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Here we consider a wide class of advection-reaction-diffusion systems of interest in biomathematics. The equivalence generators with and without auxiliary conditions are derived. The search for differential invariants up to first order is performed. [ABSTRACT FROM AUTHOR]

In this paper we present the extension of a full-wave FEM model (COMSOL®+MATLAB®) - initially developed to compute the electromagnetic field in presence of the anisotropic inhomogeneous plasma of the Electron Cyclotron Resonance Ion Sources (ECRISs) [1] – to the Ion Cyclotron Range of Frequency (ICRF). The model - based on the full non-uniform dielectric tensor in "cold plasma" approximation - has been employed to study antenna geometries of increasing complexity. Various antenna types have been analyzed, starting from single flat strap up to the two straps of an antenna option considered for the Divertor Tokamak Test facility (DTT) [2]. The results have been compared, cross-checked and validated with a simpler COMSOL-based tool [3] and with the TOPICA code [4]. [ABSTRACT FROM AUTHOR]

Ion Cyclotron Range of Frequencies (ICRF) antennas are adopted in most of the existing nuclear fusion experiments. Their capability to couple high power to the plasma is known to be limited by a high input reflection coefficient and sometimes by high electric fields within the antenna box and immediately in front of it. In this work, we introduce a self-resonant IC strap antenna that can reach very good impedance matching, i.e. with very small power reflected back to the feeding lines; it is designed for the incoming Divertor Tokamak Test (DTT) experiment [1]. The antenna reaches matching for a bandwidth limited by the electrical size of the box, that is not compatible with operational planned frequency interval. Hence, we also propose an all-metal frequency structural tuning system; this allows launcher to be operated in frequency intervals of practical interest, e.g. from 60MHz to 90MHz. The overall antenna is a two-strap plug-in launcher that fits within DTT equatorial duct. After introducing the antenna concept, we describe a few optimization steps carried on through numerical codes, with a specific focus on the critical aspects mentioned above. [ABSTRACT FROM AUTHOR]

The basis of design for the Ion Cyclotron Range of Frequency (ICRF) antennas of the Divertor Tokamak Test facility (DTT) is defined and the most suitable design solutions abiding by such requirements are shown. DTT will be equipped with one, two or three ICRF modules – the final choice to be taken during the first years of operations – and each module will have two antennas. Each antenna has to reliably couple a radiofrequency (RF) power ≥1.5 MW in the range 60÷90 MHz to the single-null, 6 T, 5.5 MA, DTT scenario and allow for remote (dis)assembling and maintenance operations of its plasma-facing components. Most documented antenna concepts are considered and a large set of alternatives, based on toroidal arrays of two, three or four straps with different shapes and constraints, is quantitatively assessed in terms of RF performances. Two most promising candidates are identified: the one, selected to access a detailed design phase, relies on traditional radiating elements, the other is an innovative concept requiring some R&D. [ABSTRACT FROM AUTHOR]

Nowadays, alongside the traditional statistical and semi-probabilistic methods, through which it is possible to obtain an estimate of the road network performances whatever its geometric-functional configuration, the use of microscopic traffic simulation techniques is widespread, allowing a "dynamic" approach to the problem (e.g. evaluation of infrastructural interventions, traffic management, etc.). The traffic micro-simulation models are able to analyze and process, instant by instant, the movement of single vehicles on the network, on the basis of laws related to the vehicle movement and the driving behavior. Based on this premise, this study proposes an overview of traffic simulation models, with a focus on the advantages of microsimulation. In this direction, the paper presents an application to a real case study in the city of Catania (Italy), in order to evaluate the impact of different traffic regulation strategies in terms of level of service (LoS), road emissions and fuel consuption through scenario evaluations. First results demonstrates that traffic modeling and the implementation of microsimulation tools represent a valid support for the transport policies assessment, providing a basis for future research steps that will address the simulation of larger areas, through before and after analysis and the evaluation of different key performance indicators. [ABSTRACT FROM AUTHOR]

