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Journal of Radioanalytical and Nuclear Chemistry
Authors: Craig Aalseth, Erica Andreotti, Dirk Arnold, Joan-Albert Cabeza, Detlev Degering, Andrea Giuliani, Raquel de Orduña, Rodolfo Gurriaran, Mikael Hult, Martin Keillor, Matthias Laubenstein, Gilbert le Petit, Romul Margineanu, Murray Matthews, Harry Miley, Iolanda Osvath, Monica Pellicciari, Wolfango Plastino, Hardy Simgen, Marc Weber, and Robert Werzi

Abstract  

Aerosol samples collected on filter media were analyzed using HPGe detectors employing varying background-reduction techniques in order to experimentally evaluate the opportunity to apply ultra-low background measurement methods to samples collected, for instance, by the Comprehensive Test Ban Treaty International Monitoring System (IMS). In this way, realistic estimates of the impact of low-background methodology on the sensitivity obtained in systems such as the IMS were assessed. The current detectability requirement of stations in the IMS is 30 μBq/m3 of air for 140Ba, which would imply ~106 fissions per daily sample. Importantly, this is for a fresh aerosol filter. One week of decay reduces the intrinsic background from radon daughters in the sample allowing much higher sensitivity measurement of relevant isotopes, including 131I. An experiment was conducted in which decayed filter samples were measured at a variety of underground locations using Ultra-Low Background (ULB) gamma spectroscopy technology. The impacts of the decay and ULB are discussed.

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Acta Veterinaria Hungarica
Authors: Katalin Jánosi, László Stipkovits, Róbert Glávits, Tamás Molnár, László Makrai, Miklós Gyuranecz, János Varga, and László Fodor

Friis, N. F. (2000): Aerosol challenge of calves with Haemophilus somnus and Mycoplasma dispar . Vet. Microbiol. 72 , 229–239. Friis N. F. Aerosol challenge of calves

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Thermal analysis as an analytical tool has been applied to the study of suspended liquid and solid matter in air. The aerosol is heated in a glass pipe, and the light scattering coefficient is used for thein situ detection of aerosol. Results of thermal analysis of the Los Angeles smog, and of St. Louis aerosol on dry and humid days, are presented, all indicating distinctly different thermo-nephelograms. On polluted days in St. Louis, over 50% of the light scattering coefficient is lost at about 100‡, which indicates the presence of H2SO4.

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Abstract  

The equilibrium factor value (F) was measured in the NRPB radon chamber and the corresponding track density ratio (r = D/D 0) of bare (D) and diffusion (D 0) LR-115 nuclear track detectors was determined, as well as the regression equation F(r). Experiments with LR-115 nuclear track detectors and aerosol sources (burning candle and cigarette) were carried out in the Osijek University radon chamber and afterwards an empirical relationship between the equilibrium factor and aerosol concentration was derived. For the purpose of radon dose equivalent assessment, procedures for determining the unattached fraction of radon progeny were introduced using two nuclear track detectors.

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Abstract  

The aerosols adhering to one year old spruce needles are investigated as for the mass deposited and as for the chemical composition. The method for the isolation of the material is presented. 33 elements are determined by neutron activation analysis. Precision, accuracy, sampling error and variation over 14 sites at the interior of woods are discussed. Chemical composition is compared to local topsoil and to local aerosols collected on filters.

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Abstract  

57Fe Mössbauer spectroscopy has been employed to characterize the chemical composition of iron aerosols collected from three distinct groups of sites representing remote, urban and industrially active areas. The Mössbauer spectra clearly show this environmental difference. The fact that the spectra of the samples collected from the remote areas are quite similar to those of clay minerals corroborates the view that iron aerosols are soil derived. Similarly the predominant presence of -Fe2O3 and Fe3O4 in the close vicinity of industrial activities suggests that the Mössbauer spectroscopy can help identify the anthropogenic processes against the natural ones.

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Abstract  

Although Neutron Activation Analysis is usually not very common in aerosol physics, there are fields of application which seem to be rather successful. In general it is shown which properties activable aerosols should have, how they can be produced and how aerosol samples might be drawn. By use of special aerosol separators not only the mass-concentration but also the size-distribution of the aerosol can be determinated. Based on two studies, the utility of activable aerosols is demonstrated: Calibration and test of a simple discontinously working aerosol monitor for the off-gass system of isotope hoods; dynamic o radioactive ionized aerosols in a sealed room. Finally a general survey of further applications of activable aerosols is given.

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Abstract  

Four different artificial aerosol particles as well as one standard environmental aerosol particle (NIST SRM 1649a) were investigated. While the mass loss of the aerosol particles varies from 1.5 to 32% of the entire mass, only a small part of each volatile fraction consists of organic compounds. Due to the construction of the combined thermoanalytical system, only a small part of the evolved gases is used for the mass spectrometric investigation. This results in a restricted sensitivity which does not allow an identification of individual organic components. Additional investigations like thermal desorption GC-MS reveal up to 1600 individual components (SRM 1649a).

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Abstract  

Between 8th July 2002 and 18th June 2004, aerosol samples were collected in Azores. Their inorganic composition was obtained by neutron activation analysis in order to study the differences of aerosols in two atmospheric altitudes of the central north Atlantic: (1) PICO-NARE observatory (Lower Free Troposphere-LFT) at Pico mountain summit (38,470ºN, 28,404ºW, 2,225 m a.s.l.) in Pico Island, Azores, where air masses from the surrounding continents (Africa, Europe, Central and North America) pass through, carrying aerosols with anthropogenic (Sb, Br, Mo, U, Se and Tb) and/or natural emissions (Fe, Co, La, Na, Sm, Cr, Zn, Hf, K and Th); (2) TERCEIRA-NARE station (Marine Boundary Layer) at Serreta (38,69ºN, 27,36ºW, 50 m a.s.l.), in Terceira Island, Azores, where natural aerosols (I, Cl, Na, Br and other soil related elements) are predominant. However, a combined interpretation of the data points out to a co-existence of the anthropogenic elements Sb and Mo, eventually with similar origins as the ones passing Pico Mountain summit. Very high concentrations and enrichment factors for Sb, Mo and Br in LFT, higher than the ones found in other areas, confirm atmospheric long-range transport mainly from the west boundary of north Atlantic; this may indicate eventual accumulation and persistence of those elements in the area due to the presence of Azores high pressures or the Hadley cells effect. A significant correlation between Fe and Yb and the enrichment of rare earth elements (La, Sm, Tb and Yb) and Th in LFT aerosols, both reflect a mineral dust intrusions from north Africa (Sahara and Sahel region).

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Abstract  

Instrumental neutron activation analysis (INAA), flame atomic absorption spectrometry (FAAS), flame atomic emission spectrometry (FAES), graphite furnace atomic absorption spectrometry (GF-AAS), ion chromatography (IC) and visible spectrometry (VIS) were used to determine the composition of atmospheric aerosols, collected at a rural site in the Western Black Sea Coast of Turkey. A total of 354 daily aerosol samples were analyzed for 46 trace and major elements and ions. Sample preparation, quality control procedures, instrumental operating conditions for INAA and source apportionment work is presented.

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