Photoluminescence transient study of surface defects in ZnO nanorods grown by chemical bath deposition

Two deep level defects (2.25 and 2.03 eV) associated with oxygen vacancies (V$_o$) were identified in ZnO nanorods (NRs) grown by low cost chemical bath deposition. A transient behaviour in the photoluminescence (PL) intensity of the two V$_o$ states was found to be sensitive to the ambient environment and to NR post-growth treatment. The largest transient was found in samples dried on a hot plate with a PL intensity decay time, in air only, of 23 and 80 s for the 2.25 and 2.03 eV peaks, respectively. Resistance measurements under UV exposure exhibited a transient behaviour in full agreement with the PL transient indicating a clear role of atmospheric O$_2$ on the surface defect states. A model for surface defect transient behaviour due to band bending with respect to the Fermi level is proposed. The results have implications for a variety of sensing and photovoltaic applications of ZnO NRs

Correlating densities of centrality and activities in cities : the cases of Bologna (IT) and Barcelona (ES)

This paper examines the relationship between street centrality and densities of commercial and service activities in cities. The aim is to verify whether a correlation exists and whether some 'secondary' activities, i.e. those scarcely specialized oriented to the general public and ordinary daily life, are more linked to street centrality than others. The metropolitan area of Barcelona (Spain) is investigated, and results are compared with those found in a previous work on the city of Bologna (Italy). Street centrality is calibrated in a multiple centrality assessment (MCA) model composed of multiple measures such as closeness, betweenness and straightness. Kernel density estimation (KDE) is used to transform data sets of centrality and activities to one scale unit for correlation analysis between them. Results indicate that retail and service activities in both Bologna and Barcelona tend to concentrate in areas with better centralities, and that secondary activities exhibit a higher correlation

Project "Biodiversity MARE Tricase": a biodiversity inventory of the coastal area of Tricase (Ionian Sea, Italy) – Mollusca: Heterobranchia

The marine biodiversity of the Tricase coastal area (Ionian Sea, Italy) was investigated at the MARE Outpost (Avamposto MARE) between 2016 and 2017, with the help of citizen scientists and trained taxonomists. Among the most interesting groups encountered, heterobranch molluscs deserve a special mention. Altogether, 268 specimens were ascribed to this group and referred to 49 taxa. Notwithstanding the extensive literature on Mediterranean heterobranchs, two species proved to be new to the Italian coasts, the records of eight species represented their easternmost sightings in the Mediterranean Sea, and 13 taxa represented new records for the Ionian Sea. In addition, several feeding habits and phenological events were new to science. Although the European Union's Marine Strategy Framework Directive lists "Biodiversity is maintained" as the first descriptor in achieving "Good Environmental Status", our results highlighted the presence of conspicuous gaps in the knowledge of species distribution, taxonomy and ecology of heterobranch molluscs, indicating the necessity of even small-scale species checklists to understand biodiversity changes in worldwide biota

Assessment of orange fruit colonization by biocontrol yeasts

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Raman excitation profile of the G band in single-chirality carbon nanotubes

We present in this work measurements of the Raman excitation profile of the high-energy phonons (G band) in single-chirality (n,m) semiconducting single-wall carbon nanotubes using more than 70 laser excitation energies, and a theoretical description based on the third-order quantum model for Raman scattering. We show that the observed asymmetry in the G band Raman excitation profile is rigorously explained by considering all physical elements associated with Raman scattering in (n,m) carbon nanotubes, such as the existence of van Hove singularities in the electronic density of states and wave-vector dependence of the matrix elements of the Raman process. We conclude that the proposed violation of the Condon approximation is not a fundamental principle underlying the nanotube photophysics

Mobilkit: A Python Toolkit for Urban Resilience and Disaster Risk Management Analytics using High Frequency Human Mobility Data

Increasingly available high-frequency location datasets derived from smartphones provide unprecedented insight into trajectories of human mobility. These datasets can play a significant and growing role in informing preparedness and response to natural disasters. However, limited tools exist to enable rapid analytics using mobility data, and tend not to be tailored specifically for disaster risk management. We present an open-source, Python-based toolkit designed to conduct replicable and scalable post-disaster analytics using GPS location data. Privacy, system capabilities, and potential expansions of \textit{Mobilkit} are discussed.Comment: 3 pages, 1 figure, KDD KDD Workshop on Data-driven Humanitarian Mapping, 27th ACM SIGKDD Conferenc

Postural Control in Children with Cerebellar Ataxia

Controlling posture, i.e., governing the ensemble of involuntary muscular activities that manage body equilibrium, represents a demanding function in which the cerebellum plays a key role. Postural activities are particularly important during gait initiation when passing from quiet standing to locomotion. Indeed, several studies used such motor task for evaluating pathological conditions, including cerebellar disorders. The linkage between cerebellum maturation and the development of postural control has received less attention. Therefore, we evaluated postural control during quiet standing and gait initiation in children affected by a slow progressive generalized cerebellar atrophy (SlowP) or non-progressive vermian hypoplasia (Joubert syndrome, NonP), compared to that of healthy children (H). Despite the similar clinical evaluation of motor impairments in NonP and SlowP, only SlowP showed a less stable quiet standing and a shorter and slower first step than H. Moreover, a descriptive analysis of lower limb and back muscle activities suggested a more severe timing disruption in SlowP. Such differences might stem from the extent of cerebellar damage. However, literature reports that during childhood, neural plasticity of intact brain areas could compensate for cerebellar agenesis. We thus proposed that the difference might stem from disease progression, which contrasts the consolidation of compensatory strategies

The effect of sous vide packaging with rosemary essential oil on storage quality of fresh-cut potato

Selection of suitable raw materials and technologies are essential for the fresh-cut segment, since they represent key factors to be competitive in the modern markets. This study aimed at assessing the suitability of six early potato cultivars, grown in an experimental field, for minimal processing. In particular, the sous vide packaging method, in association with rosemary essential oil (REO), was evaluated as a strategy for the quality preservation of sliced potatoes. Physical, mechanical, chemical, microbiological and sensory characteristics were monitored in order to estimate qualitative changes of the product over refrigerated storage. Results demonstrated that the synergic use of REO and sous vide packaging had a positive effect on texture, and limited the growth of mesophilic bacteria and Enterobacteriaceae over the storage period; it also ensured a certain retention of ascorbic acid, total polyphenol content, and antioxidant activity. Hence, the proposed technological strategy could represent a valid solution for the preservation of sliced potatoes, contributing to limit, for the most suitable cultivars identified as Fontane and Marabel, the quality decrease until 11 days of cold storage

Quasielastic backscattering and barrier distributions for the 6, 7Li + 64Zn systems

Excitation functions of quasielastic scattering at backward angles were measured for the weakly bound 6Li and 7Li projectiles on a 64Zn target at energies around the Coulomb barrier. The corresponding barrier distributions were derived from the experimental cross sections. The experimental data were analyzed within the coupled-channel model using a double-folding potential as the bare potential. Inelastic excitations of the target, the 7Li first excited state, and 6Li, 7Li resonant state(s), corresponding to sequential breakup, were included in the calculations. The comparison between the data and coupled-channel predictions shows that the effects of channels not included in the calculations, such as direct breakup and transfers, are much larger for 6Li than for 7Li