Oxidative potential associated with urban aerosol deposited into the respiratory system and relevant elemental and ionic fraction contributions

Size-segregated aerosol measurements were carried out at an urban and at an industrial site. Soluble and insoluble fractions of elements and inorganic ions were determined. Oxidative potential (OP) was assessed on the soluble fraction of Particulate Matter (PM) by ascorbic acid (AA), dichlorofluorescein (DCFH) and dithiothreitol (DTT) assays. Size resolved elemental, ion and OP doses in the head (H), tracheobronchial (TB) and alveolar (Al) regions were estimated using the Multiple-Path Particle Dosimetry (MPPD) model. The total aerosol respiratory doses due to brake and soil resuspension emissions were higher at the urban than at the industrial site. On the contrary, the doses of anthropic combustion tracers were generally higher at the industrial site. In general, the insoluble fraction was more abundantly distributed in the coarse than in the fine mode and vice versa for the soluble fraction. Consequently, for the latter, the percent of the total respiratory dose deposited in TB and Al regions increased. Oxidative potential assay (OPAA) doses were distributed in the coarse region; therefore, their major contribution was in the H region. The contribution in the TB and Al regions increased for OPDTT and OPDCFH

Temperature and pressure gas geoindicators at the Solfatara fumaroles (Campi Flegrei)

Long time series of fluid pressure and temperature within a hydrothermal system feeding the Solfatara fumaroles are investigated here, on the basis of the chemical equilibria within the CO2-H2O-H2-CO gas system. The Pisciarelli fumarole external to Solfatara crater shows an annual cycle of CO contents that indicates the occurrence of shallow secondary processes that mask the deep signals. In contrast, the Bocca Grande and Bocca Nova fumaroles located inside Solfatara crater do not show evidence of secondary processes, and their compositional variations are linked to the temperature–pressure changes within the hydrothermal system. The agreement between geochemical signals and the ground movements of the area (bradyseismic phenomena) suggests a direct relationship between the pressurization process and the ground uplift. Since 2007, the gas geoindicators have indicated pressurization of the system, which is most probably caused by the arrival of deep gases with high CO2 contents in the shallow parts of the hydrothermal system. This pressurization process causes critical conditions in the hydrothermal system, as highlighted by the increase in the fumarole temperature, the opening of new vents, and the localized seismic activity. If the pressurization process continues with time, it is not possible to rule out the occurrence of phreatic explosions

From Megabits to CPU Ticks: Enriching a Demand Trace in the Age of MEC

All the content consumed by mobile users, be it a web page or a live stream, undergoes some processing along the way; as an example, web pages and videos are transcoded to fit each device’s screen. The recent multi-access edge computing (MEC) paradigm envisions performing such processing within the cellular network, as opposed to resorting to a cloud server on the Internet. Designing a MEC network, i.e., placing and dimensioning the computational facilities therein, requires information on how much computational power is required to produce the contents needed by the users. However, real-world demand traces only contain information on how much data is downloaded. In this paper, we demonstrate how to enrich demand traces with information about the computational power needed to process the different types of content, and we show the substantial benefit that can be obtained from using such enriched traces for the design of MEC-based networks.This work is supported by the European Commission through the H2020 projects 5G-TRANSFORMER (Project ID 761536) and 5G-EVE (Project ID 815074)

Improving monitoring techniques by exploiting TerraSAR-X data: an application to Campi Flegrei (Naples, Italy)

Geodetic monitoring of the Neapolitan Volcanic District, including the Campi Flegrei caldera on the west of the city of Naples (Italy), is carried out via an integration between ground based networks and space-borne DInSAR techniques, exploiting the SAR sensors onboard ERS1-2 and ENVISAT satellites. This allowed, for instance, to follow the time evolution of the small uplift events which took place in 2000 and 2005-2006. Unfortunately, the use of the ENVISAT C-band could result sometimes in no information when dealing with very low deformation rates, as in the 2005-2006 case, when only continuous ground stations were able to detect the very beginning of the uplift event. To overcome this problem, from December 2009 we decided to use an high resolution SAR sensor operating in the X band, i.e. TerraSAR-X from DLR. TerraSAR-X High Resolution Spotlight scenes covering the main part of the Campi Flegrei caldera and centred on the Solfatara crater were used for a DInSAR analysis, using the GENESIS DLR’s software. The first two scenes (Dec. 15 and 26) were acquired with a temporal baseline of only one repetition cycle (11 days) and formed an interferogram with a very small perpendicular baseline (16.5 m). Apart from some minor atmospheric effects, the interferogram shows a small but clear deformation signal in the Pisciarelli area, close to the east side of the Solfatara crater. The ellipse shaped uplift area extends approximately 30 meters in E-W and 20 meters in N-S directions and the maximum deformation is up to 10 mm in the centre of the uplifted area. The availability of a new scene (06/01/2010) allowed three possible combinations. The deformation event highlighted by this analysis is consistent with geochemical observations carried out in Pisciarelli by INGV-OV. Pisciarelli area is seat of a fumarolic field systematically monitored in the frame of the volcanic surveillance of the Campi Flegrei caldera. Two field surveys highlighted that, during the period of SAR images acquisition, a new and strong fumarolic vent appeared in the centre of the uplifted area. In fact the vent, firstly observed on Dec. 21, was absent on Dec. 16. The two independent observations, field surveys and SAR data, suggest that the opening of the fumarolic vent was preceded by the pressurization of a small part of the fumarolic field highlighted by the documented uplift. The correlation between the dynamics of the fumarolic field and the deformation signal is confirmed by the fact that in the 26/12/2009-06/01/2010 interferogram the deformation signal is no more detectable. Finally, this case proves the high potentiality of TerraSAR-X High Resolution Spotlight data in monitoring volcanic activity with a resolution suitable for detecting also minor, but possibly dangerous, changes of the systems, as it could be in the early recognition of the signals generated by impending phreatic eruptions. TerraSAR-X High Resolution Spotlight acquisitions will continue every cycle and PS-InSAR and SBAS algorithms will be applied to carefully monitor any further changes in the activity of the Campi Flegrei volcanic system

