Radioactivity concentrations and their radiological significance in sediments of the Tema Harbour (Greater Accra, Ghana)

Abstract Studies on environmental radioactivity in tropical Africa are scarce. Therefore, a baseline study of natural ( 238 U, 210 Pb, 226 Ra, 232 Th, 228 Ra, 228 Th, 40 K) and anthropogenic ( 137 Cs) radionuclides was carried out on Tema Harbour (Greater Accra, Ghana) surface sediments and on their radiological significance. Grab surface sediment samples were collected from 21 stations within the Tema Harbour and their radioactivity concentrations measured by gamma spectrometry. The mean sediment radioactivity concentrations (Bq kg −1 dw) were 34 for 238 U, 210 for 210 Pb, 14 for 226 Ra, 30 for 232 Th, 29 for 228 Ra, 31 for 228 Th, 320 for 40 K, and 1.5 for 137 Cs. Large 238 U/ 226 Ra disequilibria were observed in the harbour sediments and a complex dynamics of several mixed sources of sediments within the Tema Harbour can be inferred from the spatial variations in the radioactivity concentrations. The estimated total absorbed dose rate in air ( D ), radium equivalent activity (Ra eq ), external hazard index ( H ex ), annual gonadal dose equivalent (AGDE) and annual effective dose equivalent (AEDE) indicated no significant radiological risks from the sediment radioactivity concentrations. Application of the Environmental Risk from Ionising Contaminants Assessment and Management tool (ERICA) confirmed that the potential dose rates to biota from the sediment radioactivity concentrations are unlikely to pose appreciable ecological risks. The radioactivity levels are compared with levels reported in sediments from other coastal areas of the world

Settling fluxes and sediment accumulation rates by the combined use of sediment traps and sediment cores in Tema Harbour (Ghana)

Settling fluxes and sediment accumulation rates in coastal Tema Harbour (Ghana) were investigated by the combined analyses of results in sediment traps and sediment cores. Sediment traps were deployed at 5 stations within the Tema Harbour at two sampling depths and were retrieved every two weeks till the end of 12 weeks to estimate the Settling Fluxes (SFs). Four sediment cores from the harbour were analysed for their radioactivity (7Be, 234Th, 210Pb, 212Pb, 226Ra, 40K and 137Cs) profiles to quantify Sediment Accumulation Rates (SARs). The sediment cores exhibited variable bulk density profiles, indicating highly dynamic and non-steady sedimentation conditions. 7Be-derived gross-estimates of very recent SARs using the constant flux-constant sedimentation (CF-CS) model were in the range of 2.5–9.0 g·cm− 2·y− 1. These values were much lower than the estimated average SFs (15.2–53.8 g·cm− 2·y− 1), indicating sediment resuspension plays an important role. On a decadal time scale, conventional 210Pb sediment dating models did not allow any estimation of SARs in the Tema Harbour. Thus, the 210Pb-based TERESA model was applied to depict a reliable scenario for sedimentation with time-averaged SARs in the range of 1.4–3.0 g·cm− 2·y− 1 and fluxes of matter contributed by the marine inflow and local sources. Sediment accretion rates of 1.7–3 cm·y− 1 were also inferred, which may pose a moderate problem of sustainability for the Tema Harbour. This study reveals how the geochemical behaviour of different radionuclides with Gamma spectrometry in the marine environment can be used to obtain reliable information on the complex dynamics of Suspended Particulate Matter (SPM), even in a very disturbed and anthropic environment as a coastal harbour area where (1) conventional 210Pb-based dating methods fail and (2) the use of sediment traps and 234Th and 7Be profiles in sediment cores show serious constraints.University of Ghana UGFD/7/2012-2013/00

Rapporto tecnico sulle attività di campionamento della “Campagna Oceanografica CISAS_2” Crotone 07-12 dicembre 2017

