1,042 research outputs found

    The consolidation process of the EU regulatory framework on nanotechnologies: within and beyond the EU case-by-case approach

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    The field of nanotechnologies has been the subject of a process of wide-ranging regulation, which covers two different trends. From the 2000s the European Commission and Parliament agreed on a type of adaptive, experimental and flexible approach, which had its apex with the Commission code of conduct on responsible nano-research developed through a set of consultations. In 2009 this initial agreement subsequently broke down and the EU started to develop a set of regulatory initiatives of a sectoral nature in several fields (cosmetics, food, biocides). Thus, the current arrangement of governance in the field of nanotechnologies appears to be a hybrid, which mixes forms belonging to the new governance method (consultations, self-regulation, agency, comitology committees, networking), working like a lung in the framework of EU policy, with more traditional tools belonging to the classic governance method (regulations, directives). This model of governance based on a case-by-case approach runs the risk of lacking coherence since it is exposed to sudden changes of direction when risks emerge and it has a weak anticipatory dimension due to both its excessive dependency on data collection and its insufficient use of upstream criteria, such as human rights, which should be used earlier, to allow anticipated intervention with a less intense use of hard law solutions

    Hydrological changes on water resources

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    Water is one of the essential elements for the nature and human being. The development of good practise of managing water resources are necessary to maintain sufficient availability and to support socio-economic activities and preserve natural ecosystems. For these reasons, it is fundamental to improve the knowledge of cause-effect relations that drives hydrological cycle, which determines water availability. Climate and land use (LU) are two of the main drivers of the water cycle and indeed, the knowledge of their influence on hydrology is a fundamental research question. Of course, the future water availability is strictly related to future climatic and LU scenarios and then a critical role is assumed by the prediction and assessment of these two. A climate and LU change impact study will be developed to investigate the near-future water availability in the Mediterranean area. In detail, on the basis of the state of art and the actual knowledge, the main objective of this dissertation is to estimate the probability density function (pdf) of annual surface runoff Q in transient climate and LU conditions in the island of Sardinia (Italy). The study case has been selected due to the ongoing important process of climate change, overexploitation and degradation of natural resources affecting the entire island (see e.g. ISPRA, ENEA and CIRCE studies). These analyses might have a strategic importance for stakeholders and government agencies that are interested in the management of water resources due to the well-known issue of water availability in the Mediterranean area. The knowledge of the near-future impact of climate and LU change could be useful to establish regional guidelines and good practices to avoid the ongoing reduction of water resources in Sardinia. After a detailed review of the existing methodologies for describing and detecting climate and LU change and their influence in hydrological processes, a methodology based on the Budyko’s theory that aims at assessing near future Q pdf in a closed form has been adopted. Five parameters are requested, referring to mean and standard deviation of annual rainfall P and annual potential evapotranspiration PET and Fu’s parameter ω. Sets of these parameters will be assessed to define different climatic and LU scenarios for the near future. EUROCORDEX and Land Use CORINE projects will be used to represent climate and LU in the present and in the near future. Results showed that in the near future Q will decrease due to the reduction of P and the increase of PET. The variability of Q will decrease due the reduction of variability of P. Finally, it has been observed that in Sardinia the main driver in the change of Q pdf will be climate change, while the LU plays a secondary role

    Cartesian Stiffness Matrix Mapping of a Translational Parallel Mechanism with Elastic Joints

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    This paper is devoted to calculating the Cartesian stiffness matrix of a translational parallel manipulator with elastic joints. The calculation takes into account the contribution of the Jacobian variation because of the change of manipulator configuration due to the elasticity and it covers the entire theoretical workspace of the manipulator. Three kineto‐static adimensional indices are proposed to measure the response of the manipulator in terms of stiffness

    Quale cristianesimo? L’iscrizione di Manasse a 'Hierapolis' di Frigia (Turchia)

