Single and Double Photoionization and Photodissociation of Toluene by Soft X-rays in Circumstellar Environment

The formation of polycyclic aromatic hydrocarbons (PAHs) and their methyl derivatives occurs mainly in the dust shells of asymptotic giant branch (AGB) stars. The bands at 3.3 and 3.4 $\mu$m, observed in infrared emission spectra of several objects, are attributed C-H vibrational modes in aromatic and aliphatic structures, respectively. In general, the feature at 3.3 $\mu$m is more intense than the 3.4 $\mu$m. Photoionization and photodissociation processes of toluene, the precursor of methylated PAHs, were studied using synchrotron radiation at soft X-ray energies around the carbon K edge with time-of-flight mass spectrometry. Partial ion yields of a large number of ionic fragments were extracted from single and 2D-spectra, where electron-ion coincidences have revealed the doubly charged parent-molecule and several doubly charged fragments containing seven carbon atoms with considerable abundance. \textit{Ab initio} calculations based on density functional theory were performed to elucidate the chemical structure of these stable dicationic species. The survival of the dications subjected to hard inner shell ionization suggests that they could be observed in the interstellar medium, especially in regions where PAHs are detected. The ionization and destruction of toluene induced by X-rays were examined in the T Dra conditions, a carbon-rich AGB star. In this context, a minimum photodissociation radius and the half-life of toluene subjected to the incidence of the soft X-ray flux emitted from a companion white dwarf star were determined.Comment: 11 pages, 4 figures, accept for publication in Ap

Time needed to intubate and suction a manikin prior to instituting positive pressure ventilation: a simulation trial

Tracheal suctioning in non-vigorous newborn delivered through meconium-stained amniotic fluid (MSAF) is supposed to delay initiation of positive pressure ventilation (PPV), but the magnitude of such delay is unknown. To compare the time of PPV initiation when performing immediate laryngoscopy with intubation and suctioning vs. performing immediate PPV without intubation in a manikin model. Randomized controlled crossover (AB/BA) trial comparing PPV initiation with or without endotracheal suctioning in a manikin model of non-vigorous neonates born through MSAF. Participants were 20 neonatologists and 20 pediatric residents trained in advanced airway management. Timing of PPV initiation was longer with vs. without endotracheal suctioning in both pediatric residents (mean difference 13\ua0s, 95% confidence interval 8 to 18\ua0s; p\ua0< 0.0001) and neonatologists (mean difference 12\ua0s, 95% confidence interval 8 to 16\ua0s; p < 0.0001). The difference in timing of PPV initiation was similar between pediatric residents and neonatologists (mean difference 12 1\ua0s, 95% confidence interval 12 7 to 6\ua0s; p\ua0= 0.85). Conclusions: Performing immediate laryngoscopy with intubation and suctioning was associated with longer\u2014but not clinically relevant\u2014time of initiation of PPV compared with immediate PPV without intubation in a manikin model. While suggesting negligible delay in starting PPV, further studies in a clinical setting are warranted. Registration: clinicaltrial.gov NCT04076189.What is Known:\u2022 Management of the non-vigorous newborn delivered through meconium-stained amniotic fluid remains still controversial.\u2022 Tracheal suctioning in non-vigorous newborn delivered through meconium-stained amniotic fluid is supposed to delay initiation of positive pressure ventilation, but the magnitude of such delay is unknown.What is New:\u2022 Performing immediate ventilation without intubation was associated with shorter\u2014but not clinically relevant\u2014time of initiation of ventilation compared to immediate laryngoscopy with intubation and suctioning in a manikin model.\u2022 Further studies in a clinical setting are warranted

Dispersed generation to provide ancillary services: AlpStore project

In the future, electrical systems should be able to integrate all users at the same time and guarantee power quality, stability and safety over time. The integration of renewable energy sources leads to new issues involving the intermittence of this generation typology. A high penetration of intermittent power plants will reduce the capability of the system to overcome critical events (e.g. frequency oscillations and voltage profile perturbation). This work presents new regulation schemes/functions developed in the AlpStore project framework, devoted to managing dispersed generation in order to provide ancillary services to the main grid. The work developed can be split into two main items: reactive injection regulation and frequency control regulation. The first regulation is devoted to increasing the Hosting Capacity of the distribution grid (i.e. it results to be a local control), whereas the latter aims to guarantee the energy balance of the national electric grid (i.e. it could be classified as a grid control)