Compact formulae, dynamics and radiation of charged particles under synchro-curvature losses

We consider the fundamental problem of charged particles moving along and around a curved magnetic field line, revising the synchro-curvature radiation formulae introduced by Cheng and Zhang (1996). We provide more compact expressions to evaluate the spectrum emitted by a single particle, identifying the key parameter that controls the transition between the curvature-dominated and the synchrotron-dominated regime. This parameter depends on the local radius of curvature of the magnetic field line, the gyration radius, and the pitch angle. We numerically solve the equations of motion for the emitting particle by considering self-consistently the radiative losses, and provide the radiated spectrum produced by a particle when an electric acceleration is balanced by its radiative losses, as it is assumed to happen in the outer gaps of pulsar's magnetospheres. We compute the average spectrum radiated throughout the particle trajectory finding that the slope of the spectrum before the peak depends on the location and size of the emission region. We show how this effect could then lead to a variety of synchro-curvature spectra. Our results reinforce the idea that the purely synchrotron or curvature losses are, in general, inadequate to describe the radiative reaction on the particle motion, and the spectrum of emitted photons. Finally, we discuss the applicability of these calculations to different astrophysical scenarios.Comment: 9 pages, 5 figures, 2 tables. Accepted for publication in MNRAS main journal. References update

LCA di prodotto-servizio: il caso di studio di un lavamoto automatico

Il presente studio ha per oggetto l’applicazione della metodologia LCA ad un impianto di lavaggio automatico di motocicli, prodotto da un’azienda lombarda, Vema srl. Questo impianto sembra essere il primo nel suo genere a livello europeo, se non mondiale; non appena messa in commercio la macchina, l’azienda produttrice ha ricevuto infatti ordini anche dal Sud America, dalla Francia e dall’India. L’innovazione portata da questa macchina è quella di aver spostato specificamente sui motocicli il sistema di lavaggio automatico tipico delle automobili (tunnel ad avanzamento automatico), andando a riempire, economicamente, una nicchia di mercato ancora vuota. Tradizionalmente il lavaggio di motocicli viene svolto manualmente, mentre questo prodotto consente di lavare in maniera autonoma il proprio mezzo con un intervento manuale minimo ed una notevole riduzione dei consumi di acqua attraverso un sistema di riciclo

Time-stamped claim logic

The main objective of this paper is to define a logic for reasoning about distributed time-stamped claims. Such a logic is interesting for theoretical reasons, i.e., as a logic per se, but also because it has a number of practical applications, in particular when one needs to reason about a huge amount of pieces of evidence collected from different sources, where some of the pieces of evidence may be contradictory and some sources are considered to be more trustworthy than others. We introduce the Time-Stamped Claim Logic including a sound and complete sequent calculus. In order to show how Time-Stamped Claim Logic can be used in practice, we consider a concrete cyber-attribution case study

An assessment of the pulsar outer gap model. II: Implications for the predicted γ\gamma-ray spectra

One of the most important predictions of any gap model for pulsar magnetospheres is the predicted $\gamma$-ray spectra. In the outer gap model, the properties of the synchro-curvature radiation are sensitive to many parameters, whose realistic ranges have been studied in detail in an accompanying paper. There we demonstrated that the uncertainty in the radius of curvature, the magnetic field geometry, and the X-ray surface flux may affect by orders of magnitude the predicted flux and spectral peak in the $\gamma$-ray regime. Here, we present a systematic, numerical study of the impact of the different parameters on the particle dynamics along the gap and calculate the emitted synchro-curvature radiation along the trajectory. By integrating the emitted radiation along the gap and convolving it with a parametrized particle distribution, we discuss how the comparison with the wealth of {\em Fermi}-LAT data can be used to constrain the applicability of the model. The resulting spectra show very different energy peaks, fluxes and shapes, qualitatively matching the great variety of the observed {\em Fermi}-LAT pulsars. In particular, if we see a large fraction of photons emitted from the initial part of the trajectory, we show that the spectra will be flatter at the low-energy {\it Fermi}-LAT regime (100 MeV -- 1 GeV). This provides a solution for such observed flat spectra, while still maintain synchro-curvature radiation as the origin of these photons.Comment: 9 pages, 6 figures, 1 table. Accepted for pubblication in MNRAS main journal. References update

An assessment of the pulsar outer gap model. I: Assumptions, uncertainties, and implications for the gap size and the accelerating field

The popular outer gap model of magnetospheric emission from pulsars has been widely applied to explain the properties observed in $\gamma$-rays. However, its quantitative predictions rely on a number of approximations and assumptions that are usually overlooked. Here we examine them, reviewing the main ingredients entering in the model, evaluating their range of uncertainties. Usually, in the quantitative applications of the model, key parameters like the radius of curvature and the energies of the interacting photons are taken to be a fixed, single value. Instead, here we explore their realistic ranges, and the impact of these on the consistency of the model itself. We conclude that the popular evaluation of the trans-field size of the gap as a function of period and period derivative, is unreliable and affected by a huge dispersion. Last, the exploration of the possible values for the radius of curvature, the local magnetic field and other quantities deserve more attention for quantitative applications of the outer gap model, like the calculation of $\gamma$-ray spectra, which is the subject of an accompanying paper.Comment: 19 pages, 5 figures, 3 tables. Accepted for pubblication in MNRAS main journal. References update

Assessing the potential of molten carbonate fuel cell-based schemes for carbon capture in natural gas-fired combined cycle power plants

