402 research outputs found
Risk-based prioritization methodology for the classification of groundwater pollution sources
No full textWater management is one of the EU environmental priorities and it is one of the most serious challenges that today's major cities are facing. The main European regulation for the protection of water resources is represented by the Water Framework Directive (WFD) and the Groundwater Directive (2006/118/EC) which require the identification, risk-based ranking and management of sources of pollution and the identification of those contamination sources that threaten the achievement of groundwater's good quality status. The aim of this paper is to present a new risk-based prioritization methodology to support the determination of a management strategy for the achievement of the good quality status of groundwater. The proposed methodology encompasses the following steps: 1) hazard analysis, 2) pathway analysis, 3) receptor vulnerability analysis and 4) relative risk estimation. Moreover, by integrating GIS functionalities and Multi Criteria Decision Analysis (MCDA) techniques, it allows to: i) deal with several sources and multiple impacted receptors within the area of concern; ii) identify different receptors' vulnerability levels according to specific groundwater uses; iii) assess the risks posed by all contamination sources in the area; and iv) provide a risk-based ranking of the contamination sources that can threaten the achievement of the groundwater good quality status. The application of the proposed framework to a well-known industrialized area located in the surroundings of Milan (Italy) is illustrated in order to demonstrate the effectiveness of the proposed framework in supporting the identification of intervention priorities. Among the 32 sources analyzed in the case study, three sources received the highest relevance score, due to the medium-high relative risks estimated for Chromium (VI) and Perchloroethylene. The case study application showed that the developed methodology is flexible and easy to adapt to different contexts, thanks to the possibility to introduce specific relevant parameters identified according to expert judgment and data availability
A fast code using nonmagnetic measurements for RFX current and magnetic field profile reconstruction
No full textFast identification techniques of the plasma internal magnetic structure are needed for the real time control of the plasma current distribution in magnetic confinement devices. In this paper, a fast identification code using plasma internal nonmagnetic measurements is proposed and applied to the reversed field pinch experiment. The identification tool is based on a force-free ideal magnetohydrodynamic equilibrium model, using a parametric radial profile for the magnetic field and current density. A set of constraints on the internal magnetic distribution are derived from the Faraday rotation data given by a five-chord polarimeter, assuming the plasma density as given by an interferometric diagnostic. The code execution time is about a few second
Fattori di rischio perinatali, socio-economici ed infettivi per la malattia celiachia: uno studio di coorte di nascita attraverso record-linkage di flussi informativi correnti.
No full textWorkflow for the Assessment of ITER Plasma Control System Design
No full textThe plasma control system (PCS) for the first nonactive ITER operation phase will require simultaneous active monitoring and control of many continuous and discrete quantities. Considering the unique challenges ITER will face, all the controllers will be integrated and deployed with very little experimental time dedicated to PCS tuning and development. In order to maximize the efficiency of the ITER PCS design, a formal system engineering approach has been adopted. In a simplified way, the design process starts with the definition of the requirements. Functionalities are then designed and developed in order to meet these requirements. As a last step in the design process, it is important to assess that all the designed functionalities meet the associated requirements and that all the requirements are covered. The many different control functions will be designed and implemented in ITER PCS simulation platform (PCSSP) by different designing teams, both internal and external to ITER Organization. Although each team will be responsible for the independent assessment of the modules they deliver, an extra step is, nevertheless, necessary to guarantee that all the modules still continue to work when connected together. Therefore, integrated assessments will be built from independent assessments and will prove the controllers continue to meet the requirements. For this reason, it is necessary to have a unified workflow for the assessments performed by all the different designing teams. In fact, in order to guarantee a smooth integration assessment, it is important that all the assessments follow the same rules, use the same tools, are provided with the correct information, and are performed on the same platform. In this article, we present the proposed assessment workflow for ITER PCS components and some early impressions gathered from assessments of first delivered modules
A life cycle assessment study of European Space Agency's space tracking terminal
No full textThe transition to a low-carbon and resource-efficient circular economy is a political pillar of the EU and a priority for space agencies. Indeed, the space industry is pursuing sustainable development practices to reduce the environmental impacts. Life Cycle Assessment (LCA) is internationally recognized as the most appropriate methodology to estimate the environmental impacts of products, processes, and services and to evaluate the effectiveness of sustainability strategies related to reducing these negative externalities. To support the European Space Agency (ESA) in the process of planning more sustainable eco-design solutions, the objective of this paper is the development of a cradle-to-grave screening LCA study to assess the environmental impacts concerning the ESA's ground-based satellite tracking system based in New Norcia (AU) along its entire life cycle, including the tracking antenna and the photovoltaic panels. This scenario has been compared with 2 other scenarios to verify whether the use of photovoltaic panels has a benefit in terms of environmental impact (scenario A) and to understand the consequences in changing the location of the station, from New Norcia to Cebreros (E) by considering the change in the national energy mix from the Australian to the Spanish (scenario B). This study is one of the first attempts to apply the LCA methodology to the space sector, and its results, conducted according to ISO 14040/44 2021 guidelines and by means of the ReCiPe calculation method (2016), will be exploited by the ESA to plan a more sustainable eco-design for the construction of future space tracking stations
