1,248 research outputs found

    A combined electrochemical quartz-crystal microbalance probe beam deflection (EQCM-PBD) study of solvent and ion transfers at a poly[Ni(saltMe)]: modified elecrode during redox switching

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    The oxidative polymerization of the complex2,3-dimelhyl-N,N-bis( salicylidene)butane-2,3-diaminatonickel( n), [Ni(saltMe)], was monitored by the electrochemical quartz microbalance (EQCM) and crystal impedance techniques. Polymerisation efficiency was maintained throughout deposition of a film, which behaved rigidly, on the electrode

    The Stellar Content of Obscured Galactic Giant HII Regions V: G333.1--0.4

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    We present high angular resolution near--infrared images of the obscured Galactic Giant HII (GHII) region G333.1--0.4 in which we detect an OB star cluster. For G333.1--0.4, we find OB stars and other massive objects in very early evolutionary stages, possibly still accreting. We obtained KK--band spectra of three stars; two show O type photospheric features, while the third has no photospheric features but does show CO 2.3 μ\mum band--head emission. This object is at least as hot as an early B type star based on its intrinsic luminosity and is surrounded by a circumstellar disc/envelope which produces near infrared excess emission. A number of other relatively bright cluster members also display excess emission in the KK--band, indicative of disks/envelopes around young massive stars. Based upon the O star photometry and spectroscopy, the distance to the cluster is 2.6 ±\pm 0.4 kpc, similar to a recently derived kinematic (near side) value. The slope of the KK--band luminosity function is similar to those found in other young clusters. The mass function slope is more uncertain, and we find 1.3±0.2<Γ<1.1±0.2-1.3 \pm 0.2 < \Gamma < -1.1 \pm 0.2- for stars with M >5> 5 M_\odot where the upper an lower limits are calculated independently for different assumptions regarding the excess emission of the individual massive stars. The number of Lyman continuum photons derived from the contribution of all massive stars in the cluster is 0.2 ×\times 105010^{50} s1s^{-1} <NLyc<1.9< NLyc < 1.9 ×\times 105010^{50} s1s^{-1}. The integrated cluster mass is 1.0 ×\times 10310^{3} M<Mcluster<1.3M_\odot < M_{cluster} < 1.3 ×\times 10310^{3} MM_\odot.Comment: 31 pages, including 12 figures and 3 tables. Accepted for publication in the A

    An Investigation of Behavioural and Self-Reported Cognitive Empathy Deficits in Adolescents With Autism Spectrum Disorders and Adolescents With Behavioural Difficulties

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    © 2021 Vilas, Reniers and Ludlow. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). https://creativecommons.org/licenses/by/4.0/Deficits in empathy have been considered hallmarks in individuals with autism spectrum disorders (ASD) but are also considered to underlie antisocial behaviour associated with individuals with callous unemotional traits (CU). Research has suggested that individuals with autism spectrum disorders show more difficulties with cognitive empathy, and that individuals diagnosed with behaviours difficulties, characterised by CU traits and antisocial behaviour, demonstrate low affective empathy. In the current manuscript we present findings of two studies. The first study describes the validation of a new stimulus set developed for the empathic accuracy task, focused on its cognitive component. The second study compares the performance of 27 adolescents with ASD, 27 age matched typically developing adolescents and 17 adolescents with behavioural difficulties on the empathic accuracy task and a self-report measure of empathy. While, no differences were observed between the three groups across the empathy accuracy task, the adolescents with ASD and CD showed deficits in their cognitive empathy across the self-report measure. Adolescents with ASD showed lower scores in particularly their perspective taking abilities, whereas the adolescences with behavioural difficulties showed more difficulties with their online simulation. No differences in self-reported affective empathy across the three groups were observed. Clinical implications of the findings are discussed.Peer reviewedFinal Published versio

    Production of chitosan based films enriched with oregano essential oil for increased antibacterial activity

