Automotive catalytic converters, in which Pt, Pd and Rh (platinum-group elements; PGEs) are the active components for eliminating several noxious components from exhaust fumes, have become the main ...source of environmental urban pollution by PGEs. This work reports on the catalyst morphology through changes in catalyst surface by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) and laser-induced breakdown spectrometry (LIBS) from fresh to aged catalytic converters. The distribution of these elements in the fresh catalysts analysed (Pt–Pd–Rh gasoline catalyst) is not uniform and occurs mainly in a longitudinal direction. This heterogeneity seems to be greater for Pt and Pd. PGEs released by the catalysts, fresh and aged 30
000 km, were studied in parallel. Whole raw exhaust fumes from four catalysts of three different types were also examined. Two of these were gasoline catalysts (Pt–Pd–Rh and Pd–Rh) and the other two were diesel catalysts (Pt). Samples were collected following the 91441 EUDC driving cycle for light-duty vehicle testing. The results show that at 0 km the samples collected first have the highest content of particulate PGEs and although the general tendency is for the release to decrease with increasing number of samples taken, exceptions are frequent. At 30
000 km the released PGEs in gasoline and diesel catalysts decreased significantly. For fresh gasoline catalysts the mean of the total amount released was approximately 100, 250 and 50 ng km
−1 for Pt, Pd and Rh, respectively. In diesel catalysts the Pt release varied in the range 400–800 ng km
−1. After ageing the catalysts up to 30
000 km, the gasoline catalysts released amounts of Pt between 6 and 8 ng km
−1, Pd between 12 and 16 ng km
−1 and Rh between 3 and 12 ng km
−1. In diesel catalysts the Pt release varied in the range 108–150 ng km
−1. The soluble portion of PGEs in the HNO
3 collector solution represented less than 5% of the total amount for fresh catalysts. For 30
000 km the total amount of soluble PGEs released was similar or slightly higher than for 0 km.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
52.
Small-pads resistive micromegas Alviggi, M.; Biglietti, M.; Canale, V. ...
Journal of instrumentation,
03/2017, Volume:
12, Issue:
3
Journal Article
An inductively coupled plasma mass spectrometer (ICP-MS), equipped with a dynamic reaction cell (DRC) and coupled with a desolvating nebulizing system (Apex-ACM) to reduce the oxide formation, was ...used in the determination of Al, Co, Cr, Mn, Ni and Se in serum samples. The effect of the operating conditions of the DRC system was studied to get the best signal-to-background (S/B) ratio. The potentially interfering molecular ions at the masses m/z27Al, 59Co, 52Cr, 55Mn, 60Ni and 78Se, were significantly reduced in intensity by using NH3 and H2, as the reaction cell gases in the DRC, while a proper Dynamic Bandpass Tuning parameter q (RPq) value was optimized. The detection limits for 27Al, 59Co, 52Cr, 55Mn, 60Ni and 78Se, estimated with 3-sigma method, resulted to be 0.14, 0.003, 0.002, 0.01, 0.01 and 1.8 microg L(-1), respectively. This analytical method was developed on both a human serum certified reference material and a lyophilized animal serum produced and proposed in an intercomparison study. The results obtained for the reference samples agreed satisfactorily with the certified values. Precision (expressed as CV%) between sample replicates was better than 10% for elements determination, with the only exception of aluminium (14%).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Gigatracker (GTK) is a hybrid silicon pixel detector designed for the NA62 experiment at CERN. The beam spectrometer, made of three GTK stations, has to sustain high and non-uniform particle rate ...(∼1GHz in total) and measure momentum and angles of each beam track with a combined time resolution of 150ps. In order to reduce multiple scattering and hadronic interactions of beam particles, the material budget of a single GTK station has been fixed to 0.5% X0. The expected fluence for 100 days of running is 2×1014 1MeVneq/cm2, comparable to the one foreseen in the inner trackers of LHC detectors during 10 years of operation. To comply with these requirements, an efficient and very low-mass (<0.15%X0) cooling system is being constructed, using a novel microchannel cooling silicon plate. Two complementary read-out architectures have been produced as small-scale prototypes: one is based on a Time-over-Threshold circuit followed by a TDC shared by a group of pixels, while the other makes use of a constant-fraction discriminator followed by an on-pixel TDC. The read-out ASICs are produced in 130nm IBM CMOS technology and will be thinned down to 100μm or less. An overview of the Gigatracker detector system will be presented. Experimental results from laboratory and beam tests of prototype bump-bonded assemblies will be described as well. These results show a time resolution of about 170ps for single hits from minimum ionizing particles, using 200μm thick silicon sensors.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Involvement of metals in the risk of developing Parkinson's disease (PD) has been suggested. In the present study, concentration of metals in cerebrospinal fluid (CSF), blood, serum, urine and hair ...of 91 PD patients and 18 controls were compared.
