The Physical Structure of Protoplanetary Disks: the Serpens Cluster Compared with Other Regions

Spectral energy distributions are presented for 94 young stars surrounded by disks in the Serpens Molecular Cloud, based on photometry and Spitzer IRS spectra. Taking a distance to the cloud of 415 pc rather than 259 pc, the distribution of ages is shifted to lower values, in the 1-3 Myr range, with a tail up to 10 Myr. The mass distribution spans 0.2-1.2 Msun, with median mass of 0.7 Msun. The distribution of fractional disk luminosities in Serpens resembles that of the young Taurus Molecular Cloud, with most disks consistent with optically thick, passively irradiated disks in a variety of disk geometries (Ldisk/Lstar ~ 0.1). In contrast, the distributions for the older Upper Scorpius and Eta Chamaeleontis clusters are dominated by optically thin lower luminosity disks (Ldisk/Lstar ~ 0.02). This evolution in fractional disk luminosities is concurrent with that of disk fractions. The actively accreting and non-accreting stars (based on Ha data) in Serpens show very similar distributions in fractional disk luminosities, differing only in the brighter tail dominated by strongly accreting stars. In contrast with a sample of Herbig Ae/Be stars, the T Tauri stars in Serpens do not have a clear separation in fractional disk luminosities for different disk geometries: both flared and flat disks present wider, overlapping distributions. This result is consistent with previous suggestions of a faster evolution for disks around Herbig Ae/Be stars. Furthermore, the results for the mineralogy of the dust in the disk surface do not show any correlation to either stellar and disk characteristics or mean cluster age in the 1-10 Myr range probed here. A possible explanation for the lack of correlation is that the processes affecting the dust within disks have short timescales, happening repeatedly, making it difficult to distinguish long lasting evolutionary effects. [abridged]Comment: ApJ in pres

Estimating the sustainability of carbon nanotube composites: reprocessing studies

Polylactide (PLA) has attracted particular attention in the area of environmentally degradable polymer materials. Some applications require the incorporation of a reinforcement material to produce a composite with specific properties. It was observed that PLA /carbon nanotube (CNT) composites present adequate properties for liquid sensing. The health risks involved in the use of carbon nanotubes are still under study, and thus the application of these materials must be planned with caution. From the point of view of environmental protection, recycling the CNT composites is the way to reduce these problems to the lower level possible, by maximizing they life cycle. The work presented reports the processing of PLA/CNT composite monofilaments, produced for sensing applications, and their reprocessing to form new monofilament composites. The monofilaments were reprocessed three times, and the tensile properties and electrical resistivity was measured. The melt flow index of the nanocomposites after each reprocessing step was measured. The thermal stability was evaluated by thermogravimetric analysis. It was observed that, although the melt flow index increased with reprocessing cycles, the tensile and electrical properties of the monofilaments produced after reprocessing were not affected, even after the fourth processing cycle. The thermal stability of the filaments was comparable after each processing cycle.Project Inteltex, FP

Patterns of Eating Behavior among 13-Year-Old Adolescents and Associated Factors: Findings from the Generation XXI Birth Cohort

Eating behavior adopted during adolescence may persist into adulthood. The aims of this study were to identify eating behavior patterns among Portuguese adolescents and to explore whether groups differ in terms of early life and family characteristics, severity of depressive symptoms, and body mass index (BMI) z-score. Participants were 3601 13-year-olds enrolled in the birth cohort Generation XXI. Eating behavior was assessed using the self-reported Adult Eating Behavior Questionnaire (AEBQ), validated in this sample. The severity of depressive symptoms was measured through the Beck Depression Inventory (BDI-II), and data on sociodemographic and anthropometrics were collected at birth and 13-years-old. Latent class analysis was conducted, and associations were estimated using multinomial logistic regression models. Five patterns of individuals were identified: Picky eating, Disinterest towards food, Food neophilia, Emotional eating, and Food attractiveness. The adolescents' sex, maternal education, BMI z-score, and severity of depressive symptoms were significantly associated with the identified patterns. In particular, adolescents with a higher BMI z-score were more likely in Food neophilia while individuals with more severe depressive symptoms were in the Picky eating, Emotional eating, and Food attractiveness patterns. These findings suggest a starting point for the development and planning of targeted public health interventions

Heavy neutrino-antineutrino oscillations at the FCC-ee

We discuss the impact of heavy neutrino-antineutrino oscillations (NNOs) on heavy neutral lepton (HNL) searches at proposed electron-positron colliders such as the future circular $e^+e^-$ collider (FCC-ee). During the $Z$ pole run, HNLs can be produced alongside a light neutrino or antineutrino that escapes detection and can decay into a charged lepton or antilepton together with an off-shell $W$ boson. In this case, signals of lepton number violation only show up in the final state distributions. We discuss how NNOs, a typical feature of collider-testable low-scale seesaw models where the heavy neutrinos form pseudo-Dirac pairs, modify such final state distributions. For example, the forward-backward asymmetry (FBA) of the reconstructed heavy (anti)neutrinos develops an oscillatory dependence on the HNL lifetime. We show that these oscillations can be resolvable for long-lived HNLs. We also discuss that when the NNOs are not resolvable, they can nevertheless significantly modify the theory predictions for FBAs and observables such as the ratio of the total number of HNL decays into $\ell^-$ over ones into $\ell^+$, in an interval of the angle~$\theta$ between the HNL and the beam axis. Our results show that NNOs should be included in collider simulations of HNLs at the FCCee.Comment: 14 pages, 3 figure

Molecular studies in schizophrenia

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Monofilament composites of Co-continuous Polyamide12/Poly (Methyl Methacrylate) and carbon nanotubes

Polymer-polymer/carbon nanotube (CNT) composite fibres with a co-continuous morphology were developed, aiming at structural and functional applications. The objective was to produce fibres with electrical conductivity, provided by the incorporation of CNT, maintaining the mechanical properties at a level that allowed typical textile processing. If this goal is achieved, then the fibres may be incorporated into a fabric at specific locations, and be used for sensing purposes. The present work reports the processing of co-continuous bi-polymer CNT composites and the production of mono-filaments with a range of drawing ratios. The composites were processed by melt mixing in a twin-screw extruder. Polyamide 12 (PA12), Poly(methylmetacrylate) (PMMA) and CNT were blended at 78:18:4 weight ratios, incorporated at various positions along the extruder barrel. The CNT remained in the PA12 phase, irrespective of the polymer order of admission in the extruder. In order to achieve electrical conductivity in the CNT/polymer blend a double percolation has to be attained [1], meaning that the polymer bearing the CNT has to be continuously distributed along the fibre, and the CNT dispersed inside that polymer have to form a conductive network. Monofilaments were drawn, their morphology and electrical conductivity were studied. Electrically conductive monofilaments were produced, even at the higher drawing ratios tested.Fundação para a Ciência e a Tecnologia (FCT

On the simulation of the filling stage of thermoplastic injection molding using the open-source solver openInjMoldSim

NORTE-07-0162-FEDER-000086 and the Minho Advanced Computing Center (MACC) for providing HP