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    During the last years, there has been an increasing interest in developing bio-based active films to improve food safety, extend food shelf life and reduce the use of chemical preservatives. Chitosan, a deacetylated derivative of chitin, is a linear polysaccharide consisting of -(1 4) glucosamine and N-acetylglucosamine residues with potential to be used as a food packaging/coating material. This biopolymer can be used in a wide range of applications in the food industry due to several interesting properties such as its biodegradability, biocompatibility, non-toxicity, antimicrobial activity and versatile physical properties such as its film-forming capacity. Recently, different strategies have been explored to improve its natural properties for the development of food packaging/coating materials with enhanced antimicrobial activity. In particular, the incorporation in chitosan films of essential oils (EO) with acknowledged antibacterial properties, as an alternative of synthetic preservatives, is a matter of great interest since they are generally perceived by consumers as being “natural” food additives. Thus, the objective of this work was the production of chitosan films enriched with oregano EO to further improve the natural antimicrobial properties of chitosan. The obtained films which were then evaluated for its antibacterial activity

    Itokawa's Opposition Surge seen by Hayabusa/AMICA

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    Using images acquired by the Hayabusa/AMICA instrument, along with Lederer et al.'s (2008) ground-based observations, we re-examine Itokawa's disk-integrated phase curve. The AMICA images provide critical opposition measurements (between 0.7deg - 9.3deg phase at 540 nm). Using Hapke's model (2012), we fit the updated phase curves at 5 different wavelengths. Preliminary modeling results show a range of porosity values commensurate with those in the literature (Ostro et al. 2004, Gundlach and Blum, 2012, Kiuchi and Nakamura 2014) based on an impact-generated grain size distribution function and grain size range evaluations from the AMICA data (Yano et al. 2006). This wide range on a global porosity is indicative of a highly variable porosity across the surface. The derived transport mean free path and the generally forward scattering nature of the global regolith are indicative of scattering centers (such as cracks, bubbles, and inclusions) that are small compared to the observational wavelengths. The derived regolith properties are compared with the imaging and sample analysis results, providing a test of the predictive capabilities of global disk-integrated measurements. This work suggests that the sub-pixel grain information could be extracted from the photometry, especially around opposition

    Spitzer Observations of Spacecraft Target 162173 (1999 JU3)

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    Near-Earth asteroid 162173 (1999 JU3) is the primary target of the Hayabusa-2 sample return mission, and a potential target of the Marco Polo sample return mission. Earth-based studies of this object are fundamental to these missions. We present a mid-infrared spectrum (5-38 microns) of 1999 JU3 obtained with NASA's Spitzer Space Telescope in May 2008. These observations place new constraints on the surface properties of this asteroid. To fit our spectrum we used the near-Earth asteroid thermal model (NEATM) and the more complex thermophysical model (TPM). However, the position of the spin-pole, which is uncertain, is a crucial input parameter for constraining the thermal inertia with the TPM; hence, we consider two pole orientations. In the extreme case of an equatorial retrograde geometry we derive a lower limit to the thermal inertia of 150 J/m^2/K/s^0.5. If we adopt the pole orientation of Abe et al. (2008a) our best-fit thermal model yields a value for the thermal inertia of 700+/-200 J/m^2/K/s^0.5 and even higher values are allowed by the uncertainty in the spectral shape due to the absolute flux calibration. The lower limit to the thermal inertia, which is unlikely but possible, would be consistent with a fine regolith similar to wthat is found for asteroid 433 Eros. However, the thermal inertia is expected to be higher, possibly similar to or greater than that on asteroid 25143 Itokawa. Accurately determining the spin-pole of asteroid 162173 will narrow the range of possible values for its thermal inertia.Comment: 4 pages, 2 figures; to be published as a Letter in Astronomy and Astrophysic

    Electrochemical behavior of a new precursor for the design of poly[Ni(salen)]-based modified electrodes

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    Wedescribe the potentiodynamic preparation and subsequent characterization of poly[Ni(3-MeOsaltMe)] films (surface concentration, 3 < ¡/nmol cm-2 < 350) in acetonitrile media. Coulometric and gravimetric (electrochemical quartz crystal microbalance, EQCM) data allow one to monitor the deposition process and show that the resultant films are physically and chemically stable
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