1,721,026 research outputs found
Gross Alpha and Beta Radioactivity Evaluation in Drinking Water: Results from the Calabria Region, Southern Italy
No full textIn this article, authors report experimental results obtained for the assessment of gross alpha and beta radioactivity in drinking waters, coming from the Calabria region, southern Italy. The measurements, performed with the Perkin-Elmer Tricarb 4910 TR Liquid Scintillation Counter (LSC) setup, were compared with reference values derived from Italian regulations (the Italian Legislative Decree n. 28/2016) to evaluate the existence of possible health risks for the population due to the ingestion of gross alpha and beta radioactivity in the analyzed drinking waters. Experimental results underline that both specific activities in the investigated drinking waters varies widely. In particular, for gross alpha, the activity concentration ranges from a minimum value lower than the LSC minimum detectable activity (MDA), 0.04 Bq L−1, for the site IDs 13, 28, 34, 35, 38, 44, 53, to a maximum of (0.16 ± 0.03) Bq L−1 for the site ID 22; for gross beta, the specific activity varies from a minimum value lower than the LSC MDA, 0.20 Bq L−1, for all the sampling sites except for the site IDs 5, 6, 9, 13, 15, 18, 19, 25, 27, 29, 33, 34, 40, to a maximum of (0.34 ± 0.07) Bq L−1 for the site ID 15. Obtained results represent a main reference for the investigated area, and they are useful to determine the associated radiological health risks for the population
Monothalamous soft-shelled foraminiferal image dataset from the Kveithola Trough (NW Barents Sea)
Full text linkWe present an image dataset of monothalamous soft-shelled Foraminifera (Monothalamea, [1]), an important component of benthic foraminiferal assemblage in sediment cores collected during two oceanographic expeditions that contributed to the MSM30-CORIBAR project (Ice dynamics and meltwater deposits: coring in the Kveithola trough, NW Barents Sea). 9 subsamples of sediment cores were collected during different years (2013-2016) in the Kveithola Trough, a glacially carved system in the NW Barents Sea. Cores were retrieved using a multi-corer (MUC) and a giant box-corer (GBC) and the subcores for foraminiferal analyses were obtained using Plexiglas tubes inserted manually into the cores. These subcores were sliced at 0.5 cm intervals down to 2 cm sediment depth and then every 1 cm down to 10 cm. Two staining methods, Cell Tracker Green (CTG) and Rose Bengal (RB), were used to distinguish between living and dead individuals. Then, the fixed sediment samples were sieved through 63 and 150 μm mesh screens and preserved in 10 % borax-buffered formalin. Six species and 37 undescribed morphotypes were recognized and included in this image dataset. Relatively few species of soft-shelled, monothalamous foraminifera have been described compared to a much larger number of undescribed morphotypes recognised from across the marine realm. Few researchers study with their taxonomy because of the time and difficulties that morphological identification involves. In addition, because "soft", delicate monothalamids rarely fossilize, they are generally overlooked by micropaleontologists. However, they are abundant and diverse and represent an important faunal component of marine as well as freshwater ecosystems. Further information about these frequently overlooked protists will help to address important knowledge gaps and enhance our ability to manage and conserve the planet's resources responsibly. In particular, our image dataset highlights the importance of monothalamous soft-shelled foraminifera in this peculiar Arctic environment and contributes to the first species/morphotype checklist for the area. We hope it will serve to fill gaps in knowledge regarding the ecology and biodiversity of benthic foraminifera, helping users to identify monothalamids species and morphotypes in Arctic waters and beyond. This data article is associated with the research papers: "Benthic foraminiferal assemblages and environmental drivers along the Kveithola Trough (NW Barents Sea)" by [2]
Physical characterization of pulsed laser deposition of diamond-like nanostructures
No full textDiamond-like carbon (DLC) films can be produced by Pulsed Laser Deposition (PLD) technique in vacuum. Energetic laser pulses, with intensity of the order of 1010W/cm2, can be employed to generate hot carbon plasmas from glassy carbon ablation. Particles ejected from plasma can be deposited and/or ion implanted on different substrates. Energetic particles diffuse on the substrate surface and may generate nucleation and nanostructures. In the present work a Nd:Yag laser radiation, 532 nm wavelength, 9 ns pulse duration and 30 Hz repetition rate, was employed to grow thin DLC films on SiO2 substrates, placed at different distances and angles from the target. The PLD-generated plasma can be controlled "on line" by mass quadrupole spectrometry and time-of-flight techniques, in order to evaluate the atomic and molecular kinetic energy distributions. "Off line" investigations were performed on the deposited films by using scanning electron microscopy (SEM), atomic force microscopy (AFM), infrared-absorption spectroscopy (FTIR) and Raman spectroscopy. Nanostructures with cubic shape and 300 nm average size growth on SiO2 surface are investigated and discussed. © Institute of Physics, Academy of Sciences of Czech Republic 2006
Effect of filler amount in the welding of plastics induced by Visible Laser irradiation
No full textLaser welding of plastics is based on the local energy release of the laser beam to the polymer joint. The process, known as Through 'IYansmission Visible Laser Welding (TTVLW) technique, involves a ns pulsed laser beam of visible light, transmitted by the transparent polymeric part and absorbed at the surface of the other polymeric part. It promotes photo-thermal, photo-chemical and ion implantation processes locally, in the small regions of the irradiated polymer which enables the parts to be welded rapidly. In this work, the TTVLW is applied in order to induce the welding between different polyethylene films, pure and filled with carbon or iron nano-compounds. The mechanical resistance and the physical features of the welded joints are investigated by physical and static mechanical tests. Results proved the effectiveness of the TTVLW technique since high resistance joints are obtained. The joints are investigated as a function of some laser irradiation parameters and polymeric materials properties
Radioactivity measurements in water: An overview of the actual technologies
No full textAmong the most significant matrices in the field of environmental radioactivity, water is certainly included, being subject to monitoring and controls to safeguard the environment from pos-sible anthropogenic contamination. The presence of radionuclides in water also constitutes a health risk to human, because its consumption increases the likelihood of incurring cancer. In authors’ laboratory, different experimental techniques were employed to measure radioactivity content of surface and drinking water, according to the Italian Legislation and to the Italian Institute for the Environmental Protection and Research (ISPRA) guidelines. Gamma spectrometry was employed to quantify the specific activity of gamma-emitters anthropogenic contaminants and natural radionuclides; liquid scintillation counting (LSC), to measure the activity concentration of triti-um, radon and gross alpha and beta; total alpha/beta counting, with the thick source method, to de-tect about gross alpha and beta specific activity; emanometry, to estimate gas radon activity concen-tration
A new Arctic seepage site? Preliminary evidence from benthic community.
