2,305 research outputs found

    K X-Ray Energies and Transition Probabilities for He-, Li- and Be-like Praseodymium ions

    Full text link
    Theoretical transition energies and probabilities for He-, Li- and Be-like Praseodymium ions are calculated in the framework of the multi-configuration Dirac-Fock method (MCDF), including QED corrections. These calculated values are compared to recent experimental data obtained in the Livermore SuperEBIT electron beam ion trap facility

    Discounting in Games across Time Scales

    Get PDF
    We introduce two-level discounted games played by two players on a perfect-information stochastic game graph. The upper level game is a discounted game and the lower level game is an undiscounted reachability game. Two-level games model hierarchical and sequential decision making under uncertainty across different time scales. We show the existence of pure memoryless optimal strategies for both players and an ordered field property for such games. We show that if there is only one player (Markov decision processes), then the values can be computed in polynomial time. It follows that whether the value of a player is equal to a given rational constant in two-level discounted games can be decided in NP intersected coNP. We also give an alternate strategy improvement algorithm to compute the value

    Prediction, validation, and uncertainties of a nation‑wide post‑fire soil erosion risk assessment in Portugal

    Get PDF
    Wildfires are a recurrent and increasing threat in mainland Portugal, where over 4.5 million hectares of forests and scrublands have burned over the last 38 years. These fire-affected landscapes have suffered an intensification of soil erosion processes, which can negatively affect soil carbon storage, reduce fertility and forest productivity, and can become a source of pollutants. The main objective of the present study is to produce a post-fire soil erosion risk map for the forest and shrubland areas in mainland Portugal and assess its reliability. To this end, the semi-empirical Morgan–Morgan–Finney erosion model was used to assess the potential post-fire soil erosion according to distinct burn severity and climate scenarios, and the accuracy of the predictions was verified by an uncertainty analysis and validated against independent field datasets. The proposed approach successfully allowed mapping post-fire soil erosion in Portugal and identified the areas with higher post-fire erosion risk for past and future climate extremes. The outcomes of this study comprise a set of tools to help forest managers in their decision-making for post-fire emergency stabilization, ensuring the adequate selection of areas for mitigation to minimize the economic and environmental losses caused by fire-enhanced soil erosion.publishe

    Use of edible films and coatings in cheese preservation: Opportunities and challenges

    Get PDF
    In the last years, there has been a growing interest in the use of edible materials in food packaging. The cheese industry is clearly one of the sectors where these materials have a good opportunity for application, as shown by the recent developments on edible coatings and films for cheese. Edible coatings and films, besides its edibility, can be used to reduce weight loss and prevent the microbiological spoilage through the control of oxygen and carbon dioxide exchange rate and as a carrier of antimicrobial compounds. This review summarizes the recent results on edible films and coatings for cheese, the main developments and the main future perspectives for the application of these materials in the cheese industry.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/ BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Maria José Costa is recipient of a fellowship supported by a doctoral program (SFRH/BD/122897/2016) funded by the Portuguese Foundation for Science and Technology (FCT, POPH-QREN and FSE Portugal).info:eu-repo/semantics/publishedVersio

    Penalized regression on principal manifolds with application to combustion modelling

    Get PDF
    For multivariate regression problems featuring strong and non–linear dependency patterns between the involved predictors, it is attractive to reduce the dimension of the estimation problem by approximating the predictor space through a principal surface (or manifold). In this work, a new approach for non- parametric regression onto the fitted manifold is provided. The proposed penal- ized regression technique is applied onto data from a simulated combustion sys- tem, and is shown, in this application, to compare well with competing regression routines

    Functionalizing Ti-Surfaces through the EPD of Hydroxyapatite/NanoY₂O₃

    Get PDF
    Ceramic materials for skeletal repair and reconstruction are expanding to a number of different applications. Present research is addressing new compositions and performances to promote osseo-integration through metal coatings. Nanotechnology plays a key role in this research because nanostructures can be introduced into implants to functionalize them and/or to enhance their properties, such as the thermal or mechanical response. In this work, the insertion of Y₂O₃ nanoparticles into a hydroxyapatite (HA) coating of Ti using colloidal processing technology was developed. The suspensions of HA and Y₂O₃ nanoparticles were formulated with a focus on zeta potential, particle size distribution, and viscosity for the codeposition of both phases by electrophoresis. The microstructure of the nanocomposite coating was optimized by adjusting the main parameters of the electrophoretic deposition process. A threshold value of the applied electric field for the composite shaping was identified. The results demonstrate that the Y₂O₃ nanoparticles are homogeneously distributed in the coating and decrease in concentration as the distance from the substrate increases. As a consequence of the presence of the Y₂O₃, delays in the HA thermal decomposition and the improvement of metal–ceramic joining were observed.This work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under contracts MAT2009 14448 C02 01, MAT2012 38650 C02 02, and IPT 310000 2010 12

    Novel effects of strains in graphene and other two dimensional materials

    Full text link
    The analysis of the electronic properties of strained or lattice deformed graphene combines ideas from classical condensed matter physics, soft matter, and geometrical aspects of quantum field theory (QFT) in curved spaces. Recent theoretical and experimental work shows the influence of strains in many properties of graphene not considered before, such as electronic transport, spin-orbit coupling, the formation of Moir\'e patterns, optics, ... There is also significant evidence of anharmonic effects, which can modify the structural properties of graphene. These phenomena are not restricted to graphene, and they are being intensively studied in other two dimensional materials, such as the metallic dichalcogenides. We review here recent developments related to the role of strains in the structural and electronic properties of graphene and other two dimensional compounds.Comment: 75 pages, 15 figures, review articl

    Sulfates on Mars as Markers of Aqueous Processes: An Integrated Multidisciplinary Study of Minerals, Mars Analog sites and Recent Mission Data

    Get PDF
    Our analyses of sulfate minerals, analog sites, and Martian spectra and spectral images is focused on characterization of the Martian surface and in particular identification of aqueous processes there

    Characterization of edible beeswax-based oleogels aiming at food incorporation

    Get PDF
    São Paulo School of Advanced Sciences on Reverse Engineering of Processed Foods[Excerpt] Uprising concern and consciousness of consumers, regarding saturated fat consumption, and the consequent demand for healthier food products are well visible in today’s society. Such continuous challenges question the food industry to quickly present solutions. Replace saturated fats in the food processing chain can be accomplished with the incorporation of edible oilbased gels or oleogels, which try to reproduce common fat structural and sensorial characteristics. Oil gelation effectiveness is managed by the gelators’ crystallization behaviour, where beeswax rises as a good candidate. [...]info:eu-repo/semantics/publishedVersio
    • …
    corecore