82 research outputs found

    O 1s excitation and ionization processes in the CO2 molecule studied via detection of low-energy fluorescence emission

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    Oxygen 1s excitation and ionization processes in the CO2 molecule have been studied with dispersed and non-dispersed fluorescence spectroscopy as well as with the vacuum ultraviolet (VUV) photon?photoion coincidence technique. The intensity of the neutral O emission line at 845 nm shows particular sensitivity to core-to-Rydberg excitations and core?valence double excitations, while shape resonances are suppressed. In contrast, the partial fluorescence yield in the wavelength window 300?650 nm and the excitation functions of selected O+ and C+ emission lines in the wavelength range 400?500 nm display all of the absorption features. The relative intensity of ionic emission in the visible range increases towards higher photon energies, which is attributed to O 1s shake-off photoionization. VUV photon?photoion coincidence spectra reveal major contributions from the C+ and O+ ions and a minor contribution from C2+. No conclusive changes in the intensity ratios among the different ions are observed above the O 1s threshold. The line shape of the VUV?O+ coincidence peak in the mass spectrum carries some information on the initial core excitatio

    A public early intervention approach to first-episode psychosis: Treated incidence over 7 years in the Emilia-Romagna region

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    AimTo estimate the treated incidence of individuals with first-episode psychosis (FEP) who contacted the Emilia-Romagna public mental healthcare system (Italy); to examine the variability of incidence and user characteristics across centres and years. MethodsWe computed the raw treated incidence in 2013-2019, based on FEP users aged 18-35, seen within or outside the regional program for FEP. We modelled FEP incidence across 10 catchment areas and 7 years using Bayesian Poisson and Negative Binomial Generalized Linear Models of varying complexity. We explored associations between user characteristics, study centre and year comparing variables and socioclinical clusters of subjects. ResultsThousand three hundred and eighteen individuals were treated for FEP (raw incidence: 25.3 / 100.000 inhabitant year, IQR: 15.3). A Negative Binomial location-scale model with area, population density and year as predictors found that incidence and its variability changed across centres (Bologna: 36.55; 95% CrI: 30.39-43.86; Imola: 3.07; 95% CrI: 1.61-4.99) but did not follow linear temporal trends or density. Centers were associated with different user age, gender, migrant status, occupation, living conditions and cluster distribution. Year was associated negatively with HoNOS score (R = -0.09, p < .001), duration of untreated psychosis (R = -0.12, p < .001) and referral type. ConclusionsThe Emilia-Romagna region presents a relatively high but variable incidence of FEP across areas, but not in time. More granular information on social, ethnic and cultural factors may increase the level of explanation and prediction of FEP incidence and characteristics, shedding light on social and healthcare factors influencing FEP

    Interatomic Coulombic Decay Processes after Multiple Valence Excitations in Ne Clusters

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    We present a comprehensive analysis of autoionization processes in Ne clusters (~5000 atoms) after multiple valence excitations by free electron laser radiation. The evolution from 2-body interatomic Coulombic decay (ICD) to 3-body ICD is demonstrated when changing from surface to bulk Frenkel exciton excitation. Super Coster-Kronig type 2-body ICD is observed at Wannier exciton which quenches the main ICD channel

    Slow interatomic Coulombic decay of multiply excited neon clusters

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    Ne clusters ( 3c5000 atoms) were resonantly excited (2p\u21923s) by intense free electron laser (FEL) radiation at FERMI. Such multiply excited clusters can decay nonradiatively via energy exchange between at least two neighboring excited atoms. Benefiting from the precise tunability and narrow bandwidth of seeded FEL radiation, specific sites of the Ne clusters were probed. We found that the relaxation of cluster surface atoms proceeds via a sequence of interatomic or intermolecular Coulombic decay (ICD) processes while ICD of bulk atoms is additionally affected by the surrounding excited medium via inelastic electron scattering. For both cases, cluster excitations relax to atomic states prior to ICD, showing that this kind of ICD is rather slow (picosecond range). Controlling the average number of excitations per cluster via the FEL intensity allows a coarse tuning of the ICD rate

    Dissociative Recombination of H 3

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    Pyrimidine and thiadiazole derivatives as inhibitors of copper corrosion in sodium chloride solution

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    Pyrimidine and thiadiazole derivatives have been evaluated as prefilming agents and corrosion inhibitors of OFHC copper, Al-brass, 90Cu-10Ni and 70Cu-30Ni, in sodium chloride solutions. Two series of compounds have been tested: - 2-mercaptopyrimidine, 2,4-dimercaptopyrimidine, 2-mercapto,4hydroxypyrimidine, 2-mercapto,4aminopyrimidine; - 2-amino,1,3,4-thiadiazole, 2-amino,5mercapto,1,3,4-thiadiazole, 2,5-dimercapto,1,3,4-thiadiazole, 2-amino,5/ethylthio)1,3,4-thiadiazole. The elctrodes have been prefilmed by immersion in aqueous solutions of the various compounds (conc. 2x10-4M; T=80°C; t=60 min). In some cases the influence of the variation of the prefilming parameters have been evaluated. The inhibiting effect of the various additives has been studied using 1x10-3M solutions. The protective effects due to the prefilming treatments or to the presence of the additives in chloride solutions have been evaluated by recording the anodic and cathodic polarization curves and the polarization resistance values during 300-hour immersion tests in non deareated 0.1M NaCl solutions at 40°C. The nalysis of the obtained results allowed to differentiate the protectivity of the various compounds

    Double photoionization of simple molecules of astrochemical interest

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    An experimental and computational investigation characterizing the processes following the double photoionization of the methyloxirane and N-methylformamide molecules has been reported. The double photoionization experiments have been performed at the Elettra Synchrotron Facility of Trieste (Italy). Preliminary data show: (i) in the case of methyloxirane, six different two-body fragmentation processes leading to CH2+/C2H4O+,CH3+/C2H3O+,O+/C3H6+,OH+/C3H5+,C2H3+/CH3O+,C2H4+/CH2O+pairs of final ions; (ii) in the case of N-methylformamide, two main two-body fragmentation processes, leading to CH3++CH2NO+and H++C2H4NO+. The threshold’s energy for each dissociation channel is determined with the relative cross sections as a function of the investigated photon energy range. A careful analysis of recorded electron-ion-ion coincidence spectra mainly based on a Monte Carlo trajectory simulation is able to provide also the kinetic energy released (KER) distribution for the final ions of the investigated fragmentation reactions. These important experimental data are mandatory information to unravel the physical chemistry of the elementary processes induced by the interaction of photons, with simple relevant organic molecules: (i) the methyloxirane of astrochemical interest, being the first chiral molecule recently discovered in interstellar cloud Sagittarius B2; (ii) the N-methylformamide, being an important simple molecule containing the peptide bond, recently detected in the interstellar medium, in order to investigate its selective cleavage induced by UV photons. In the latter case, this can improve a deeper definition of formation/destruction routes in astrochemical environments of the more abundant formamide molecule
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