Poloidal magnetic field measurements in a reversed field pinch plasma by a far-infrared polarimeter
No full textA multichannel far-infrared (FIR) polarimeter has been installed in RFX, a Reversed Field Pinch (RFP) plasma experiment, to measure the poloidal magnetic field profile. The polarimeter uses a CH3OH FIR laser operating at lambda=118.8 mgrm. Faraday rotation measurements on five of six parallel diagnostic chords are used in preliminary investigations of poloidal field profiles. The experimental results are generally found in good agreement with the mu&p model predictions. The choice of the profile of mu = mu0 j·B/B2 is discussed. For the reconstruction of the magnetic field profiles a numerical filamentary current equilibrium code is described, where polarimetric data are included as constraints. An alternative method based on the best-fit of a three-parameter mu profile to the polarimetric data is also reported. Both methods provide reliable reconstructions of the plasma magnetic field and the results indicate the existence in RFX of hollow mu profiles
Revealing the architecture and composition of the sperm flagellum tip
No full textThe eukaryotic flagellum is a membrane-bound protruding organelle with a cytoskeleton of microtubules. Flagella are found in unicellular as well as multicellular organisms, performing a variety of functions. Motile flagella enable cell locomotion, like in protists or spermatozoa, but can also create flows of fluids or mucus, like in respiratory airways. Flagella also act as cellular “antennas”, as their surface can probe the environment with sensorial receptors. The flagellar ultrastructure is often regarded as widely conserved among eukaryotes, however significant differences have been reported for the structure of the distal flagellar tip between organisms. The tip is where the flagellum grows and where intra-flagellar transport must unload and load cargo, making it a hub of flagellar-specific processes that are still relatively under-explored.
In humans, genetic mutations that impair proper flagellar function cause primary ciliary dyskinesia, a collective term for numerous pathologies which are still not fully characterized. To elucidate the ultrastructure of the human flagellar tip, we performed cryo-electron tomography on intact spermatozoa, plunge-frozen in their native environment. The results revealed drastic differences compared to commonly studied model organisms. Additionally, a novel extensive structure (named TAILS) was discovered decorating the lumen of sperm tip microtubules. These results together highlight the power of cryo-electron tomography in displaying complex cellular structures in their native environment, as well as the importance of studying the human system directly.
Lastly, a multi-pronged approach was designed to biochemically identify and characterize TAILS, based on a reverse structural biology perspective. This included obtaining high-resolution structures of TAILS produced with different cryo-electron microscopy techniques, the first ever flagellar tip proteome and an evolutionary overview of TAILS conservation
The new error field correction coil controller system in the Joint European Torus tokamak
No full textIntegration of magnetic and nonmagnetic measurements for current profile reconstruction in RFX
No full textA crucial issue in magnetically confined plasmas characterized by relevant internal current
redistribution, such as high beta and low field toroidal devices, is the determination of their internal
magnetic structure. The article presents a method for the integration of magnetic and nonmagnetic
measurements in a model which considers a plasma described by stationary ideal
magnetohydrodynamic equilibrium equations, with toroidal and poloidal plasma currents
represented by distributed discrete filaments and current sheets. The model also includes the massive
conductors representing the vessel, the shell, and the machine windings. The discrete current sets are
determined by using as input data the total currents flowing in the plasma, in the windings and in
the vessel, as deduced by external integral magnetic measurements. The obtained filamentary
current sets are then adjusted by imposing further constraints. One of the constraints is given by the
set of local magnetic field measurements provided by external pickup coils. A further and more
significant constraint is imposed by far infrared polarimeter, which gives an integral condition for
each implemented measurement chord. The method is validated by using experimental data from the
reversed field pinch Reversed Field eXperiment, and the results suggest that the current density
distribution is rather different from that usually predicted by conventional data inversion algorithms
Concepts, Design, and Development of a Multiplatform Framework for Real-Time Control in Nuclear Fusion
No full textThe paper discusses the requirements and presents an architectural overview of a new general-purpose framework for real-time control,
currently under development at the RFX laboratory. This represents the third generation of control framework developed at RFX. It takes into
account the experience gained in the development of the previous frameworks and exploits the evolution of computer technology, in particular,
the evolution of Linux towards real-time functionality and the availability of multicore CPUs in most general-purpose computing boards. The
framework will supervise data flow among the participating components, which may produce data, consume data, or apply some sort of
computation. Some system components have been already developed, while the architecture of others is still being refined. In particular, we are
going to integrate the infrastructure layer of the new framework with a real-time framework recently in use at JET. The aim of this collaboration
is a general purpose real-time system which can be used on both experiments
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