Un paneretto d’insalatella in rime e in prose: il novelliere senese attribuito a Gentile Sermini

Sebbene il testo sia molto interessante – linguisticamente e folcloristicamente prezioso, letterariamente ricco e complesso – per almeno due secoli, dal momento della sua “riscoperta” sino ai giorni nostri, esso è stato bistrattato, relegato ai margini della letteratura popolare o di imitazione boccaccesca e, infine, liquidato frettolosamente perché giudicato carente di interessi letterari o artistici. Uno dei suoi critici più intransigenti, Letterio Di Francia, giudica la raccolta «un libro disordinato, povero di vita, monotono nella scelta dei temi e nella rappresentazione dei personaggi, riboccante di oscenità e nello stesso tempo di inverosimiglianze, di esagerazioni, di lungaggini». Le quaranta novelle hanno sofferto nel tempo di un atteggiamento idiosincratico da parte della critica che ha focalizzato la sua attenzione esclusivamente sugli aspetti più smaccatamente lascivi delle storie, e dietro a questo giudizio si è barricata per valutare, principalmente dal punto di vista morale, sia il testo che il suo autore. Così sempre Di Francia scrive che la «penna sciagurata » di Sermini non era in grado di mettere un po’ d’anima o di sentimento nei suoi personaggi, «nelle loro turpi azioni, non si trova mai altro movente, che non sia quello di un malsano egoismo, o dell’istinto perverso, o del pervertimento bestiale dei sensi».A partire dalla fine del Settecento, sino ai giorni nostri, una raccolta quattrocentesca di quaranta novelle, trentasei liriche e tre prose di altro genere è stata tramandata con il titolo di Novelle e attribuita al non meglio specificato senese Gentile Sermini

The effects of MgO, Na2O and SO3 on industrial clinkering process: phase composition, polymorphism, microstructure and hydration, using a multidisciplinary approach

Preprint publicado en: Materials Characterization Volume 155, September 2019, 109809The present investigation deals with how minor elements (their oxides: MgO, Na2O and SO3) in industrial kiln feeds affect (i) chemical reactions upon clinkering, (ii) resulting phase composition and microstructure of clinker, (iii) hydration process during cement production. Our results show that all these points are remarkably sensitive to the combination and interference effects between the minor chemical species mentioned above. Upon clinkering, all the industrial raw meals here used exhibit the same formation temperature and amount of liquid phase. Minor elements are preferentially hosted by secondary phases, such as periclase. Conversely, the growth rate of the main clinker phases (alite and belite) is significantly affected by the nature and combination of minor oxides. MgO and Na2O give a very fast C3S formation rate at T > 1450 K, whereas Na2O and SO3 boost C2S After heating, if SO3 occurs in combination with MgO and/or Na2O, it does not inihibit the C3S crystallisation as expected. Rather, it promotes the stabilisation of M1-C3S, thus indirectly influencing the aluminate content, too. MgO increseases the C3S amount and promotes the stabilisation of M3-C3S, when it is in combination with Na2O. Na2O seems to be mainly hosted by calcium aluminate structure, but it does not induce the stabilisation of the orhtorhombic polymorph, as supposed to occur. Such features play a key role in predicting the physicalmechanical performance of a final cement (i.e. rate of hydration and hardening) when used as a bulding material.The present study has been partly funded by the project PRIN 2017 (2017L83S77), of the Italian Ministry for Education, University and Research (MIUR)

Abitare i conflitti socio-ambientali

Il percorso parte dalla definizione di conflitto socio-ambientale visto come momento particolare di confronto tra diversi progetti alternativi di uso del territorio e delle risorse ponendo attenzione al vocabolario usato nell\u2019analisi e nella gestione. La tappa successiva presenta alcuni aspetti da mettere a fuoco per osservare e posizionarsi in un conflitto socio-ambientale: l\u2019evoluzione attraverso le fasi di latenza, visibilit\ue0 e (in alcuni casi) trasformazione; la mappatura dinamica degli attori coinvolti in un conflitto socio-ambientale, le questioni ambientali oggetto di disputa. Il lavoro propone poi alcune indicazioni operative su come abitare i conflitti socio-ambientali nella prevenzione e gestione dei conflitti che potrebbero integrare la pratica professionale di chi opera nel territorio. Infine uno sguardo retrospettivo e prospettivo alla luce delle esperienze in America Latina su protagonismo nei conflitti socio.ambientali in contesti di depredazione dei territori

INCREASING THE DIMENSIONAL STABILITY OF CAO-FEOX-AL2O3-SIO2 ALKALI-ACTIVATED MATERIALS: ON THE SWELLING POTENTIAL OF CALCIUM OXIDE-RICH ADMIXTURES