The mobility scenarios have been modified by the COVID-19 pandemic. Catastrophic and health events cause strong repercussions on daily activities and related mobility habits. In Italy, as in other contexts, we have witnessed a period of lockdown that has led to an almost zero travel. This work shows an overview of the changes in mobility choices before and after the COVID-19, with particular attention to sustainable forms of mobility such as shared mobility. It can reduce the use of private vehicles if properly incentivized and can be enhanced within the different forms of urban mobility, adopting ad hoc strategies and encouraging the active participation of the population in the assessment of critical issues and solutions towards sustainability. First results, analyzed at national level, provide a basis for future research steps on the assessment of the perceived safety by users in the use of different forms of mobility before and after the pandemic. [ABSTRACT FROM AUTHOR]

Nowadays, cities are increasingly required to be smart, sustainable, resilient and adaptive and, particularly following the COVID-19 pandemic, an integrated approach to transport planning needs to be adopted. In fact, European policies have adopted a series of limitations in the transport sector that led the scientific community to put into question the traditional transport planning process, by accelerating processes close to sustainability, started some time ago. In fact, many efforts in terms of strategies, initiatives and research have been made in the last decade to enhance new forms of sustainable urban mobility, in order to reduce the externalities associated with the transport sector. To achieve this goal, the European Commission has emphasized the integrated planning at all mobility levels. Among the other instruments, it has been identified a key role in the writing of the Sustainable Urban Mobility Plan (SUMP), its management and also through Intelligent Transport Systems (ITS). Based on this premise, the aim of this paper is to present first results of a wider research aimed at investigating the methodological and practical approaches to boost the strategy of integration between transport systems and urban planning by using ITS technologies and infomobility systems. The research can support further investigations in order to define specific Key Performance Indicators (KPIs) to measure and monitoring the impacts of technologies on developing smart cities and promoting sustainable mobility approaches, facing the urban planning and transport mobility issues of modern society. [ABSTRACT FROM AUTHOR]

The rapidly increasing transport in the last decades, characterized by high motorization rate especially in urban areas, constitutes a relevant contemporary issue addressed by scholars, planners and policy-makers, aiming to promote sustainable mobility. Nowadays, the COVID-19 crisis has influencing transport behaviour with a massive blow to public transport (PT) due to the social distancing. In this context, solutions represented by Demand Responsive Transport (DRT) can play a fundamental role not only in weak demand areas but also where the use of PT is relevant, as on-demand shuttles allow for more physical distancing and are cost-effective for more frequent routes. An essential point of the proposed study to be highlighted is the design of a structured multi-layered survey to identify the core attributes and the fundamental variables connected to the acceptance and potential use of a DRT service. The case study of a Mediterranean University has been analyzed, which is considering the opportunity to implement a public on-demand transport system, in order to enhance the efficiency of the current traditional public transport service and to discourage the use of the private vehicle. First results of an in-depth investigation are presented, which will serve to explore transport demand preferences towards flexible mobility and to identify the characteristics of the DRT service to be implemented. This work also lays the basis for further research with the aim of investigating the key aspects connected to innovative shared mobility solutions and thus supporting policy-makers and public and private transport companies to face new mobility issues. [ABSTRACT FROM AUTHOR]

The new AISHa ion source has been designed to generate high brightness multiply charged ion beams for hadrontheraphy applications, with high reliability, easy operations and fast maintenance. In order to get a compact machine the radial confinement is provided by a Hallbach-type permanent magnet hexapole structure, while axial confinement is allowed by four high field He-free superconducting magnets, allowing the optimization of the magnetic field gradient at ECR resonance. The present work shows the results of ion source commissioning along with next developments. Innovative active coupling techniques are planned to be tested to optimize the first pass wave absorption, which plays an important role in the coupling optimization of the new generation ECRIS. [ABSTRACT FROM AUTHOR]

