4,775 research outputs found

    Developing Digital Competences. Work learn trajectories in Italian School System

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    The work based learning is the core European dispositions on educational and training issue and a pillar of the Europe 2020 strategy (EUCOM 2009/C119/02). Therefore, the educational system has to increase the quality of standards and learning results in order to response adequately to competence needs and to permit the successful entrance of the youth in the world of work. The SWA is a coherent reaction. Indeed, the current literature lead to reflect on the SWA as a new prospective of school and world of work relationship (Arlotti and Barberis 2015), and as a resolution for the skills mismatch (Caputo and Capecchi 2016; Froy, Giguere, Hofer, 2009; A. Green, Hasluck, Hogarth, Reynolds, 2003). In a context which needs a different school that provides different types of skills, it is desirable that a policy instrument such as the SWA – became mandatory by the reform “La Buona Scuola” (Law 107/2015) – is included in the scientific debate, especially for its potential to contribute to renewal of the school system. Many authors encourage the scientific debate regarding the question to clarify the peculiar characteristics of the SWA model in Italy and to begin effective reflection on its revolutionary impact for the school system. According to Tino and Fideli (2015), the SWA is a process, not only as an experience, a fundamental methodology to promote the knowledge of the world of work and the development of competences (professional and citizenship) thanks to the interconnection between formal-informal learning and creative combination process between theory and practice

    Mathematical models and GNSS interference

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    Innovative Teaching and Digital Literacy in Preschool. App Content Analysis and Experimental Case Studies in a Sociological Perspective

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    The objective of this article is to illustrate, from the theoretical and methodological perspective, the construction of an experimental process of a “digital education app” in several preschools in the municipality of Rome. The general objective the project fits into is related to a sociological analysis, based on the relationship between theory and empirical research, of the effects of introducing digital media into preschool didactics. Preschools are a privileged site for observing and analyzing the formation and development of children’s capabilities (Nussbaum, 2000), since the plasticity of the child’s thought begins to be configured as early as preschool and evolves progressively taking into account the perceptive, sociocultural and behavioural conditions emerging from different educational agencies (Piaget, Inhelder, 1950). The article refers to the research project of the Mediamonitor Minori Observatory of the Sapienza University of Rome entitled “Media Usage in Pre-school. Analysis and Evaluation of the Influence of Digital Media on the Socialization of Children between 0-6”. The article retraces in particular the stages of the research strategy designed to structure a formative, experimental protocol to be experimented in some case studies in Rome and illustrates the main results

    Are carrier-to-noise algorithms equivalent in all situations?

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    This paper describes methods to estimate the carrier to noise ratio in GNSS application

    Benets of tight coupled architectures for the integration of GNSS receiver and Vanet transceiver

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    Vehicular adhoc networks (VANETs) are one emerging type of networks that will enable a broad range of applications such as public safety, traffic management, traveler information support and entertain ment. Whether wireless access may be asynchronous or synchronous (respectively as in the upcoming IEEE 8021.11p standard or in some alternative emerging solutions), a synchronization among nodes is required. Moreover, the information on position is needed to let vehicular services work and to correctly forward the messages. As a result, timing and positioning are a strong prerequisite of VANETs. Also the diffusion of enhanced GNSS Navigators paves the way to the integration between GNSS receivers and VANET transceiv ers. This position paper presents an analysis on potential benefits coming from a tightcoupling between the two: the dissertation is meant to show to what extent Intelligent Transportation System (ITS) services could benefit from the proposed architectur

    A fully digital model for Kalman filters

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    The Kalman filter is a mathematical method, whose purpose is to process noisy measurements in order to obtain an estimate of some relevant parameters of a system. It represents a valuable tool in the GNSS area, with some of its main applications related to the computation of the user PVT solution and to the integration of GNSS receivers with INS or other sensors. The Kalman filter is based on a state space representation, that describes the analyzed system as a set of differential equations that establishes the connections between the inputs, the outputs and the state variables of the analyzed system. In the continuous time domain there exists a large class of physical processes with a time evolution well described by means of stochastic differential equations. A typical problem is the need for an equivalent system in the discrete time, due to the discrete nature of the data to be processed. In the literature, it is quite common to solve this problem in the continuous time domain and to approximate the solution using a Taylor series approximation, to obtain an approximate discrete time version of the continuous time problem. By the way, other methods exist, based on the possibility to transform a continuous-time system to a discrete-time system by means of transformations from the Laplace complex plane to the z plane. These methods are widely used in the digital signal processing community, for example, to design digital filters from their analog counterparts. The main advantage of this approach is that it is very easily implemented by applying some mechanical rules. Moreover the nature of the approximation introduced by the Laplace-z transformation is a-priori known and clearly readable in the frequency domain. In the following the classical methods based on the Taylor approximation and on the Laplace-z transformations will be analyzed and compare