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    The study of the inscription featuring Manasse’s Prayer (first half of VI century A.C.) from the House of the Painted Inscription in Hierapolis, Frigia (Turkey), today raises some very interesting questions not only on the origin of Christianity in Asia Minor, but also on the path of the religious liturgy and of penitential prayer inside private homes. In this specific instance, the issue of the use of the small room where the inscription was found, and its relationship with the rest of a home that features several decorative details, is brought up again

    The algebro-geometric study of range maps

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    Localizing a radiant source is a widespread problem to many scientific and technological research areas. E.g. localization based on range measurements stays at the core of technologies like radar, sonar and wireless sensors networks. In this manuscript we study in depth the model for source localization based on range measurements obtained from the source signal, from the point of view of algebraic geometry. In the case of three receivers, we find unexpected connections between this problem and the geometry of Kummer's and Cayley's surfaces. Our work gives new insights also on the localization based on range differences.Comment: 38 pages, 18 figure

    Investigation of cyclicity of kinematic resolution methods for serial and parallel planar manipulators

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    Kinematic redundancy of manipulators is a well-understood topic, and various methods were developed for the redundancy resolution in order to solve the inverse kinematics problem, at least for serial manipulators. An important question, with high practical relevance, is whether the inverse kinematics solution is cyclic, i.e., whether the redundancy solution leads to a closed path in joint space as a solution of a closed path in task space. This paper investigates the cyclicity property of two widely used redundancy resolution methods, namely the projected gradient method (PGM) and the augmented Jacobian method (AJM), by means of examples. Both methods determine solutions that minimize an objective function, and from an application point of view, the sensitivity of the methods on the initial configuration is crucial. Numerical results are reported for redundant serial robotic arms and for redundant parallel kinematic manipulators. While the AJM is known to be cyclic, it turns out that also the PGM exhibits cyclicity. However, only the PGM converges to the local optimum of the objective function when starting from an initial configuration of the cyclic trajector

    Development of a mechatronic system for the mirror therapy

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    This paper fits into the field of research concerning robotic systems for rehabilitation. Robotic systems are going to be increasingly used to assist fragile persons and to perform rehabilitation tasks for persons affected by motion injuries. Among the recovery therapies, the mirror therapy was shown to be effective for the functional recovery of an arm after stroke. In this paper we present a master/slave robotic device based on the mirror therapy paradigm for wrist rehabilitation. The device is designed to orient the affected wrist in real time according to the imposed motion of the healthy wrist. The paper shows the kinematic analysis of the system, the numerical simulations, an experimental mechatronic set-up, and a built 3D-printed prototype

    A nonparametric procedure to assess the accuracy of the normality assumption for annual rainfall totals, based on the marginal statistics of daily rainfall: an application to the NOAA/NCDC rainfall database

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    We develop a nonparametric procedure to assess the accuracy of the normality assumption for annual rainfall totals (ART), based on the marginal statistics of daily rainfall. The procedure is addressed to practitioners and hydrologists that operate in data-poor regions. To do so we use 1) goodness-of-fit metrics to conclude on the approximate convergence of the empirical distribution of annual rainfall totals to a normal shape and classify 3007 daily rainfall time series from the NOAA/NCDC Global Historical Climatology Network database, with at least 30 years of recordings, into Gaussian (G) and non-Gaussian (NG) groups; 2) logistic regression analysis to identify the statistics of daily rainfall that are most descriptive of the G/NG classification; and 3) a random-search algorithm to conclude on a set of constraints that allows classification of ART samples on the basis of the marginal statistics of daily rain rates. The analysis shows that the Anderson–Darling (AD) test statistic is the most conservative one in determining approximate Gaussianity of ART samples (followed by Cramer–Von Mises and Lilliefors’s version of Kolmogorov–Smirnov) and that daily rainfall time series with fraction of wet days fwd < 0.1 and daily skewness coefficient of positive rain rates skwd > 5.92 deviate significantly from the normal shape. In addition, we find that continental climate (type D) exhibits the highest fraction of Gaussian distributed ART samples (i.e., 74.45%; AD test at α = 5% significance level), followed by warm temperate (type C; 72.80%), equatorial (type A; 68.83%), polar (type E; 62.96%), and arid (type B; 60.29%) climates
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