3,707 research outputs found
Between Two Empires. Histoire des deux Indes And Modern Colonialism
No full textThe article critically analyses the late eighteenth century process of crisis and transformation of the concept of empire. By considering Raynal’s Histoire des deux Indes and the Enlightenment’s critique of the different imperial models, Pandolfi reconstructs the transit from classic colonialism – built around the relations between settlers, savages and slaves – to another phase characterized by the indirect exploitation of the labour force. The text underlines the ambivalence of Enlightenment towards the question of the empire by demonstrating how Raynal’s work reflects the constitutive tension of the second half of the 1700s. Therefore, through Diderot’s analysis, the author demonstrates how the moral advancement of humanity is the product of a constant interaction between the colonial rhetoric of commerce and those revolutions, which, – in different moments and places – have crossed the colonial space
Persiatherium rodleri, gen. et sp. nov. (Mammalia, Rhinocerotidae) from the upper Miocene of Maragheh (northwestern Iran)
No full textA new genus and species of Rhinocerotidae, Persiatherium rodleri, gen. et sp. Nov., a new acerathere rhinocerotid from the early upper Miocene (ca. 9 Ma) locality of Kopran, Maragheh (northwestern Iran), is described. The new taxon can be clearly distinguished from the three species previously reported at Maragheh: Iranotherium morgani, Ceratotherium neumayri, and Chilotherium persiae. Moreover, P. rodleri can be distinguished from the latest middle and late Miocene elasmotheres, teleoceratins, and rhinoceroses recorded in Eurasia and Africa. The new taxon displays morphological characters close to Aceratheriini. However, the presence of plesiomorphic characters on the teeth (presence of P1, continuous lingual cingula on the premolars, labial cingula on the premolars, lingual cingula on the molars, weak protocone constriction on the molars, absence of crista and antecrochet on the molars), of peculiar morphological characters (e.g., lingual side of the protoloph and metaloph directed disto-lingually on P2 with the presence of a lingual groove on the hypocone), as well as some derived characters (e.g., short metaloph on the molars), enable its distinction from other Aceratheriini. A cladistic analysis shows that P. rodleri is the sister taxon to Aceratherium huadeensis. Though the latter displays more derived features than P. rodleri, their phylogenetic relationships allow inclusion of both species in the same new genus
Diffusion-based degeneration of the collagen reinforcement in the pathologic human cornea
No full textWe describe a multiphysics model of the collagen structure of the cornea undergoing a progressive localized reduction of the stiffness, preluding to the development of ectasia and keratoconus. The architecture of the stromal collagen is assumed to follow the simplified two-family model proposed in Pandolfi et al. (A microstructural model of cross-link interaction between collagen fibrils in the human cornea. Philos Trans R Soc A 377:20180079, 2019), where the mechanical stiffness of the structure is supplied by transversal bonds within the fibrils of the same family (inter-crosslink bonds) and across the fibrils of the two families (intra-crosslink bonds). In Pandolfi et al. (A microstructural model of cross-link interaction between collagen fibrils in the human cornea. Philos Trans R Soc A 377:20180079, 2019), it was shown that the loss of the spherical shape due to the protrusion of a cone can be ascribed to the mechanical weakening of the intra-crosslink bonds in the central region of the collagen structure. In the present study, the reduction of bond stiffness is coupled to an evolutive pathologic phenomenon, modeled as a reaction–diffusion process of a normalized scalar field. We assume that the scalar field is a concentration-like measure of the degeneration of the chemical bonds stabilizing the structural collagen. We follow the evolution of the mechanical response of the system in terms of shape change, according to the propagation of the degeneration field, and identify the critical loss of mechanical stability resulting in the typical bulging of keratoconus corneas
Rhinocerotidae (Mammalia, Perissodactyla) from the middle pleistocene site of ponte milvio, central Italy
No full textThree rhinoceros species have been identified at Ponte Milvio: Stephanorhinus hundsheimensis (Toula, 1902), Stephanorhinus hemitoechus (Falconer, 1859) and Stephanorhinus kirchbergensis (Jäger, 1839). Remains ascribed to S. hundsheimensis were collected in gravels and sands deposits. They show morphological and morphometric affinities with the small-sized populations of the latest Early Pleistocene from Vallonnet. The occurrence of these small-sized specimens suggests the presence of a faunal assemblage chronologically related with the Early-Middle Pleistocene transition. The remains of S. hemitoechus and S. kirchbergensis were collected in volcanoclastic deposits. The specimens ascribed to S. hemitoechus show morphometric characters close to the small-sized specimens of the latest Middle Pleistocene. Moreover, S. kirchbergensis seems to be common in Italy during the late Middle Pleistocene and it has never been collected with certainty from Late Pleistocene sites. The co-occurrence of S. kirchbergensis and the small-sized S. hemitoechus suggests the presence of a faunal assemblage chronologically referable to a time span between MIS10 and MIS8
Applications of a micro-structured brittle damage model to laboratory tests on rocks
No full textA multiscale microstructured brittle damage model is used to describe the behavior of confined rock materials. Plane strain and triaxial tests conducted
at the laboratory scale are simulated in terms of boundary value problems. Simulations reveal good predictive qualities of the model to describe the macroscopic features of specimens at failure. The microstructures, oriented in different directions, allow the localization of the macroscopic strain along straight lines, emerging at the macroscale in the form of shear bands. The microstructured material model, characterized by recursive equidistant parallel cohesive-frictional faults, is fully defined by six elastic and inelastic material constants. The model was originally developed in a finite kinematics framework to simulate the dynamic behavior of confined brittle materials (Pandolfi et al. in J
Mech Phys Solids 54:1972–2003, 2006). In linearized form, it has been extended and used for the simulation of in-field excavations (De Bellis et al. in: Eng
Geol 215:10–24, 2016). The performance of the model in predicting the behavior of small scale rock tests in the laboratory, the object of the present study, has
never been investigated. Numerical simulations show that the model is able to capture several important features observed in rocks, in particular the reduction
of the overall stiffness for increasing deterioration of the material, fragile to ductile transition, strain localization, shear band formation, and more general size effect
Pandolfi, Girolamo
No full textDefinire Pandolfi poeta o umanista o antiquario significa fermarsi a una parte della sua attività, dimenticando l’impegno che lo assorbì negli anni migliori, cioè il commercio di opere d'arte italiane nel primo squarcio del Cinquecento. Fu un tramite importantissimo fra le corti padane e Firenze.
In lui emergono i tratti inconfutabili di un innovatore nel gusto artistico, che finì per imporre le sue scelte presso i committenti più prestigiosi
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