Full text linkThe Kveithola Trough is an abrupt and narrow sedimentary system located in the NW Barents Sea. The hydrographic,
bio-geochemical conditions and the possible existence of gas seepage activity of the area have been
investigated during the Eurofleets 2- BURSTER cruise, conducted on board the German icebreaker RV Polarstern.
The aim of our work is to characterize the benthic biota and more specifically the macrofaunal community
structure coupled to the study of benthic foraminiferal meiofauna.
Preliminary qualitative results revealed that in the inner Kveithola Trough, the macrofaunal community is
composed by abundant black worm tubes (Chaetopteridae worms and Siboglinidae-like taxa) with presence of
Thyasiridae bivalve species. The occurrence of these macrofaunal taxa is usually associated to oxygen-reduced
environments, hydrothermal vents and cold seeps. The living benthic foraminiferal assemblage in the same
stations is characterized by the presence of typically oxygen-depleted environmental taxa including the calcareous
species Nonionellina labradorica and Globobulimina spp.. Conversely, in the outer Kveithola trough, both benthic
macrofauna and foraminiferal meiofauna assemblages are characterized by less opportunistic taxa with a higher
biodiversity suggesting very distinct oceanographic sea bottom conditions.
The organic matter richness plays a large role in the Kveithola Trough environmental setting and may bring
anoxic conditions that could affect the biota of the area. In fact, the benthic community structure of this area
inhabits suboxic, anoxic and organic-enriched sediments and disturbed environments, forming assemblages with
low diversity and high abundances of a few tolerant and/or specialized species.
This preliminary finding could be consistent with other studies examining benthic community structure around
Svalbard and in particular cold seep and vents habitats where faunal characteristics are patchy, suggesting
small-scale heterogeneity in the environment surrounding cold seeps. For said reasons we envisage the presence
of a new Arctic seepage site having a strong local impact on the benthic system
Multi-element analysis and geographical origin classification of italian (Calabrian) wines
No full textBackground and Objective: In this article, a comprehensive study was carried out for food authenticity evaluation through chemometric analyses, correlating botanical and geographical origins with food chemical composition. Methods: A total of eighteen Calabrian red, rose and white wines were analyzed through Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results: The mineral concentrations, determined by ICP-MS in the investigated wine samples, followed the subsequent order: K > P > Mg > Na > Ca > Fe > Cu > Zn > Mn > V. The 2D Scatterplot and loading plot (Principal Component Analysis) showed that all red, rose and white wine samples from “Cirò” DOP area were grouped in the fourth, second and third quadrant, respectively, clearly separated from each other. Samples from “Cirò” red showed positive PC1 and were characterized by higher K, Fe, Mn, Na, V and Zn concentrations. Moreover, the points corresponding to two red wines from the “Terre di Cosenza” DOP area fall into the first quadrant; those corresponding to two rose wines from the “Donnici” and “Sant’Anna di Isola di Capo Rizzuto” DOP areas fall into the third and fourth quadrants, respectively; the point corresponding to a white wine from the “Donnici” DOP area falls into the second quadrant. Conclusion: Experimental results demonstrated that it is possible to strictly relate, through the PCA, wines to their geographical and botanical provenance, thus becoming a useful tool for evaluating the product authenticity and guaranteeing it to the consumers
Radon radioactivity in groundwater from the Calabria region, south of Italy
No full textIn the present study the radon radioactivity in selected groundwater (boreholes and wells) from the Calabria region, south of Italy, was investigated. Water samples were analyzed by gamma spectrometry and by RAD7 +RADH2Osetup to determine the 222Rn activity concentration. Obtained values were used with the ingested dose conversion factor for 222Rn to estimate the annual effective dose for adult members of public due to consumption of the groundwater. The estimated average value was (88± 5) μSv/y. It was compared with the estimated average annual effective dose due to ingestion of groundwater by the WHO (100 μSv/y) and that due to ingestion of food and water (290 μSv/y) by the UNSCEAR (2000). Results show that the presence of radon may not pose any radiological health hazard to the public due to the consumption of groundwater in the investigated region. 2016 IOP Publishing Ltd and Sissa Medialab srl
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