    GNSS signal acquisition in the presence of sign transitions

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    The next generation of Global Navigation Satellite Systems (GNSS), such as Galileo [1] and GPS modernization [2], will use signals with equal code and bit periods, which will introduce a potential sign transition in each segment of the signal processed in the acquisition block. If FFT is used to perform the correlations a sign transition occurring within the integration time may cause a splitting of the main peak of the Cross Ambiguity Function (CAF) into two smaller lobes along the Doppler shift axis [3]. In this paper a method to overcome the possible impairments due to the lobe splitting is proposed and validated by simulatio

    Le rappresentazioni del corpo "anaisthētos" nel "Corpus Hippocraticum": una 'via negativa' verso la conoscenza

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    This paper seeks to investigate the medical representations and descriptions of ἀναισθησία as we find them in the Hippocratic Corpus. It represents an attempt to analyze both the cognitive and the physiological aspects of perception and, above all, its distortion and/or absence in Hippocratic medicine. The medical phenomenology of ἀναισθησία will be considered in respect to both its outcomes (inability to perceive the outside world; inability to perceive one's internal states), but also in the light of, and in connection with, other phenomena like the absence/suspension of phonation, disturbances of breathing, alteration of the body's motor functions, and insensibility to pain

    Movimenti che disturbano lo spazio della narrazione. Micro-diario di un viaggio (im)possibile

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    Il movimento converte lo spazio in narrazione, scrive Giuliana Bruno nel suo Atlante (Bruno 2006). Viceversa, come si inventa lo spazio narrativo di corpi continuamente controllati, bloccati e anestetizzati nel loro movimento? O il movimento è altro e dovremmo cominciare a distinguerlo dalla mobilità (Cresswell 2006)? Prima scena. È il 2 settembre 2015. Ho un biglietto in mano per un treno fantasma. Un cordone di agenti della polizia circonda la maestosa stazione Keleti di Budapest e, amareggiata, penso che sarà impossibile entrare per chiunque. Tanto meno prendere il mio treno per Vienna. Ricordate il 2 settembre 2015? Le televisioni d’Europa gracchiavano all’unisono: una grande sollevazione da parte di coloro che vengono chiamati “migranti” o, se più fortunati, “rifugiati” perché i flussi dall’Ungheria verso l’Austria e la Germania erano stati interrotti. Intere famiglie siriane, afgane, pakistane avevano investito centinaia di euro per comprare i biglietti di quel treno della speranza, Budapest-Vienna, che alla fine ho dovuto prendere da sola. Per il mio passaporto. Ecco la mobilità, ecco l’immobilità: faccia a faccia. Seconda scena. Nella video installazione di Zanny Begg e Oliver Ressler, intitolata “The right of Passage” (2013), gli artisti propongono interviste con rifugiati e migranti, nonché intellettuali alla Toni Negri, Sandro Mezzadra e Arielle Azoulay. Il flusso del filmato è scandito da alcune parole-chiave: polis, città, cosmopolitismo, mondo in movimento. Alcune figure animate si muovono intanto tra le pagine dei passaporti mostrate dagli interlocutori e negano, attraverso i loro movimenti e le loro fughe nei buchi immaginari creati nelle pagine, la realtà e la validità dell’ordine espresso da quei documenti. C’est le mouvement. Questo intervento vuole porsi come un micro-diario: annotazioni distratte, piccoli abbagli teorici e contrappunti visuali di quella convulsa giornata in cui la barbara certezza che il movimento è un privilegio, non un diritto, o meglio che movimento e mobilità non possono più coincidere, si è depositata, come un residuo, sulla pelle di quei corpi interrotti e ancor più vigliaccamente sulla mia

    Optical detection of chemical species of environmental and biological relevance using molecular sensors and hybrid materials