The development and upgrade of ion sources for accelerators depends more and more on the optimization of the microwave-to-plasma coupling. Proton sources require to optimize the Electron Energy Distribution Function (EEDF) in the range of a few tens of eV. Multicharged ions sources require the optimization of EEDF in the keV scale depending on the needed charge state. The energy tail of EEDF must be damped since hot electrons are detrimental for the source performances. Last but not the least, also the spatial distribution of the EEDF within the plasma chamber should be known since RF power have to be deposited mainly in the regions of the plasma core near to the extraction hole and around the axis. In a few words, plasma parameters diagnostics will play a fundamental role for next developments and upgrade of existing sources, as well as for the design of new ones. This work presents the set of plasma diagnostics (including interferometer, polarimeter, optical emission spectroscopy, Langmuir probe, pin-hole camera and X rays detectors) already installed at the INFN-LNS testbenchs, the characterization of the EEDF as a function on the source parameters (magnetic field profile, microwave power and frequency and neutral pressure) and the expected consequences on the future design of ion sources. [ABSTRACT FROM AUTHOR]

At the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS) the beam commissioning of the high intensity Proton Source (PS-ESS) and the Low Energy Beam Transport (LEBT) line for the European Spallation Source (ESS) has been completed. The official project schedule was satisfied and the packaging for the shipment to Lund will shortly begin. Due to the high flexibility of the magnetic system, and to the innovative approach developed for the commissioning, we were able to test a huge amount of configurations (more than 400.000). The optimum source configuration that satisfy all requirements at the same time has been identified. The source is able to produce a stable total current between 40 and 125 mA (90 mA requested) through an 8 mm extraction aperture, with a proton fraction of up to 87% (75% requested). At the end of the LEBT the beam characteristics fully satisfy the ESS requirements: more than 70 mA of proton beam with 99% normalized beam emittance of 2.25 π.mm.mrad have been transported with intra pulse current fluctuation below ±1.5% (<±2% requested) and long term current fluctuation below ±3% (<±3.5% requested). High reliability of the overall system was measured with long duration test and fast beam recovery after vacuum break of 24 hours. Results and used strategy will be shown in details [ABSTRACT FROM AUTHOR]

Carbon, titanium and silver nanoparticles have been added to biomedical grade Ultra High Molecular Weight Poly Ethylene (UHMWPE) for the creation of "white-white" joints welded with a diode laser operating at 970 nm wavelength. The physical and surface features of the nanocomposite sheets, before and after the laser welding process, were measured in terms of surface roughness and wet ability (of distilled water, Simulated Synovial Fluid and human blood). Their adhesion strength and effect of the different nanoparticles on the joint’s physical features have been evaluated by a lap shear test. Experimental results highlight as diode laser energy changes the surface features in a different way depending on filler’s thermal conductivity while bulk features seems to be mainly due to filler size and hence, their dispersion degree inside the polymeric matrix. [ABSTRACT FROM AUTHOR]

In this paper, we consider a quite general class of advection reaction diffusion systems. As an example, a special case is discussed. [ABSTRACT FROM AUTHOR]

X-ray imaging and numerical simulations demonstrate that the RF power deposition in ECRIS plasmas is not concentrated in the near-axis region, as it would be desirable in order to maximize the ion beam brilliance. There are different arguments to explain this occurrence as due to the symmetry of the plasma chamber. In an "aperture coupled cylindrical cavity resonator, in fact, often off-axial eigenmode solution of Maxwell equations are excited leading to an off-axial concentration of the electromagnetic field. The "aperture-coupling of the rectangular waveguides with the cylindrical chambers (as it is normally for ECRIS) also suffers of an intrinsic, geometrical impedance mismatch. Both these issues suggest that a major optimization of RF coupling efficiency to ECRIS plasmas is still possible, provided that the overall geometry is changed. A reshaping of both the plasma chamber and related RF launching system - in a plasma microwave absorption oriented scenario - is considered as a possible solution, as well as the design of optimized launchers (taking inspiration from tools adopted in the thermonuclear-fusion) enabling "single-pass power deposition, not affected by cavity walls effects. [ABSTRACT FROM AUTHOR]