Blood and hair were microwave digested, while CSF, serum and urine were water-diluted. Elements quantification was achieved by Inductively Coupled Plasma Atomic Emission Spectrometry and Sector Field Inductively Coupled Plasma Mass Spectrometry.
Some metal imbalances in PD were observed:
i), in CSF, lower Fe and Si;
ii), in blood, higher Ca, Cu, Fe, Mg and Zn;
iii), in serum, lower Al and Cu;
iv), in urine, lower Al and Mn, higher Ca and Fe; and
v), in hair, lower Fe. The ROC analysis suggested that blood Ca, Fe, Mg and Zn were the best discriminators between PD and controls. In addition, hair Ca and Mg were at least 1.5 times higher in females than in males of patients and controls. A decrement with age of patients in hair and urine Ca and, with less extent, in urine Si was observed. Magnesium concentration in CSF decreased with the duration and severity of the disease. Elements were not influenced by the type of antiparkinsonian therapy.
Variation in elements with the disease do not exclude their involvement in the neurodegeneration of PD.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
57.
May 14C be used to date contemporary art? Fedi, M.E.; Caforio, L.; Mandò, P.A. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
January 2013, 2013-01-00, 20130101, Volume:
294
Journal Article
Peer reviewed
The use of radiocarbon in forensics is by now widespread, thanks to the so-called bomb peak, which makes it possible to perform high-precision dating. Since 1955, 14C concentration in the atmosphere ...had strongly increased due to nuclear explosions, reaching its maximum value in 1963–1965. After the Nuclear Test Ban Treaty, 14C started to decrease as a consequence of the exchanges between atmosphere and the other natural carbon reservoirs. Nowadays, it is still slightly above the pre-bomb value. The work presented in this paper is based on the idea of exploiting the bomb peak to “precisely” date works of contemporary art, with the aim at identifying possible fakes.
We analysed two kinds of materials from the 20th century: newspapers and painting canvases. Newspaper samples were taken because they might in principle be considered to represent dated samples (considering the date on the issues). Our data (28 samples) show a trend similar to atmospheric data in the literature, although with some differences; the paper peak is flatter and shifted towards more recent years (about five years) with respect to the atmospheric data. This can be explained by taking paper manufacturing processes into account. As to the canvas samples, the measured 14C concentrations were generally reasonably consistent with the expected concentrations (based on the year on the paintings). However, this does not indicate that the interpretation of the results is simpler and more straightforward. Obviously, we only measure the 14C concentration of the fibre used for the canvas, which does not necessarily measure the date the painting was manufactured.
