91,142 research outputs found
Lorenzo Milani in our times
Get PDFThis article pays tribute to one of Europe's foremost critical pedagogues, the Tuscan Don Lorenzo Milani, on the ninetieth anniversary of his birth. It highlights the key moments in his life as priest and educator as well as his pedagogical approach directed at challenging the class-conditioned status quo in Italian society and at achieving greater social justice. His was a pedagogy which highlighted the collective dimensions of learning and teaching, pupils being students and educators at the same time, an approach to learning akin to what Paulo Freire would call critical literacy and what contemporary writers would call critical media literacy in the sense of reading and writing the word and the world. His pedagogy entailed a process of reading history against the grain as part of an attempt to generate a culture of non-militarization. All these elements make Don Milani and his student-teachers pedagogues for our times.peer-reviewe
Effective closed form starting point determination for kinetic model interpreting NR vulcanized with sulphur
Get PDFIn this paper, a closed form analytical approach for a recently presented kinetic model proposed in Milani and Milani (Polym Test, 2013, under review) to interpret NR sulphur vulcanization in presence of either experimental or surrogate rheometer curves is proposed. The model has kinetic base and is aimed at predicting, by means of a very refined approach, the vulcanization degree of NR vulcanized with sulphur. It needs as input only rheometer curves to fit and provides as output kinetic constants of the single reactions occurring during the crosslink process. In Milani and Milani (Polym Test, 2013, under review) a cure chemical scheme constituted by five reactions occurring in series and parallel was adopted. The chemical scheme, translated mathematically into a differential equations system, was suitably re-arranged and a single analytical equation was derived, representing rubber crosslink degree evolution upon time. The main drawback of such procedure is that the five kinetic constants corresponding to each reaction were determined through a standard non-linear least squares procedure, trying to minimize the deviation of the analytical cure curve from experimental data. Such a limitation is here superseded and a major improvement is proposed utilizing (1) a closed form solution which does not require any optimization algorithm and (2) finding analytically a starting point for the unknown kinetic constants, very near to the actual solution and thus very convenient for a successive least squares minimization. In the model, it is shown how the analytical condition deduced from the scorch point (second derivative of the rheometer curve equal to zero) and two further conditions, e. g. the time at 90% of vulcanization and the reversion percentage, allow the simple direct evaluation of kinetic constants, providing a closed form analytical formula to predict well the state of cure of the rubber under consideration. To assess the results obtained with the model proposed, several examples on two different NRs are discussed. The approach proved to be extremely robust and much faster when compared with the model proposed by Milani and Milani (Polym Test, 2013, under review)
Italian signposts for a sociologically and critically engaged pedagogy : Don Lorenzo Milani (1923-1967) and the schools of San Donato and Barbiana revisited
Get PDFThis paper provides a critical exposition and analysis of the work of an acclaimed Italian educator, Lorenzo Milani, and ideas that emerged from his experiences in two Tuscan localities. His work is well known in Italy and many parts of southern Europe. Despite the translations of his works into English and Spanish, in the early 1970s, and their use in sociology of education classes in the United Kingdom, he seems to have had a very limited impact on the Anglo-North American-dominated critical education field. The paper revisits his ideas, in this 90th anniversary year, indicating their contemporary relevance and the signposts they provide for a critically and sociologically engaged pedagogy.peer-reviewe
Iterative robust numerical procedure for the determination of kinetic constants in Han’s model for NR cured with sulphur
Get PDFA closed form procedure to determine kinetic constants for NR vulcanized with sulphur is presented. The kinetic scheme originally proposed by Han et al. (Polymer (Korea) 22:223–230, 1998) and further modified by Milani et al. (Polym Test 32:1052–1063, 2013) is adopted as starting point to deduce a closed form expression for rubber curing degree. Rheometer experimental data collected at different temperatures are used to tune model parameters. After the normalization of the rheometer curves and the exclusion of induction period from calculations, the model requires the estimation of three kinetic constants, two of them describing incipient curing and stable crosslinks formations, the last reproducing reversion phenomenon. Whilst such constants are almost always determined by least-squares best fitting, here a numerical iterative procedure—much more stable and efficient from a computational standpoint—is proposed. The approach requires as input parameters only the degree of vulcanization at infinite (i.e. at the end of vulcanization), the instant where the maximum torque is reached and initial rate of vulcanization. The condition that the numerical curve reaches a maximum at a given time translates mathematically into a non-linear equation in two of the kinetic constants, which are determined iteratively in the paper. The numerical initial vulcanization rate is tuned in such a way to globally minimize the absolute error between numerical and experimental curves. The main capability of the procedure proposed stands in the very straightforward determination of reaction kinetic constants, avoiding demanding least-squares fittings on rheometer experimental data. A set of experimental data available, relying into rheometer curves of the same rubber blend conducted at five different temperatures are used to estimate the fitting capabilities of the mathematical model proposed. Very good agreement with experimental data is observed
