200 research outputs found
Remotely Controllable Robotic System to Detect Shallow Buried Objects with High Efficiency by Using an Holographic 4 GHz Radar
Rational modification of estrogen receptor by combination of computational and experimental analysis
In this manuscript, we modulate the binding properties of estrogen receptor protein by rationally modifying the amino acid composition of its ligand binding domain. By combining sequence alignment and structural analysis of known ER-ligand complexes with computational analysis, we were able to predict ER mutants with altered binding properties. These predictions were experimentally confirmed by producing single point variants with up to an order of magnitude increased binding affinity towards some estrogen disrupting chemicals and reaching an IC50 value of 2 nM for the 17뱉Ethinylestradiol ligand. Due to increased affinity and stability, utilizing such mutated ERs instead of the wild type ER as bio-recognition element would be beneficial in an assay or biosensor.JRC.I-Institute for Health and Consumer Protection (Ispra
Towards a Formal Verification Methodology for Collective Robotic Systems
We introduce a UML-based notation for graphically modeling
systemsâ security aspects in a simple and intuitive
way and a model-driven process that transforms graphical
specifications of access control policies in XACML. These
XACML policies are then translated in FACPL, a policy
language with a formal semantics, and the resulting policies
are evaluated by means of a Java-based software tool
Measurement report: Receptor modeling for source identification of urban fine and coarse particulate matter using hourly elemental composition
The elemental composition of the fine (PM2.5) and coarse
(PM2.5â10) fraction of atmospheric particulate matter was measured at an hourly time resolution by the use of a streaker sampler during a winter
period at a Central European urban background site in Warsaw, Poland. A
combination of multivariate (Positive Matrix Factorization) and wind-
(Conditional Probability Function) and trajectory-based (Cluster Analysis)
receptor models was applied for source apportionment. It allowed for the
identification of five similar sources in both fractions, including sulfates, soil dust, road salt, and traffic- and industry-related sources. Another two sources, i.e., Cl-rich and wood and coal combustion, were solely identified in the fine fraction. In the fine fraction, aged sulfate aerosol related to emissions from domestic solid fuel combustion in the outskirts of the city was the largest contributing source to fine elemental mass (44â%), while traffic-related sources, including soil dust mixed with road dust, road dust, and traffic emissions, had the biggest contribution to the coarse elemental mass (together accounting for 83â%). Regional transport of aged aerosols and more local impact of the rest of the identified sources played a crucial role in aerosol formation over the city. In addition, two intensive Saharan dust outbreaks were registered on 18 February and 8 March 2016. Both episodes were characterized by the long-range transport of dust at 1500 and 3000âm over Warsaw and the concentrations of the soil component being 7 (up to 3.5â”gâmâ3) and 6 (up to 6.1â”gâmâ3) times higher than the mean concentrations observed during non-episodes days (0.5 and 1.1â”gâmâ3) in the fine and coarse fractions, respectively. The set of receptor models applied to the high time resolution data allowed us to follow, in detail, the daily evolution of the aerosol elemental composition and to identify distinct sources contributing to the concentrations of the different PM fractions, and it revealed the multi-faceted nature of some elements with diverse origins in the fine and coarse fractions. The hourly resolution of meteorological conditions and air mass back trajectories allowed us to follow the transport pathways of the aerosol as well.</p
In situ physical and chemical characterisation of the Eyjafjallajökull aerosol plume in the free troposphere over Italy
Abstract. Continuous measurements of physical and chemical properties at the Mt. Cimone (Italy) GAW-WMO (Global Atmosphere Watch, World Meteorological Organization) Global Station (2165 m a.s.l.) have allowed the detection of the volcanic aerosol plume resulting from the Eyjafjallajökull (Iceland) eruption of spring 2010. The event affected the Mt. Cimone site after a transport over a distance of more than 3000 km. Two main transport episodes were detected during the eruption period, showing a volcanic fingerprint discernible against the free tropospheric background conditions typical of the site, the first from April 19 to 21 and the second from 18 to 20 May 2010. This paper reports the modification of aerosol characteristics observed during the two episodes, both characterised by an abrupt increase in fine and, especially, coarse mode particle number. Analysis of major, minor and trace elements by different analytical techniques (ionic chromatography, particle induced X-ray emissionâparticle induced gamma-ray emission (PIXEâPIGE) and inductively coupled plasma mass spectrometry (ICP-MS)) were performed on aerosols collected by ground-level discrete sampling. The resulting database allows the characterisation of aerosol chemical composition during the volcanic plume transport and in background conditions. During the passage of the volcanic plume, the fine fraction was dominated by sulphates, denoting the secondary origin of this mode, mainly resulting from in-plume oxidation of volcanic SO2. By contrast, the coarse fraction was characterised by increased concentration of numerous elements of crustal origin, such as Fe, Ti, Mn, Ca, Na, and Mg, which enter the composition of silicate minerals. Data analysis of selected elements (Ti, Al, Fe, Mn) allowed the estimation of the volcanic plume's contribution to total PM10, resulting in a local enhancement of up to 9.5 ÎŒg mâ3, i.e. 40% of total PM10 on 18 May, which was the most intense of the two episodes. These results appear significant, especially in light of the huge distance of Mt. Cimone from the source, confirming the widespread diffusion of the Eyjafjallajökull ashes over Europe
In situ physical and chemical characterisation of the Eyjafjallajökull aerosol plume in the free troposphere over Italy
Continuous measurements of physical and chemical properties at the Mt.