Abstract This work explores two configurations of natural gas-fired combined cycles (NGCC) with molten carbonate fuel cells (MCFC) for CO2 capture. Special attention is devoted to the selection of MCFC operating conditions (trade-off between CO2 capture and voltage losses), heat integration scheme, fuel use and CO2 purification. Two schemes are considered: (i) in the first "integrated" scheme, MCFC modules are installed between the gas turbine and the heat recovery steam generator (HRSG) to maximize the efficiency of the integrated power plant; (ii) in the second "non-integrated" layout, the MCFC is located downstream of the HRSG and a regenerative heat exchanger is designed to preheat cathode reactants up to the MCFC working temperature. This study includes a full techno-economic analysis of the two layouts based on a preliminary sizing of the key-components, and a sensitivity analysis on the CO2 utilization factor. Compared to a benchmark amine scrubbing process, the "integrated" configuration shows considerably better performance (Specific Primary Energy Consumption for CO2 Avoided - SPECCA = 0.31 MJ kgCO2-1; Cost of CO2 avoided - CCA = 50 $tCO2−1), whereas the "non-integrated" solution shows higher energy penalties but similar CO2 avoidance cost (SPECCA = 2.4  MJ  kgCO2−1; CCA = 76$ tCO2−1)

On Deriving Nested Calculi for Intuitionistic Logics from Semantic Systems

This paper shows how to derive nested calculi from labelled calculi for propositional intuitionistic logic and first-order intuitionistic logic with constant domains, thus connecting the general results for labelled calculi with the more refined formalism of nested sequents. The extraction of nested calculi from labelled calculi obtains via considerations pertaining to the elimination of structural rules in labelled derivations. Each aspect of the extraction process is motivated and detailed, showing that each nested calculus inherits favorable proof-theoretic properties from its associated labelled calculus

Calcareous Nannofossils and Paleoclimatic Evolution Across the Eocene-Oligocene Transition at IODP Site U1509, Tasman Sea, Southwest Pacific Ocean

The Eocene‐Oligocene transition (EOT; ∼34 Ma) was one of the most prominent global cooling events of the Cenozoic, coincident with the emergence of continental‐scale ice‐sheets on Antarctica. Calcareous nannoplankton experienced significant assemblage turnover at a time of long‐term surface ocean cooling and trophic conditions, suggesting cause‐effect relationships between Antarctic glaciation, broader climate changes, and the response of phytoplankton communities. To better evaluate the timing and nature of these relationships, we generated calcareous nannofossil and geochemical data sets (δ18O, δ13C and %CaCO3) over a ∼5 Myr stratigraphic interval recovered across the EOT from IODP Site U1509 in the Tasman Sea, South Pacific Ocean. Based on trends observed in the calcareous nannofossil assemblages, there was an overall decline of warm‐oligotrophic communities, with a shift toward taxa better adapted to cooler more eutrophic conditions. Assemblage changes indicate four distinct phases caused by temperature decrease and variations in paleocurrents: late Eocene warm‐oligotrophic phase, precursor diversity‐decrease phase, early Oligocene cold‐eutrophic phase, and a steady‐state cosmopolitan phase. The most prominent shift in the assemblages occurred during the ∼550 kyr‐long precursor diversity‐decrease phase, which has relatively high bulk δ18O and %CaCO3 values, and predates the phase of maximum glacial expansion (Earliest Oligocene Glacial Maximum–EOGM)

A case study of green design in electrical engineering: an integrated LCA/LCC analysis of an Italian manufactured HV/MV power transformer

The aim of this study is to present an experience of the application of the Sustainability Assessment Methodology to a traditional private business. It deals about a significant case study in which CESI S.p.A. applied an integrated LCA/LCC analysis to a 250 MVA HV/MV power transformer produced from the Italian Tamini Trasformatori S.r.l. and remanufactured from the traditional design- according to an innovative environmentally sustainable vision – changing the insulation material from mineral to ester oil. The study was the starting point to realize an Environmental Product Declaration and the preceding Product Category Rules, currently underway. Such an innovative and green product development tries to anticipate market demands, to improve the environmental performance and benefits of the energy transformation process, to increase the migration to bio and renewable sources solutions

Needs, expectations and consequences for the child growing up in a family with a parent with mental illness

Parental mental illness is considered one of the strongest risk-factors for development of offspring psychopathology. The lack of pan-European guidelines for empowering children of parents with mental illness led to EU project CAMILLE - Empowerment of Children and Adolescents of Mentally Ill Parents through Training of Professionals working with children and adolescents. The first task in this project, was to analyse needs, expectations and consequences for children, with respect to living with a parent with mental illness. The aim this paper is to report results of these analyses. The qualitative research was conducted in England, Finland, Germany, Italy, Norway, Poland and Scotland (N=96). There were 3 types of focus groups: (1) professionals (doctors, nurses, psychologists, social workers), (2) adult children and partners of a person with mental illness, (3) parents who have experienced mental illness during their parenthood. Framework analysis method was used. Results of the study highlighted that the main consequences for children of parental mental illness were role reversal, emotional and behavioural problems, lack of parent’s attention and stigma. The main needs of these children were emotional support, security and multidisciplinary help. Implications for practice are: (1) professionals working with parents with mental illness should be aware of the specific consequences for the children; (2) to empower children they should focus on them, but not excluding parents from the parental roles; (3) the multi-agency collaboration is necessary; (4) schools should provide counselling and teach staff and students about mental health problems to reduce stigm