In this paper, sample preparation and experimental results will be discussed, in order to show the potential as well as the limitations of radiocarbon to date contemporary art.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Quantifications of Al, Ca, Cu, Fe, Mg, Mn, Si and Zn were performed in urine, serum, blood and cerebrospinal fluid (CSF) of 26 patients affected by Parkinson's disease (PD) and 13 age-matched ...controls to ascertain the potential role of biological fluids as markers for this pathology. Analyses were performed by Inductively Coupled Plasma Atomic Emission Spectrometry and Sector Field Inductively Coupled Plasma Mass Spectrometry. The serum oxidant status (SOS) and anti-oxidant capacity (SAC) were also determined. Results showed a decreasing trend for Al in all the fluids of PD patients, with the strongest evidence in serum. Calcium levels in urine, serum and blood of PD patients were significantly higher than in controls. Copper and Mg concentrations were significantly lower in serum of PD patients. Levels of Fe in urine, blood and CSF of patients and controls were dissimilar, with an increase in the first two matrices and a decrease in CSF. No significant difference was found in levels of Mn between patients and controls. Urinary excretion of Si was significantly higher in PD subjects than in controls. No clear difference between Zn levels in the two groups was found for serum, urine or CSF, but an increase in Zn levels in the blood of PD patients was observed. The SOS level in PD was significantly higher while the corresponding SAC was found to be lower in patients than in controls, in line with the hypothesis that oxidative damage is a key factor in the pathogenesis of PD. The results on the whole indicate the involvement of Fe and Zn (increased concentration in blood) as well as of Cu (decreased serum level) in PD. The augmented levels of Ca and Mg in the fluids and of Si in urine of patients may suggest an involuntary intake of these elements during therapy.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The capability of alloys used in cheap jewellery to release metal ions on contact with the skin causing allergic contact dermatitis (ACD) is generally acknowledged. To reduce the diffusion of the ...Ni-induced ACD the Council Directive 94/27/EC Council Directive 94/27/EC of 30 June 1994. Official Journal L 188, 22/07/1994, 1. limited the total Ni content in alloys and its release rate in artificial sweat. In this work, three different aspects were explored: i) the frequency of skin sensitization to Ni-containing earrings in patients before and after the introduction of the Directive's limit; ii) metal composition of alloys by X-ray analysis; iii) metal leaching in artificial sweat followed by Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS) quantification. Well-known allergenic metals, as Ni, Cr and Co, and possible emergent allergens, as Al, Ag, Au, Cd, Cu, Fe, Ir, Mn, Pb, Pd, Pt, Rh, Sn, V and Zn, were studied.
Results showed that the frequency of allergy due to earrings did not decrease after the introduction of the Ni limit: in 1994 and in 2005 patients positive to Ni patch tests were 54.3% and 53.5%, respectively. The earring components analyzed were Fe-based or alloys of Cu/Zn or Fe/Cr/Ni, plated with a thin film of precious metal (Ag, Au) which, in several cases, was combined with a Ni layer beneath. Five out of 10 items were not in compliance with the Ni Directive 94/27/EC having a total Ni content >
0.05%. In three cases the release of Ni concentrations was higher than the safe sensitizing limit given by the above mentioned Regulation (
i.e., <
0.5 μg/cm
2/week). The release of Cu and Zn was very variable among the different pieces (Cu: 0.134–30.9 μg/cm
2/week; Zn: 0.141–160 μg/cm
2/week); two objects released high amounts of Fe (358 and 586 μg/cm
2/week) and one released considerable Mn (21 μg/cm
2/week). Lead was released from 70% of the objects, while Ag, Al, Cd, Co, Cr and Sn from
ca. 30% of the items and concentrations of these elements were well below 0.5 μg/cm
2/week. Vanadium was released by only one item whereas Au, Ir, Pd, Pt and Rh were never leached.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Motivated mainly by future upgrades at high-luminosity LHC (HL-LHC) and detectors at future accelerators, most of the HEP R&D collaborations are focusing on the design of new particle detectors for ...operation under high particle flow. In the field of Micro-Pattern-Gaseous-Detectors, were designed the small-pad resistive Micromegas prototypes, to overcome the limitations of current resistive strip Micromegas chambers. In these new prototypes, pads with 1×3 mm 2 area replace the readout strips to reduce the occupancy. The spark protection resistive layer has been redesigned and optimized with different techniques to permit a safe behavior of the detector, at rates of the order of tens MHz/cm 2 over large surfaces without efficiency loss. The firstly-developed design exploits a pad-patterned embedded resistor layout made by screen-printing, while the most recent technique involves uniform sputtered DLC (Diamond Like Carbon structure) layers, where the charge evacuates through the several vias connected to the ground. Comparative studies have been conducted on the performance of the detectors with two resistive layouts, and between two DLC prototypes with different pitch of vias and surface resistivity. The results of the tests performed with high intensity X-rays and with high-energy charged particle beams will be presented.
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