Cimone (Italy) GAW-WMO (Global Atmosphere Watch, World Meteorological
Organization) Global Station (2165 m a.s.l.) have allowed the detection of the
volcanic aerosol plume resulting from the Eyjafjallajökull (Iceland) eruption of
spring 2010. The event affected the Mt. Cimone site after a transport over a distance
of more than 3000 km. Two main transport episodes were detected during the
eruption period, showing a volcanic fingerprint discernible against the free
tropospheric background conditions typical of the site, the first from April
19 to 21 and the second from 18 to 20 May 2010. This paper reports the
modification of aerosol characteristics observed during the two episodes,
both characterised by an abrupt increase in fine and, especially, coarse
mode particle number.
Analysis of major, minor and trace elements by different analytical
techniques (ionic chromatography, particle induced X-ray emissionâparticle
induced gamma-ray emission (PIXEâPIGE) and inductively
coupled plasma mass spectrometry (ICP-MS)) were performed on
aerosols collected by ground-level discrete sampling. The resulting database
allows the characterisation of aerosol chemical composition during the
volcanic plume transport and in background conditions. During the passage of
the volcanic plume, the fine fraction was dominated by sulphates, denoting
the secondary origin of this mode, mainly resulting from in-plume oxidation
of volcanic SO2. By contrast, the coarse fraction was characterised by
increased concentration of numerous elements of crustal origin, such as Fe,
Ti, Mn, Ca, Na, and Mg, which enter the composition of silicate minerals.
Data analysis of selected elements (Ti, Al, Fe, Mn) allowed the estimation
of the volcanic plume's contribution to total PM10, resulting in a local
enhancement of up to 9.5 ÎŒg mâ3, i.e. 40% of total PM10 on
18 May, which was the most intense of the two episodes. These results appear
significant, especially in light of the huge distance of Mt. Cimone from
the source, confirming the widespread diffusion of the Eyjafjallajökull
ashes over Europe
Carbonaceous aerosol in polar areas: First results and improvements of the sampling strategies
While more and more studies are being conducted on carbonaceous fractionsâorganic carbon (OC) and elemental carbon (EC)âin urban areas, there are still too few studies about these species and their effects in polar areas due to their very low concentrations; further, studies in the literature report only data from intensive campaigns, limited in time. We present here for the first time ECâOC concentration long-time data records from the sea-level sampling site of Ny-Ă
lesund, in the High Arctic (5 years), and from Dome C, in the East Antarctic Plateau (1 year). Regarding the Arctic, the median (and the interquartile range (IQR)) mass concentrations for the years 2011â2015 are 352 (IQR: 283â475) ng/m3 for OC and 4.8 (IQR: 4.6â17.4) ng/m3 for EC, which is responsible for only 3% of total carbon (TC). From both the concentration data sets and the variation of the average monthly concentrations, the influence of the Arctic haze on EC and OC concentrations is evident. Summer may be interested by high concentration episodes mainly due to long-range transport (e.g., from wide wildfires in the Northern Hemisphere, as happened in 2015). The average ratio of EC/OC for the summer period is 0.05, ranging from 0.02 to 0.10, and indicates a clean environment with prevailing biogenic (or biomass burning) sources, as well as aged, highly oxidized aerosol from long-range transport. Contribution from ship emission is not evident, but this result may be due to the sampling time resolution. In Antarctica, a 1 year-around data set from December 2016 to February 2018 is shown, which does not present a clear seasonal trend. The OC median (and IQR) value is 78 (64â106) ng/m3; for EC, it is 0.9 (0.6â2.4) ng/m3, weighing for 3% on TC values. The EC/OC ratio mean value is 0.20, with a range of 0.06â0.35. Due to the low EC and OC concentrations in polar areas, correction for the blank is far more important than in campaigns carried out in other regions, largely affecting uncertainties in measured concentrations. Through the years, we have thus developed a new sampling strategy that is presented here for the first time: samplers were modified in order to collect a larger amount of particulates on a small surface, enhancing the capability of the analytical method since the thermo-optical analyzer is sensitive to carbonaceous aerosol areal density. Further, we have recently coupled such modified samplers with a sampling strategy that makes a more reliable blank correction of every single sample possible
Classifying aerosol particles through the combination of optical and physical-chemical properties: Results from a wintertime campaign in Rome (Italy)
LABEC, the INFN ion beam laboratory of nuclear techniques for environment and cultural heritage
The LABEC laboratory, the INFN ion beam laboratory of nuclear techniques for
environment and cultural heritage, located in the Scientific and Technological Campus of
the University of Florence in Sesto Fiorentino, started its operational activities in 2004, after
INFN decided in 2001 to provide our applied nuclear physics group with a large laboratory
dedicated to applications of accelerator-related analytical techniques, based on a new 3 MV
Tandetron accelerator. The new accelerator greatly improved the performance of existing
Ion Beam Analysis (IBA) applications (for which we were using since the 1980s an old
single-ended Van de Graaff accelerator) and in addition allowed to start a novel activity of
Accelerator Mass Spectrometry (AMS), in particular for 14C dating. Switching between IBA
and AMS operation became very easy and fast, which allowed us high flexibility in programming
the activities, mainly focused on studies of cultural heritage and atmospheric aerosol
composition, but including also applications to biology, geology, material science and forensics,
ion implantation, tests of radiation damage to components, detector performance tests
and low-energy nuclear physics. This paper describes the facilities presently available in the
LABEC laboratory, their technical features and some success stories of recent applications
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