Search results for " sampler."
showing 10 items of 13 documents
RADIONUCLIDE CONCENTRATIONS IN AIR PARTICULATE AT PALERMO (ITALY) FOLLOWING FUKUSHIMA ACCIDENT
2012
Following the Fukushima accident, a series of samplings were carried out with a daily frequency to detect the arrival of radioactive contamination in air at Palermo (Italy) and to follow its evolution during the time. Air particulate collection was performed by suction of atmospheric air through cellulose filter paper by means of a high-volume air sampler (∼15 000 m(3) d(-1)). Spectrometric analysis of the filters highlights the presence of (131)I, (134)Cs, (137)Cs and, only for a few samples, traces of (132)Te-(132)I and (136)Cs. Maximum airborne concentrations were 883 μBq m(-3) for (131)I (only particulate), 81 μBq m(-3) for (137)Cs and 70 μBq m(-3) for (134)Cs. From a dose to population…
Bayesian Inference for the Exponential Power Function Parameters
2008
This paper addresses the problem of obtaining the marginal posterior distributions, via Gibbs Sampler, for the parameters of the well-known generalized error distribution called Exponential Power Function (E.P.F.). This density represents a family of unimodal symmetric distributions with shapes varying from leptokurtic to platikurtic.
Polydimethylsiloxane (silicone rubber) brooch as a personal passive air sampler for semi-volatile organic compounds
2018
Exposure assessments conducted using a personal sampler include the contribution of human activities to exposure that is neglected when using a stationary air sampler. This study evaluated the uptake characteristics and application of the polydimethylsiloxane (PDMS or silicone rubber) brooch as a personal passive air sampler (PPAS) for measuring concentrations of two groups of semi-volatile organic compounds (SVOCs), namely phthalates and organophosphate esters (OPEs), indoors in proximity to the breathing zone. Uptake rates of the PDMS brooch were calibrated against a personal low volume active air sampler (PLV-AAS) co-deployed on each of five study participants working in offices for 8 hs…
The miniaturised emission chamber system and home-made passive flux sampler studies of monoaromatic hydrocarbons emissions from selected commercially…
2017
Abstract The estimation of the emission rate of organic compounds released from various types of indoor materials can be performed using stationary environmental test chambers (ETC) classified as ex-situ methods or small-scale portable analytical devices based on the use of passive technique at the stage of analytes sampling from the gaseous phase (in-situ methods). The paper presents results of emissions of selected organic compounds from the monoaromatic hydrocarbons group (benzene, toluene, ethylbenzene, p,m-xylene and styrene) emitted from the surfaces of various types of commercially-available floor coverings and the underlay made of polyurethane foam which might be installed indoors u…
The Impact of Candle Burning During All Saints’ Day Ceremonies on Ambient Alkyl-Substituted Benzene Concentrations
2013
Research findings concerning benzene, toluene, ethylobenzene, meta-, para- and ortho-xylene as well as styrene (BTEXS) emission at public cemeteries during All Saints’ Day are presented here. Tests were carried out at town-located cemeteries in Opole and Grodków (southern Poland) and, as a benchmark, at the centres of those same towns. The purpose of the study was to estimate BTEXS emissions caused by the candle burning and, equally important to examine, whether emissions generated by the tested sources were similar to the BTEXS emissions generated by road transport. During the festive period, significant increases in benzene concentrations, by 200 % and 144 %, were noted at the cemeteries …
Bioavailability of pharmaceuticals in waters close to wastewater treatment plants: Use of fish bile for exposure assessment
2012
Pharmaceuticals are ubiquitous in surface waters as a consequence of discharges from municipal wastewater treatment plants. However, few studies have assessed the bioavailability of pharmaceuticals to fish in natural waters. In the present study, passive samplers and rainbow trout were experimentally deployed next to three municipal wastewater treatment plants in Finland to evaluate the degree of animal exposure. Pharmaceuticals from several therapeutic classes (in total 15) were analyzed by liquid chromatography-tandem mass spectrometry in extracts of passive samplers and in bile and blood plasma of rainbow trout held at polluted sites for 10 d. Each approach indicated the highest exposure…
Assessing persistent organic pollutants (POPS) in the sicily island atmosphere, mediterranean, using PUF disk passive air samplers
2016
In this study, PUF disk passive air samplers were deployed at eight sites, during two sampling periods, on the Island of Sicily in the Mediterranean basin. Samples were screened for a number of persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs) (n = 28 congeners), organochlorine pesticides (OCPs) (n = 16 compounds), and polybrominated biphenyl ethers (PBDEs n = 28) using GC-MS. PCB concentrations in air ranged ~10-300 pg m-3. The PCB pattern was dominated by lower to middle molecular weight PCBs (Cl3-5) and PCB-28 and PCB-52 were the most abundant congeners. α- and γ-Hexachlorocyclohexanes (HCHs) concentrations in air were relatively high ~420 ± 320 (50-1000) an…
Hydrogen sulfide measurements in air by passive/diffusive samplers and high-frequency analyzer: A critical comparison
2016
In this study, hydrogen sulfide (H2S) measurements in air carried out using (a) passive/diffusive samplers (Radiello® traps) and (b) a high-frequency (60 s) real-time analyzer (Thermo® 450i) were compared in order to evaluate advantages and limitations of the two techniques. Four different sites in urban environments (Florence, Italy) and two volcanic areas characterized by intense degassing of H2S-rich fluids (Campi Flegrei and Vulcano Island, Italy) were selected for such measurements. The concentrations of H2S generally varied over 5 orders of magnitude (from 101e103 mg/m3), the H2S values measured with the Radiello® traps (H2SR) being significantly higher than the average values measure…
Un nuovo campionatore per la misura della perdita di suolo in parcelle attrezzate
2012
Le misure di perdita di suolo in parcelle attrezzate necessitano la conoscenza del peso del materiale eroso intercettato nella sezione terminale delle parcelle. Nell’area sperimentale di Sparacia attrezzata per la misura della perdita di suolo i deflussi torbidi prodotti in seguito ad un evento erosivo vengono convogliati mediante una grondaia posta a valle di ciascuna parcella all’interno di vasche di accumulo. Per misurare la frazione di materiale solido presente nel volume della sospensione raccolto in dette vasche, si propone l’utilizzo di un nuovo campionatore appositamente predisposto. Esso consiste in un cilindro di ottone, di noto diametro, dotato nella sezione terminale di una valv…
On implementation of the Gibbs sampler for estimating the accuracy of multiple diagnostic tests
2010
Implementation of the Gibbs sampler for estimating the accuracy of multiple binary diagnostic tests in one population has been investigated. This method, proposed by Joseph, Gyorkos and Coupal, makes use of a Bayesian approach and is used in the absence of a gold standard to estimate the prevalence, the sensitivity and specificity of medical diagnostic tests. The expressions that allow this method to be implemented for an arbitrary number of tests are given. By using the convergence diagnostics procedure of Raftery and Lewis, the relation between the number of iterations of Gibbs sampling and the precision of the estimated quantiles of the posterior distributions is derived. An example conc…