GURU v2.0: An interactive Graphical User interface to fit rheometer curves in Han's model for rubber vulcanization
Get PDFA GUI software (GURU) for experimental data fitting of rheometer curves in Natural Rubber (NR) vulcanized with sulphur at different curing temperatures is presented. Experimental data are automatically loaded in GURU from an Excel spreadsheet coming from the output of the experimental machine (moving die rheometer). To fit the experimental data, the general reaction scheme proposed by Han and co-workers for NR vulcanized with sulphur is considered. From the simplified kinetic scheme adopted, a closed form solution can be found for the crosslink density, with the only limitation that the induction period is excluded from computations. Three kinetic constants must be determined in such a way to minimize the absolute error between normalized experimental data and numerical prediction. Usually, this result is achieved by means of standard least-squares data fitting. On the contrary, GURU works interactively by means of a Graphical User Interface (GUI) to minimize the error and allows an interactive calibration of the kinetic constants by means of sliders. A simple mouse click on the sliders allows the assignment of a value for each kinetic constant and a visual comparison between numerical and experimental curves. Users will thus find optimal values of the constants by means of a classic trial and error strategy. An experimental case of technical relevance is shown as benchmark
The Hera Milani Mission
Get PDFHera is the European part of the Asteroid Impact & Deflection Assessment (AIDA) international collaboration with NASA who is responsible for the DART (Double Asteroid Redirection Test) kinetic impactor spacecraft. Hera will be launched in October 2024 and will arrive late 2026. The Hera mothercraft will accommodate two 6U CubeSat, one of which is Milani, named after Professor Andrea Milani, for his unique contribution to asteroid science and visionary role in defining a viable planetary defence technique. The Milani CubeSat is developed by Tyvak International leading a consortium of European Universities, Research Centers and Firms from Italy, Czech Republic, Finland. During the cruise to the Asteroid (+2 years), Milani CubeSat will be hosted inside the Hera mothercraft, periodically checked for health and charged. At arrival it will be deployed and commissioned while Hera is performing the Dydymos detailed characterization phase, at about 10 to 20 km distance from the asteroid. Milani mission objectives are defined to add scientific value to the Hera mission: i) Map the global asteroid composition, ii) Characterize the asteroid surface, iii) Evaluate DART impacts effects on asteroid and support gravity field determination, iv) Characterize dust clouds around the asteroid, enhancing the scientific return of the whole Hera mission. The instruments supporting the mission are “ASPECT” (VTT, Finland), a SWIR, NIR and VIS imaging spectrometer and the “VISTA” (INAF, Italy), a thermogravimeter characterizing dust particles below 10μm
Milani Lorenzo
No full textViene messo in evidenza il contributo di Lorenzo Milani alla riflessione sulla persona nel nesso tra dimensione della coscienza istanze etiche di coinvolgimento attivo (I care)
Luce e pathos nella narrativa di Daniele Del Giudice
No full textLa pubblicazione nel 2016 del volume che contiene tutti i racconti di Daniele Del Giudice consente non solo di recuperare testi introvabili ma di osservare nell’insieme la coerenza della narrativa breve di uno scrittore che ha sempre affrontato con lucidità l’evanescenza della trama e la tentazione al silenzio della parola scritta. Infatti proprio nei racconti è possibile individuare il fondamento di una scrittura che gioca sul filo dell’indicibile, oscillando tra un’estrema sensibilità percettiva e un’oggettivazione del dato reale. In questo senso, la prosa cristallina e oggettivante di Del Giudice si presta particolarmente a un’indagine sulla rappresentazione delle emozioni nella letteratura italiana contemporanea, perché nasconde una minuziosa capacità nell’osservazione dei mutamenti emotivi dell’individuo in relazione all’instabilità delle relazioni umane e alla consapevolezza dell’infinitesimale e inafferrabile complessità della materia vivente, spesso attraverso il correlativo offerto dallo sguardo e dagli effetti prodotti dalla luce
Lorenzo Milani (1923-1967)
No full textIl contributo ripercorre dal punto di vista storico-educativo la biografia di don Lorenzo Milani, mettendo in luce i fondamenti della "pedagogia della parola" e il rapporto tra istruzione ed emancipazione sociale
Un “outsider” mediatore tra due culture
No full textIl saggio delinea il profilo dello scrittore bolognese Giuseppe Raimondi, in occasione della mostra di documenti originali presenti nel Fondo d'archivio dell'autore conservato presso la Biblioteca umanistica "E. Raimondi" del Dipartimento FICLIT dell'Università di Bologna, allestita presso gli spazi della biblioteca comuna dell'Archiginnasio di Bologna, novembre 2022-febbraio 2023
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