Advanced thermochemical conversion processes are emerging technologies for materials\u2019 recovery and energetic conversion of wastes. During these processes, a (semi-)vitreous material is also produced, and as these technologies get closer to maturity and full-scale implementation, significant volumes of these secondary outputs are expected to be generated. The production of building materials through the alkali activation of such residues is often identified as a possible large-scale valorization route, but the high susceptibility of alkali-activated materials (AAM) to shrinkage limits their attractiveness to the construction sector. Aiming to mitigate such a phenomenon, an experimental study was conducted investigating the effect of calcium oxide-rich admixtures on the dimensional stability of CaO-FeOx-Al2O3-SiO2 AAMs. This work describes the impacts of such admixtures on autogenous and drying shrinkage, porosity, microstructure, and mineralogy on AAMs. Drying shrinkage was identified as the governing mechanism affecting AAM volumetric stability, whereas autogenous shrinkage was less significant. The reference pastes presented the highest drying shrinkage, while increasing the dosage of shrinkage reducing agent (SRA) was found to reduce drying shrinkage up to 63%. The reduction of drying shrinkage was proportional to SRA content; however, elevated dosages of such admixture were found to be detrimental for AAM microstructure. On the other hand, small dosages of calcium oxide-rich admixtures did not induce significant changes in the samples\u2019 mineralogical evolution but promoted the formation of denser and less fractured microstructures. The results presented here show that calcium oxide-rich admixtures can be used to increase AAM\u2019s volumetric stability and an optimal dosage is prescribed

HST/ACS Photometry of Old Stars in NGC 1569: The Star Formation History of a Nearby Starburst

(abridged) We used HST/ACS to obtain deep V- and I-band images of NGC 1569, one of the closest and strongest starburst galaxies in the Universe. These data allowed us to study the underlying old stellar population, aimed at understanding NGC 1569's evolution over a full Hubble time. We focus on the less-crowded outer region of the galaxy, for which the color-magnitude diagram (CMD) shows predominantly a red giant branch (RGB) that reaches down to the red clump/horizontal branch feature (RC/HB). A simple stellar population analysis gives clear evidence for a more complicated star formation history (SFH) in the outer region. We derive the full SFH using a newly developed code, SFHMATRIX, which fits the CMD Hess diagram by solving a non-negative least squares problem. Our analysis shows that the relative brightnesses of the RGB tip and RC/HB, along with the curvature and color of the RGB, provide enough information to ameliorate the age-metallicity-extinction degeneracy. The distance/reddening combination that best fits the data is E(B-V) = 0.58 +/- 0.03 and D = 3.06 +/- 0.18 Mpc. Star formation began ~ 13 Gyr ago, and this accounts for the majority of the mass in the outer region. However, the initial burst was followed by a relatively low, but constant, rate of star formation until ~ 0.5-0.7 Gyr ago when there may have been a short, low intensity burst of star formation.Comment: 50 pages, including 17 figures. Accepted for publication in A

Hubble Tarantula Treasury Project - VI. Identification of Pre-Main-Sequence Stars using Machine Learning techniques

The Hubble Tarantula Treasury Project (HTTP) has provided an unprecedented photometric coverage of the entire star-burst region of 30 Doradus down to the half Solar mass limit. We use the deep stellar catalogue of HTTP to identify all the pre--main-sequence (PMS) stars of the region, i.e., stars that have not started their lives on the main-sequence yet. The photometric distinction of these stars from the more evolved populations is not a trivial task due to several factors that alter their colour-magnitude diagram positions. The identification of PMS stars requires, thus, sophisticated statistical methods. We employ Machine Learning Classification techniques on the HTTP survey of more than 800,000 sources to identify the PMS stellar content of the observed field. Our methodology consists of 1) carefully selecting the most probable low-mass PMS stellar population of the star-forming cluster NGC 2070, 2) using this sample to train classification algorithms to build a predictive model for PMS stars, and 3) applying this model in order to identify the most probable PMS content across the entire Tarantula Nebula. We employ Decision Tree, Random Forest and Support Vector Machine classifiers to categorise the stars as PMS and Non-PMS. The Random Forest and Support Vector Machine provided the most accurate models, predicting about 20,000 sources with a candidateship probability higher than 50 percent, and almost 10,000 PMS candidates with a probability higher than 95 percent. This is the richest and most accurate photometric catalogue of extragalactic PMS candidates across the extent of a whole star-forming complex.Comment: 26 pages, 25 figures, Accepted for publication in MNRA