X-Ray Reflectometry (XRR), and X-Ray Absorption Spectroscopy (XAS). A LabVIEW Graphical User Interface (GUI) bound with Tango control system consisted of many custom made software modules is utilized as a user-friendly tool for control of the entire end-station hardware components. The present work describes this advanced Tango and LabVIEW software platform that utilizes in an optimal synergistic manner the merits and functionality of these well-established programming and equipment control tools

Characterization of unique aerosol pollution episodes in urban areas using TXRF and TXRF-XANES

Identifying sources of unique, short-time aerosol pollution episodes in urban areas is a difficult task since they could last only for a couple of hours. With the combination of size-fractioned sampling with May-type cascade impactor and total-reflection X-ray fluorescence (TXRF) in addition to X-ray absorption near-edge structure spectroscopy various sources could be identified in samples collected in Budapest (Hungary) and Cassino (Italy). Using short-time (1–4 h), size-fractionated (70 nm up to 10 μm into 7 stages) sampling method, TXRF is capable of detecting transition metals in the order of 0.1 ng/m3. The present study discusses pollution episodes with Cu and Br concentrations in the range of 1–40 ng/m3. The contribution of both exhaust and non-exhaust type traffic-related emission sources were found to be dominant in the Cu species. Wear products of brake system were identified in coarse particles in addition to resuspension of roadside dust. The ratio of organic/inorganic Br could be determined for a pollution episode with elevated Br concentration

Comprehensive Analysis of Two H13-Type Starting Materials Used for Laser Cladding and Aerosol Particles Formed in This Process

Laser cladding with H13 steel powders was performed and the related material transformations were studied for the particles emitted during this process. Fractions of various sizes of the aerosol particles formed during the laser cladding were collected on a cascade impactor, while the electromobility and the aerodynamic size of the particles were measured using a scanning mobility particle spectrometer and an aerodynamic particle sizer, respectively. The aerosol particles deposited onto the impactor plates were analyzed using scanning electron microscopy–energy-dispersive X-ray spectroscopy, as well as total-reflection X-ray fluorescence and X-ray absorption near-edge structure spectroscopy. Both the concentration and mean oxidation state of the major components were correlated with the aerosol particle size. The ultrafine aerosol particles (with a diameter less than about 100 nm) were predominantly oxidized and formed as the result of an evaporation–oxidation–condensation process sequence. The larger particles (>200 nm in geometric diameter) were primarily the residues of the original metal powder and exhibited a composition change as compared to the as-received metal powder. Correlations between the changes in the concentration ratio of the components were detected and explained

Characterization of the ultrafine and fine particles formed during laser cladding with the Inconel 718 metal powder by means of X-ray spectroscopic techniques

Additive manufacturing is a rapidly growing industrial technology. Still, there is a lack of knowledge regarding the fine particle emission and new particle formation during the processes and their consequences on the performance of the operation and the operator's health as well. Therefore, we studied the properties of the emitted particles during the 3D printing process using the Inconel 718 (Ni-based) superalloy. The number and the mass concentrations were measured with a Scanning Mobility Particle Counter and Sizer. Size-fractionated samples were collected by a cascade impactor, and the elemental composition of the particles was determined by total-reflection X-ray fluorescence analysis, Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and microscopic X-ray fluorescence analysis in the different size fractions. The oxidation states of the metals (Cr, Mn, Fe, Ni) in the samples were determined with the X-ray absorption near-edge structure (XANES) method. Most of the particles were found in the ultrafine region with a size below 100 nm, and the mass size distribution had the maximum at 85 nm. In the original powder, Ni was dominating with appr. 52 wt%, and the proportion of Cr was around 20 wt%, and Mn was below 1 wt%. In the released particles, the Ni content decreased to appr. 26 wt%, the Cr content increased to appr. 47 wt% and Mn increased to around 10 wt% for particles with a size between 0.07 and 10 μm. According to the XANES results, Cr, Mn and Fe were found to be oxidized significantly, whereas Ni remained in the metallic form in the total emitted aerosol containing mostly ultrafine particles. The enrichment and oxidation of metals were correlated with each other

Heavy metals concentrations and speciation of Pb and Ni in airborne particulate matter over two residential sites in Greater Cairo - reflection from synchrotron radiation