Le attività di campionamento ed acquisizione dati svolte durante la campagna CISAS_2 si inseriscono in seno al progetto “Centro internazionale di studi avanzati su ambiente ed impatti su ecosistema e salute umana (CISAS)” del CNR. L’obiettivo principale del progetto CISAS è la comprensione dei processi e dei meccanismi di trasferimento di alcuni contaminanti convenzionali (metalli pesanti, POPs, radionuclidi, ecc.) e di alcuni contaminanti emergenti (PDBE, composti farmaceutici di nuova generazione, ecc.) dall’ambiente inteso come l’insieme di atmosfera-suoli-acque sotterranee-matrici marine (acque e sedimento) all’ecosistema e all’uomo. Le aree di indagine del progetto sono i Siti di Interesse Nazionale (SIN) di Priolo, Milazzo-Pace del Mela e Crotone che, per specificità e modalità di impatto antropogenico sull’ambiente, l’ecosistema e la salute umana, coprono un ampio spettro di tipologie di interesse. La campagna oceanografica CISAS_ 2 è stata dedicata alla caratterizzazione ambientale del SIN di Crotone, nonché all’identificazione delle sorgenti dei contaminanti la cui distribuzione si ritiene di interesse (per i valori di concentrazione riscontrati nelle diverse matrici ambientali e per livello di tossicità associata agli effetti degli stessi sulla salute dell’ecosistema e dell’uomo) e i pathways di deposizione nelle aree di interesse

Cold atoms in space: community workshop summary and proposed road-map

We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies.publishedVersio

Cold atoms in space: community workshop summary and proposed road-map

We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies

Terrestrial Very-Long-Baseline Atom Interferometry:Workshop Summary

This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more km-scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions

Cold atoms in space: community workshop summary and proposed road-map

We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies

Composizione e trasporto delle sabbie delle coste marine italiane

This work focuses on the physical structure and processes of the Italian coasts and takes advantage of the original joint research recently carried out by the Department of Earth Sciences of the University of Parma and the ENEA Marine Research Centre of Santa Teresa. On such base, several specific databases (e.g. Coastal Cells) were created and the available data (e.g. Morpho-sedimentological types) were adapted to the requirements of the research. This was accompanied by the production of a homogenous set of petrographic and granulometric data on beach sands of the Italian coasts. GIS technologies (geodatabase ©ESRI, ArcMap) were applied through extensively. These original data are complementary to the relevant literature identifying coastal petrographic provinces on numerous coastal tracts. The sampling of beach sands was then planned on the remaining part of the Italian coastline. A total of 137 samples were collected; 135 of them were analysed for granulometry and thin-section optical microscopy. These original analyses, integrated to the available data on coastal petrographic provinces, provide a quantitative assessment of the petrophysical characteristics of the Italian native beach sands

DataSheet1_Helium isotopes in Plinian and inter-Plinian volcanic products of Vesuvius, Italy.pdf

We investigated helium isotopes on gas extracted by crushing from melt and fluid inclusions in minerals from Plinian and inter-Plinian tephra and lavas of Vesuvius, Italy. Erupted products of different ages were considered, from Avellino eruption (1995 BCE) to the last eruption of 1944, with special focus on the 79 AD Plinian eruption. He/He 4 3 ratios between 1.5 and 2.7 RA were measured, with the highest values associated with rocks representative of the roof and the walls of the magma chambers (cumulates). Lowest values occurred in sanidines representative of magma-skarn interfaces. Noteworthy, the highest measured values of the 79 AD pumices were comparable with both lavas and tephra emitted from flank vents and under open-conduit conditions during the Medieval Period and Present Period of Vesuvius activity, and present-day fumarolic discharges. He 3/He 4 values are buffered within an extended, deep-seated reservoir at about 10 km filled with magma rising from the mantle. A fact that might potentially limit the accuracy of future eruption forecasting through monitoring of He/He 4 3 changes in Vesuvius fumaroles. Ageing and interaction with crustal rocks emerged as possible mechanisms that lowered the He/He 4 3 ratio of the melt during its intra-crustal magma chambers stay, with highest values associated with more dynamic conditions.</p