Long time-series of chemical and isotopic compositions of Vesuvius fumaroles: evidence for deep and shallow processes

Long time-series of chemical and isotopic compositions of Vesuvius fumaroles were acquired in the framework of the volcanic surveillance in the 1998-2010 period. These allow the identification of processes that occur at shallow levels in the hydrothermal system, and variations that are induced by deep changes in volcanic activity. Partial condensation processes of fumarolic water under near-discharge conditions can explain the annual 18O and deuterium variabilities that are observed at Vesuvius fumaroles. Significant variations in the chemical compositions of fumaroles occurred over the 1999-2002 period, which accompanied the seismic crisis of autumn 1999, when Vesuvius was affected by the most energetic earthquakes of its last quiescence period. A continuous increase in the relative concentrations of CO2 and He and a general decrease in the CH4 concentrations are interpreted as the consequence of an increment in the relative amount of magmatic fluids in the hydrothermal system. Gas equilibria support this hypothesis, showing a PCO2 peak that culminated in 2002, increasing from values of ~40 bar in 1998 to ~55-60 bar in 2001- 2002. We propose that the seismic crisis of 1999 marked the arrival of the magmatic fluids into the hydrothermal system, which caused the observed geochemical variations that started in 1999 and culminated in 2002

New insights into Mt. Vesuvius hydrothermal system and its dynamic based on a critical review of seismic tomography and geochemical features

The seismic velocity and attenuation tomography images, calculated inverting respectively P-wave travel times and amplitude spectra of local VT quakes at Mt. Vesuvius have been reviewed and graphically represented using a new software recently developed using Mathematica8TM. The 3-D plots of the interpolated velocity and attenuation fields obtained through this software evidence low-velocity volumes associated with high attenuation anomalies in the depth range from about 1 km to 3 km below the sea level. The heterogeneity in the distribution of the velocity and attenuation values increases in the volume centred around the crater axis and laterally extended about 4 km, where the geochemical interpretation of the data from fumarole emissions reveals the presence of a hydrothermal system with temperatures as high as 400-450°C roughly in the same depth range (1.5 km to 4 km). The zone where the hydrothermal system is space-confined possibly hosted the residual magma erupted by Mt. Vesuvius during the recent eruptions, and is the site where most of the seismic energy release has occurred since the last 1944 eruption

Long Time Series Of Fumarolic Compositions At Volcanoes: The Key To Understand The Activity Of Quiescent Volcanoes

Long time series of fumarolic chemical and isotopic compositions at Campi Flegrei, Vulcano, Panarea, Nisyros and Mammoth volcanoes highlight the occurrence of mixing processes among magmatic and hydrothermal fluids. At Campi Flegrei temperatures of about 360°C of the hydrothermal system are inferred by chemical and isotopic geoindicators. These high temperatures are representative of a deep zone where magmatic gases mix with hydrothermal liquids forming the gas plume feeding the fumaroles. Similar mixing processes between magmatic fluids and a hydrothermal component of marine origin have been recognized at Vulcano high temperature fumaroles. In both the system a typical ‘andesitic’ water type composition and high CO2 contents characterizes the magmatic component. Our hypothesis is that pulsing injections of these CO2- rich magmatic fluids at the bottom of the hydrothermal systems trigger the bradyseismic crises, periodically affecting Campi Flegrei, and the periodical volcanic unrest periods of Vulcano. At Campi Flegrei a strong increase of the fraction of the magmatic component marked the bradyseismic crisis (seismicity and ground uplift) of 1982-84 and four minor episodes occurred in 1989, 1994 and 2000 and 2006. Increases of the magmatic component in the fumaroles of Vulcano were recorded in 1979-1981, 1985, 1988, 1996, 2004 and 2005 concurrently with anomalous seismic activity. Physicalnumerical simulations of the injection of hot, CO2 rich fluids at the base of a hydrothermal system, asses the physical feasibility the process. Ground deformations, gravitational anomalies and seismic crisis can be well explained by the complex fluid dynamic processes caused by magma degassing episodes. Sporadic data on the fumaroles of other volcanoes, for example Panarea, Nisyros (Greece), Mammoth (California), suggest that magma degassing episodes frequently occur in dormant volcanoes causing volcanic unrest processes not necessarily linked to magma movement but rather to pulsating degassing processes from deep pressurized, possibly stationary, magma bodies