Selective deoxygenation of graphene oxide has been conducted with regard with the design and fabrication of graphene based devices. The ion beam lithography is considered to be a powerful method for patterning onto graphene oxide foil. A helium beam has been used for both direct patterning onto graphene oxide foil and simultaneous online characterisation of its structural and compositional changes. Scanning electron microscopy, energy dispersive spectroscopy and Rutherford backscattering spectrometry analyses have been accurately employed to reveal and monitor the deoxygenation of the graphene oxide foil demonstrating the reliability of the direct patterning using the ion beam lithography technique. [ABSTRACT FROM AUTHOR]

Since 2012, the INFN ion source group has been undertaking an intense activity on numerical modelling, started in a European context within the EMILIE Project, and presently continuing in the framework of the PANDORA project. The work mainly concerns the study of two aspects: on one hand, the ion beam-magnetized plasma interaction, a topic of interest in particular in the field of ECR-based charge breeding of radioactive ion beams. On the other hand, the energy coupling to plasma electrons by electromagnetic fields set-up in ECR sources and their consequent dynamics, including magnetostatic fields. Equations describing the particular physics case are implemented through the Langevin formalism in a Matlab environment, with a self-consistent 3D plasma modelling obtained by the interaction between COMSOL Multiphysics and Matlab. This contribution describes the stateof- the-art of the work on both the fronts: it will show an overview of the beam-plasma and wave-plasma interaction, giving details about electrons and ions dynamics. Perspectives on the continuation of the work will be also given. [ABSTRACT FROM AUTHOR]

This paper describes the modeling and the full wave numerical simulation of electromagnetic waves propagation and absorption in an anisotropic magnetized plasma filling the resonant cavity of an electron cyclotron resonance ion source (ECRIS). The model assumes inhomogeneous, dispersive and tensorial constitutive relations. Maxwell's equations are solved by the finite element method (FEM), using the COMSOL Multiphysics® suite. All the relevant details have been considered in the model, including the non uniform external magnetostatic field used for plasma confinement, the local electron density profile resulting in the full-3D non uniform magnetized plasma complex dielectric tensor. The more accurate plasma simulations clearly show the importance of cavity effect on wave propagation and the effects of a resonant surface. These studies are the pillars for an improved ECRIS plasma modeling, that is mandatory to optimize the ion source output (beam intensity distribution and charge state, especially). Any new project concerning the advanced ECRIS design will take benefit by an adequate modeling of self-consistent wave absorption simulations. [ABSTRACT FROM AUTHOR]

The laser-generated plasma, in non equilibrium conditions, has peculiar properties depending strongly on the laser parameters, on the target composition and on the target geometry. Different fast diagnostic techniques can be employed for the plasma characterization in terms of particles and photons emission, plasma temperature and density, ion energy distribution, angular emission, yield and electric field acceleration. Particular attention is devoted to the proton emission from hydrogenated targets and to the proton diagnostics by using time of flight techniques and Thomson parabola spectrometry. The diagnostic techniques will be presented and discussed on the base of the development of the ELIMED project. [ABSTRACT FROM AUTHOR]

We revisit some results on Aedes Aegypti due to ourself. In particular a new model is discussed from the point of view of symmetry methods. [ABSTRACT FROM AUTHOR]

In the framework of symmetry analysis, the class of 2×2 PDE systems to whom belong the Savage and Hutter model and the Iverson model is considered. New classes of exact solutions are found. [ABSTRACT FROM AUTHOR]

We consider the system of partial differential equations associated with the mathematical model for debris flows proposed by E.B. Pitman and L. Le (Phil. Trans. R. Soc. A, 363, 1573–1601, 2005) and analyze the problem of the hyperbolicity of the model. [ABSTRACT FROM AUTHOR]

