1,196 research outputs found

    Combined in situ experimentation and modelling approaches to disentangle processes involved in the earliest stage of community assembly

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    The ecological process of community assembly is described as the succession of three phases: colonization, regulation and segregation. Early colonization remains the least studied and quantified phase of assembly. In order to fill this gap, an approach combining in situ experiments and modelling was proposed to study colonization by a benthic macrofauna community in open microcosms containing a single, non-limiting resource. The experiment was three months long. A total of 51 taxa were observed in the microcosms, but data analyses of the species composition and abundances revealed that five species, Capitella spp., Gammaropsis maculata, Erichtionus punctatus, Nereiphylla paretti and Harmothoe mariannae, explained most of the observed variation in the assembly process. The population dynamics of these species were simulated taking into account functional traits that govern individual interactions. The dynamic model simulated a demographic stochasticity due to low population densities that result from the small size of the experimental microcosms. Using this combined approach of experiments and modelling, we showed that predation interactions alone can account for the abundances and species composition of primary consumers during the transient phase of early colonization

    Benchmarking multi-criteria evaluation methodology's application for the definition of benchmarks in a negotiation-type public-private partnership. A case of study: The integrated action programmes of the Lazio Region

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    The growing scarcity of public financial in Italy, in opposition of the more significant problems of degradation of many urban areas, prompted the Legislature to standardise new processes of settlement transformation based on negotiation-type public-private partnerships (PPPN). However, these standards have not provided for benchmarks referring to the contents of partnerships or assessment procedures aimed at assessing the initiatives undertaken with respect to public utility objectives. This has often led to redevelopment initiatives geared more towards the satisfaction of private rather than public interests. The proposed methodology, structured on the integration of a benchmarking process with multi-criteria evaluation techniques known as benchmarking multi-criteria evaluation (BME) enables the definition of benchmarks through a participatory process of the different stakeholders involved in a PPPN to which the BME is applied. In order to verify the applicability of the proposed procedure, it has been applied to a type of PPPN: the integrated action programmes (PII) in the Lazio Region. The benchmarks can be used by Lazio’s administrators both for renewing the planning of the PII concerned and for verifying the quality of the initiatives within the same PPPN proces

    Effect of soda-lime glass on sintering and technological properties of porcelain stoneware tiles

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    The feasibility of waste glass recycling in ceramic tile production was assessed with special reference to fully vitrified products (porcelain stoneware). Soda-lime float or container glass was introduced, in replacement of sodic feldspar, in typical porcelain stoneware bodies (up to 10% wt) that underwent a laboratory simulation of tilemaking process, with a technological and compositional characterization of both fired and unfired tiles. Soda-lime glass had no significant effect on semi-finished products, but it influenced remarkably the firing behaviour, increasing shrinkage and closed porosity, decreasing open porosity and bulk density, and lowering mechanical and tribological performances. Waste glass promotes a more effective melting of quartz and a partial dissolution of mullite, leading to a more abundant and less viscous liquid phase, which accelerates the sintering kinetics. In conclusion, soda-lime glass can be used in small amounts (5% or less) with tolerable modifications of technological behaviour and performances of porcelain stoneware tiles

    The Role of counterions (Mo, Nb, Sb, W) in Cr-, Mn-, Ni- and V-doped rutile ceramic pigments. Part 2. Colour and technological properties

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    Industrial rutile pigments are manufactured using several chromophores: Cr (giving an orange hue), Mn (tan), Ni (yellow) and V (gray); a second element, the so-called counterion (i.e. Mo, Sb, Nb or W) is always added in order to achieve the desired coloration and/or improve the technological properties (e.g. chemico-physical resistance in ceramic bodies and glazes). The colour of these pigments is determined by both metal-ligand charge transfer (Ti4+ <-> O2-) and crystal field effects (transition metals substituting Ti4+ in octahedral coordination). Though the absorbance bands are broad and frequently overlapped, the UV-vis-NIR spectra suggest the occurrence of Cr3+, Mn2+, Mn3+, Ni2+, V3+, and V4+ as chromophores. Rutile pigments are suitable for through-body (up to 1250 degrees C) and glaze applications (up to 1100 degrees C). The best coloration of porcelain stoneware bodies is achieved with Sb or W as counterions, though the higher stability is ensured by Sb, but in the Ti-Ni-W system. The best glaze colours are accomplished by W-bearing pigments, which however are less stable than Nb- or Sb-containing ones, except than for the V + W coupling. This latter represents a new and very interesting Co-free and Cr-free black pigment for low temperature applications

    Effect of waste glass (TV/PC cathodic tube and screen) on technological properties and sintering behaviour of porcelain stoneware tiles

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    In the present work, the effects of TV and PC cathodic tube and screen glasses additions (5 and 10 wt.%) to a porcelain stoneware body, in replacement of feldspar, were evaluated simulating the tilemaking process. The presence of glass allows to preserve good technological and mechanical properties, complying with the latest requirements of the industrial practice. The sintering pattern of the glass-added bodies, evaluated by hot stage microscopy, is modified according to the different glass amount and typology; in particular, cathodic tube glass when present at 5 wt.% brings about a lowering of the maximum densification temperature and of the activation energy

    Editorial: Understanding Trajectories and Promoting Change From Early to Complex Skills in Typical and Atypical Development: A Cross-Population Approach

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    This Research Topic focuses on new research perspectives, methodologies, and protocols to understand trajectories and promote change in typical, at-risk, and atypical development. The interplay between early skills and the environment and the connections between theoretical and interventionmodels with an interdisciplinary, cross-domain and cross-population approach are addressed. These findings have important implications for clinicians and practitioners, who should take into account the specific characteristics of individual and interacting learning processes in planning interventions

    Microbiology managers: managerial training in the RItrain project

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    Leaders of research infrastructures (RIs) in Europe who are scientists require competencies in management. RItrain has addressed this issue by identifying skills required, locating relevant courses and finding gaps, whilst establishing a Master of Management programme. We describe how one contributing microbiology RI determined the most relevant skills.The RItrain project is funded by the European Commission, grant agreement number 654156.info:eu-repo/semantics/publishedVersio
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