Performance Analysis of C-V2I-Based Automotive Collision Avoidance

One of the key applications envisioned for C-V2I (Cellular Vehicle-to-Infrastructure) networks pertains to safety on the road. Thanks to the exchange of Cooperative Awareness Messages (CAMs), vehicles and other road users (e.g., pedestrians) can advertise their position, heading and speed and sophisticated algorithms can detect potentially dangerous situations leading to a crash. In this paper, we focus on the safety application for automotive collision avoidance at intersections, and study the effectiveness of its deployment in a C-V2I-based infrastructure. In our study, we also account for the location of the server running the application as a factor in the system design. Our simulation-based results, derived in real-world scenarios, provide indication on the reliability of algorithms for car-to-car and car-to-pedestrian collision avoidance, both when a human driver is considered and when automated vehicles (with faster reaction times) populate the streets.This work was partially supported by TIM through the research contract “Multi-access Edge Computing”, and by the European Commission through the H2020 5GTRANSFORMER project (Project ID 761536

Carbon dixide emission in Italy: Shallow crustal sources or subduction related fluid recycling?

Anomalous non-volcanic CO2 release in central and southern Italy has been highlighted by ten years of detailed investigations on Earth degassing processes. Two regional degassing structures are located in the Tyrrhenian sector where more then 200 emissions of CO2 are located and has been recently included in the first web based catalogue of degassing sites (http://googas.ov.ingv.it). The total amount of CO2 released by the two structures were evaluated to be > 2×1011 mol a-1 ( >10% of the estimated global volcanic CO2 emission). The anomalous flux of CO2 suddenly disappears in the Apennine in correspondence of a narrow band where most of the Italian seismicity concentrates. Here, at depth, the gas accumulates in crustal traps generating CO2 overpressurised reservoirs. These overpressured structures are, in our opinion, one of the main cause of Apennine earthquake activation processes. The results of these investigations suggested that Earth degassing in Italy may have an active primary role in the geodynamics of the region. What is the origin of gas? The large extension of the degassing structures and petrologic data suggested that the main source of gas is a mantle metasomatised by the fluids produced in the subdacted slabs. However, has been also hypothesised the presence of localised crustal source of the gas. This matter will be discussed on the base of unpublished isotopic data of the main gas emissions

Geochemical and biochemical evidence of lake overturn and fish-kill at Lake Averno, Italy.

Lake Averno is situated in the homonymous crater in the northwestern sector of the Campi Flegrei active volcanic system in Campania region, Italy. In February 2005 a fish kill event was observed in the lake, prompting a geochemical survey to ascertain the possible cause. In February 2005 a geochemical survey revealed that the lake water was unstratified chemically and isotopically, presumable, as a result of lake overturn. This fish-kill phenomenon was recorded at least two other times in the past. In contrast to the February 2005 results, data collected in October 2005, shows the Lake Averno to be stratified, with an oxic epilimnion (surface to 6 m) and an anoxic hypolimnion (6 m to lake bottom at about 33 m). Chemical and isotopic composition of Lake Averno waters suggests an origin by mixing of shallow waters with a Na-Cl hydrothermal component coupled with an active evaporation process. The isotopic composition of Dissolved Inorganic Carbon, as well as the composition of the non-reactive dissolved gas species again supports the occurrence of this mixing process. Decreasing levels of SO4 and increasing levels of H2S and CH4 contents in lake water with depth, strongly suggests anaerobic bacterial processes are occurring through decomposition of organic matter under anoxic conditions in the sediment and in the water column. Sulfate reduction and methanogenesis processes coexist and play a pivotal role in the anaerobic environment of the Lake Averno. The sulfate reducing bacterial activity has been estimated in the range of 14-22 μmol.m-2.day-1. Total gas pressure of dissolved gases ranges between 800 and 1400 mbar, well below the hydrostatic pressure throughout the water column, excluding the possibility, at least at the survey time, of a limnic eruption. Vertical changes in the density of lake waters indicate that overturn may be triggered by cooling of epilimnetic waters below 7°C. This is a possible phenomenon in winter periods if atmospheric temperatures remain frosty for enough time, as occurred in February 2005. The bulk of these results strongly support the hypothesis that fish kill was caused by a series of events that began with the cooling of the epilimnetic waters with breaking of the thermal stratification, followed by lake overturn and the rise of toxic levels of H2S from the reduced waters near the lake bottom