The development of implantation techniques requires investigation of laser plasma as a potential source of multiply charged ions. The laser ion source delivers ions with kinetic energy and a charge state dependent on the irradiated target material and the parameters of the laser radiation used. By the focusing the laser beam on the solid target the higher current densities of ions than by using other currently available ion sources can be produced. The crucial issue for efficiency of the ion implantation technology is selection of proper laser beam characteristics. Implantation of different kinds of laser-produced ions into metals and organic materials were performed recently at the PALS Research Center in Prague, in cooperative experiments using 0.4-ns iodine laser pulses having energies up to 750 J at wavelength of 1315 nm or up to 250 J at wavelength of 438 nm. In this contribution we describe the characterization and optimization of laser-produced Ge ion streams as well as analysis of the direct implantation of these ions into Si and SiO2 substrates. The Ge target was irradiated with the use of laser pulses of energy up to 50 J at radiation intensities of ∼1011 W/cm2 and ∼2′1013 W/cm2. The implanted samples were placed along the target normal at distances of 17, 31 and 83 cm from the target surface. The ion stream parameters were measured using the time-of-fight method. The depth of ion implantation was determined by the Rutherford backscattering method (RBS). The maximum depth of implantation of Ge ions was ∼450 nm. These investigations were carried out for optimization of low and medium energy laser-generated Ge ion streams, suitable for specific implantation technique, namely for fabrication of semiconductor nanostructures within the SRAP “SEMINANO” project. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The ECLISSE experiment has been carried out by coupling a Laser Ion Source (based on a Nd:YAG laser (0.9 J / 9 ns, laser power densities <1011 W/cm2) to the SERSE superconducting ECR ion source. Cw beams of highly charged ions from metal samples without the use of ovens or sputtering technics were obtained in a variety of experimental conditions. The maximum charge states obtained from the ECRIS were 38+ for Ta and 41+ for Au. The peak current was obtained for 25+ and 29+ respectively and it was in the order of some tens of μA. In this work the analysis of some preliminary results obtained in afterglow mode will be also presented. We employed microwave pulse (length 4 msec) and laser pulse (length 9 nsec) with the same frequency (30 Hz) and variable relative phase. For appropriate phase values, a current enhancement of about one order of magnitude was observed. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The SERSE source has been efficiently working at the Laboratori Nazionali del Sud in Catania since 1998, by operating at 14 and 18 GHz, with a maximum power of about 2 kW. The performance of the source has been optimised for the beam injection into the K-800 Superconducting Cyclotron, i.e. the maximisation of the charge states was looked for, provided that the current of the beam was about 0.5 to 5 eµA, which is the typical analysed current for routinely operations. In 2000 a collaboration was established in order to test the behavior of SERSE at 28 GHz, so that a new operating domain could be studied, featuring a very dense plasma (up to 10[sup 13] cm[sup -3]) and a very high ion current (1 emA of Pb[sup 27+] is the goal of CERN and GSI for future heavy ion projects and 0.5 cma was considered to be a challenge for our experiment). Tests were carded out with a generator based on a gyrotron tube which was refurbished and made available by CEA; Xenon ions were chosen as a reference being the ionisation difficulty for Xe[sup 20+] similar to the one of P[sup 27+]. The results were excellent and the current of Xe[sup 20+] exceeded our expectations (more than 0.5 emA in afterglow and about 0.3 cma in dc mode). These results, obtained with a power limited to 4 kW in dc mode and 6.5 kW in pulsed mode because of the poor chamber cooling, can be considered as a remarkable step, in view of the third generation of electron cyclotron resonance ion source (ECRIS). The details of the experiments will be described, along with the design of the next superconducting ECRIS, the GyroSERSE source, which is expected to produce beam currents above 1 mA for intermediate charge states as well as very high charge states, 50[sup +] to 60[sup +] for the heaviest ions, with currents above 1 eµA. [ABSTRACT FROM AUTHOR]