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    [ES] La presente tesis doctoral titulada "Detección óptica de especies químicas de importancia ambiental y biológica utilizando sensores moleculares y materiales híbridos" se centra en el diseño, preparación, caracterización y evaluación de sensores químicos moleculares. El trabajo realizado se puede dividir en dos partes: (i) síntesis de sensores de cationes metálicos en disolución y (ii) síntesis y caracterización de nanopartículas híbridas orgánico-inorgánicas para el reconocimiento de especies químicas y biológicas. En el primer capítulo se introduce el marco en el que se engloban los fundamentos teóricos de la química supramolecular en que se basan los estudios prácticos realizados durante la presente tesis doctoral. A continuación, en el capítulo dos, se presentan los objetivos generales de la tesis. En el tercer capítulo se presenta un quimiodosímetro cromo-fluorogénico, capaz de detectar selectivamente cationes trivalentes entre cationes y aniones monovalentes y divalentes mediante una reacción de deshidratación en agua. En el cuarto capítulo se presenta una unidad (BODIPY) conectada electrónicamente con un macrociclo dithia-dioxa-aza. Las soluciones de acetonitrilo y agua-acetonitrilo 95: 5 v / v de la sonda mostraron una banda ICT en la zona visible y son casi no emisivas. Cuando se utilizó acetonitrilo como disolvente, la adición de Hg (II) y cationes metálicos trivalentes indujo un cambio hipsocrómico de la banda de absorción y mejoras moderadas de la emisión. Se obtuvo una respuesta altamente selectiva al utilizar medios competitivos como agua-acetonitrilo 95:5 v/v. En este caso, sólo el Hg (II) indujo un cambio hipsocrómico de la banda de absorción y una mejora marcada de la emisión. El quinto capítulo explora el desarrollo de sensores para berberina y amantadina. Dos moléculas de interés biológico por su uso como fármacos. Se han preparado tres sistemas de sensores basados en la aproximación de puertas moleculares. En concreto, sobre nanopartículas MCM-41 cargadas con rodamina B como unidad de señalización, se ha llevado a cabo la funcionalización con diversas aminas y el bloqueo de poros con cucurbituril CB7. Las aminas utilizadas son ii ciclohexilamina, bencilamina y amantadina. Los materiales obtenidos se han caracterizado por técnicas de difracción de rayos X y microscopía electrónica de transmisión confirmando la estructura mesoporosa de las nanopartículas. Los materiales preparados muestran una respuesta a la berberina y la adamantina, quitando el tapón y liberando el tinte fluorescente al medio. La respuesta de los materiales a las dos sustancias de interés (berberina y amantadina) depende de la estructura química de cada uno de los materiales en función de las constantes de afinidad entre el analito y CB7. Los resultados obtenidos abren el camino al uso de puertas moleculares como sensores de berberina y amantadina.[CA] La present tesi doctoral titulada "Detecció òptica d'espècies químiques d'importància ambiental i biològica utilitzant sensors moleculars i materials híbrids" se centra en el disseny, preparació, caracterització i avaluació de sensors químics moleculars. El treball realitzat es pot dividir en dues parts: (i) síntesi de sensors de cations metàl·lics en dissolució i (ii) síntesi i caracterització de nanopartícules híbrides orgànic-inorgànics per al reconeixement d'espècies químiques i biològiques. En el primer capítol s'introdueix el marc en el qual s'engloben els fonaments teòrics de la química supramolecular en què es basen els estudis pràctics realitzats durant la present tesi doctoral. A continuació, en el capítol dos, es presenten els objectius generals de la tesi. En el tercer capítol es presenta un quimiodosímetro crom-fluorogénic, capaç de detectar selectivament cations trivalents entre cations i anions monovalents i divalents mitjançant una reacció de deshidratació en aigua. En el quart capítol es presenta una unitat (BODIPY) connectada electrònicament amb un macrocicle dithia-dioxa-aza. Les solucions de acetonitril i aigua-acetonitril 95:5 v/v de la sonda van mostrar una banda ICT a la zona visible i són gairebé no emisivas. Quan es va utilitzar acetonitril com a dissolvent, l'addició de Hg (II) i cations metàl·lics trivalents va induir un canvi hipsocròmic de la banda d'absorció i millores moderades de l'emissió. Es va obtenir una resposta altament selectiva a l'utilitzar mitjans competitius com aigua-acetonitril 95:5 v/v. En aquest cas, només el Hg (II) va induir un canvi hipsocròmic de la banda d'absorció i una millora marcada de l'emissió. El cinquè capítol