Synchrotron radiation-based techniques [X-ray absorption near-edge structure (XANES) and X-ray fluorescence (XRF)] combined with inductively coupled plasma-mass spectrometry (ICP-MS) were used for the assessment of heavy metals concentrations as well as lead (Pb) and nickel (Ni) speciation in airborne particulate matter (PM10) over two residential sites in Greater Cairo. Nineteen 24 h high-volume samples collected at Giza (G) Square and Helwan (H) University (Egypt) were selected for this study. Mean concentrations of heavy metals in PM10 at both sites were found to have the same descending order of Pb > Cu > Ni > Cd > Co > As, of which concentrations of Pb, Cu, Ni and Cd in H samples were higher than those in G samples. For Pb, synchrotron-based XRF results were in good agreement with concentrations obtained by ICP-MS. The XANES spectra of PM10 at the Pb L 2-edge and Ni K-edge were compared with those of Pb and Ni in model standard compounds to provide information on the potential oxidation states as well as the chemical forms of those elements. The data show that Pb has similar chemical environments in both series G and H with the predominance of Pb2+oxidation state. Nickel was found as Ni(OH)2, NiO and Ni metal in the analyzed samples. However, the content of Ni in the background filter shows a very strong interference with that of the collected PM10. Carcinogenic and non-carcinogenic risks resulting from the inhalation of the studied heavy metals were assessed for children and adult residents and were found below the safe limits, at both sites

Adsorption and diffusion of selenite on Boda Claystone Formation

This study provides adsorption and diffusion data of selenite on Boda Claystone Formation (BCF) which is a potential host rock of a deep geological disposal of high-level radioactive waste. The experiments were performed on two diverse core samples: one albitic claystone sample characteristic for the entire BCF and one pyrite containing sample sparsely occurring in BCF. The experiments were carried out under atmospheric conditions. Batch experiments were carried out to study the kinetics of adsorption at a high initial concentration (1.2 × 10−3 M), the adsorption isotherms and reversibility were investigated in the 10−10–10−3 M concentration range. Adsorption onto petrographic thin sections was done to study the elemental distribution on the microscale and the oxidation state of selenium. The maximum of the distribution coefficient was found as Kd ≈ 200 L/kg and a decrease was experienced around 10−6–10−7 M equilibrium concentration, which showed similarities to other argillaceous rocks. Isotopic exchange experiments revealed reversibility of selenite adsorption. Diffusion was studied with through-diffusion and in-diffusion experiments. Using X-ray fluorescence, despite a low initial concentration of 2.3 × 10−5 M in the in-diffusion experiment, a meaningful diffusion profile of selenium could be obtained, from which the selenite apparent diffusion coefficient Dappselenite = (1.5–4.3) × 10−14 m2/s and the selenite rock capacity factor αselenite = 1.4–2.2 were determined. As selenium species are redox sensitive the oxidation state of adsorbed species was studied with X-ray absorption near edge structure spectroscopy on Se–K edge. Adsorbed selenium remained in +IV oxidation state, however reduction was experienced on the pyritic sample

Synchronous bursts on scale-free neuronal networks with attractive and repulsive coupling

This paper investigates the dependence of synchronization transitions of bursting oscillations on the information transmission delay over scale-free neuronal networks with attractive and repulsive coupling. It is shown that for both types of coupling, the delay always plays a subtle role in either promoting or impairing synchronization. In particular, depending on the inherent oscillation period of individual neurons, regions of irregular and regular propagating excitatory fronts appear intermittently as the delay increases. These delay-induced synchronization transitions are manifested as well-expressed minima in the measure for spatiotemporal synchrony. For attractive coupling, the minima appear at every integer multiple of the average oscillation period, while for the repulsive coupling, they appear at every odd multiple of the half of the average oscillation period. The obtained results are robust to the variations of the dynamics of individual neurons, the system size, and the neuronal firing type. Hence, they can be used to characterize attractively or repulsively coupled scale-free neuronal networks with delays.Comment: 15 pages, 9 figures; accepted for publication in PLoS ONE [related work available at http://arxiv.org/abs/0907.4961 and http://www.matjazperc.com/

Socioeconomic inequalities in mortality, morbidity and diabetes management for adults with type 1 diabetes: A systematic review.

AIMS: To systematically review the evidence of socioeconomic inequalities for adults with type 1 diabetes in relation to mortality, morbidity and diabetes management. METHODS: We carried out a systematic search across six relevant databases and included all studies reporting associations between socioeconomic indicators and mortality, morbidity, or diabetes management for adults with type 1 diabetes. Data extraction and quality assessment was undertaken for all included studies. A narrative synthesis was conducted. RESULTS: A total of 33 studies were identified. Twelve cohort, 19 cross sectional and 2 case control studies met the inclusion criteria. Regardless of healthcare system, low socioeconomic status was associated with poorer outcomes. Following adjustments for other risk factors, socioeconomic status was a statistically significant independent predictor of mortality in 9/10 studies and morbidity in 8/10 studies for adults with type 1 diabetes. There appeared to be an association between low socioeconomic status and some aspects of diabetes management. Although only 3 of 16 studies made adjustments for confounders and other risk factors, poor diabetes management was associated with lower socioeconomic status in 3/3 of these studies. CONCLUSIONS: Low socioeconomic status is associated with higher levels of mortality and morbidity for adults with type 1 diabetes even amongst those with access to a universal healthcare system. The association between low socioeconomic status and diabetes management requires further research given the paucity of evidence and the potential for diabetes management to mitigate the adverse effects of low socioeconomic status