explora el desenvolupament de sensors per berberina i amantadina. Dues molècules d'interès biològic pel seu ús com a fàrmacs. S'han preparat tres sistemes de sensors basats en l'aproximació de portes moleculars. En concret, sobre nanopartícules MCM-41 carregades amb rodamina B com a unitat de senyalització, s'ha dut a terme la funcionalització amb diverses amines i el bloqueig de porus amb cucurbituril CB7. Les amines utilitzades són ciclohexilamina, bencilamina i amantadina. Els materials obtinguts s'han caracteritzat per tècniques iv de difracció de raigs X i microscòpia electrònica de transmissió confirmant l'estructura mesoporosa de les nanopartícules. Els materials preparats mostren una resposta a la berberina i la adamantina, llevant el tap i alliberant el tint fluorescent a l'mig. La resposta dels materials a les dues substàncies d'interès (berberina i amantadina) depèn de l'estructura química de cada un dels materials en funció de les constants d'afinitat entre l'anàlit i CB7. Els resultats obtinguts obren el camí a l'ús de portes moleculars com a sensors de berberina i amantadina.[EN] The present doctoral thesis entitled "Optical detection of chemical species of environmental and biological importance using molecular sensors and hybrid materials" focuses on the design, preparation, characterization and evaluation of molecular chemical sensors. The work carried out can be divided into two parts: (i) synthesis of metal cation sensors in solution and (ii) synthesis and characterization of hybrid organic-inorganic nanoparticles for the recognition of chemical and biological species. The first chapter introduces the framework that encompasses the theoretical foundations of supramolecular chemistry on which the practical studies carried out during this doctoral thesis are based. Next, in chapter two, the general objectives of the thesis are presented. In the third chapter, a chromium-fluorogenic chemodosimeter is presented, capable of selectively detecting trivalent cations by means of a dehydration reaction in water. The fourth chapter presents a new compound containing a BODIPY unit electronically connected with a dithia-dioxa-aza macrocycle. Acetonitrile and water-acetonitrile 95:5 v/v solutions of the probe showed an ICT band in the visible zone and were nearly non-emissive. When acetonitrile was used as a solvent, addition of Hg(II) and trivalent metal cations induced an hypsochromic shift of the absorption band and moderate emission enhancements. A highly selective response was obtained when using competitive media such as water- acetonitrile 95:5 v/v. In this case only Hg(II) induced a hypsochromic shift of the absorption band and a marked emission enhancement. The fifth chapter explores the development of sensors for berberine and amantadine; two molecules of biological interest due to their use as drugs. Three sensing systems based on a "molecular gate" approximation have been prepared. Specifically, MCM-41 nanoparticles were loaded with Rhodamine B as a signalling unit, functionalized with various amines and capped with cucurbituril CB7. The amines used are cyclohexylamine, benzylamine and amantadine., The materials obtained were characterized by X-ray diffraction techniques and transmission vi electron microscopy, confirming the mesoporous structure of the nanoparticles. The prepared materials showed a response to berberine and adamantine, which induced release of the fluorescent dye to the medium. The response of the materials to the two substances of interest (berberine and amantadine) depends on the chemical structure of the capping ensemble and it is a function of the affinity constants between the analyte and CB7. The results obtained open the way to the use of gated materials as berberine and amantadine probes.We thank the Spanish Government (MAT2015-64139-C4-1-R) and Generalitat Valenciana (PROMETEOII/2014/047). M. L. P. thanks Generalitat Valenciana for her Grisolia fellowship. Thanks are also due to Fundação para a Ciência e Tecnologia (Portugal) for financial support to the Portuguese NMR network (PTNMR, Bruker Avance III 400-Univ. Minho), FCT and FEDER (European Fund for Regional Development)-COMPETEQREN- EU for financial support to the research centre CQ/UM [PEst-C/ QUI/UI0686/2013 (FCOMP-01-0124-FEDER-037302)], and a post- doctoral grant to R. M. F. Batista (SFRH/BPD/79333/2011).Lo Presti, M. (2021). Optical detection of chemical species of environmental and biological relevance using molecular sensors and hybrid materials [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172664TESI
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