2,995 research outputs found
Le degré zero della carità. Eterogenesi di un sistema (Codogno, Settecento)
No full textThe article deals with a very peculiar system of charity, the one of community of Codogno in XVIIIth century. Within the community a multiplicity of pious legacies were based, that found their centre of control in the parish. The reforms of XVIIITh century partially changed the system, though the simplification of the structures was stemmed from a different canalization of economy and not from razionalization
Storia di una riscoperta. Il timorasso alle origini dell’enoturismo tortonese (dal 1980 a oggi)
No full textIl saggio ricostruisce la storia della riscoperta del timorasso nel Tortonese, connettendola allo sviluppo del territorio sul piano eno-turistico
La posizione occidentale verso l'Iran: containment e dialogo critico
No full textThe article analyses the Western policy towards the Islamic republic of Iran and the differences amongst the US policy (based on the dual containment) and the European one (critical dialogue). It states that these different approaches are not only a ‘carrot and stick’ policy but reflect a different perception and different goals in their policy toward Tehra
Realdo Colombo in the fifth centenary of his birth.
No full textThe date of birth of Realdo Colombo is still uncertain. However, 1516 is conventionally credited as the year where he was born in Cremona. Colombo’s life can be divided into three periods, according to the cities where he worked: Padua, Pisa and Rome. A talented anato-mist, in Padua Colombo became assistant of Andreas Vesalius in 1541. In 1545 he moved to Pisa at the behest of the Grand Duke Cosimo I de’ Medici. Finally, he was invited in Rome by Pope Paul III and became the physician of many important patients, including Michelangelo Buonarroti. He also performed the autopsy on the body of Saint Ignatius of Loyola. In his unique masterpiece, De re anatomica, consisting of 15 books, Colombo reported original observations. He hoped to have a text illustrated by Michelangelo that would have competed with the fabrica of Vesalius, but that purpose did not realize. Indeed, the unique engraving of the volume, published posthumously in 1559, is the frontispiece. The most important ana-tomical discovery attributed to Colombo is the original description of the pulmonary circula-tion, based on hundreds of dissections and vivisections. The Galen’s long-standing doctrine of the blood circulation from the right ventricle to the left ventricle through invisible pores of the interventricular septum was definitively rejected. Although two other figures had already described the pulmonary circulation – the thirteenth century Arabic physician Ibn al-Nafis, in the Commentary on Anatomy in Avicenna's Canon, and the Spanish philosopher Michael Servetus, in the theological book Christianismi restitutio – Colombo seems to have arrived at his conclusions independently. He also understood the function of the cardiac valves. Co-lombo’s book had a profound effect on William Harvey, when he prepared his lectures on anatomy for the College of Physicians of London, and was determinant for the publication of his description of the blood circulation in De motu cordis (1628). Other anatomical observa-tions are attributed to Colombo. He corrected previous misconceptions, demonstrating that the right kidney is lower than the left, and showing that the lens is in the anterior chamber of the eye. He recognized anatomical variants, such as the presence of palmaris longus, and described congenital malformations, such as the horseshoe kidney. He also seems to have coined the term “placenta” and claimed to have been the first to describe the clitoris and its function
Thermal properties of TPD-based organic glasses
No full textI vetri sono sistemi di materia condensata con proprietà fisiche intermedie tra quelle dei liquidi e quelle dei solidi. La loro struttura atomistica è determinata sia dalla loro storia termica sia dai metodi di preparazione. Da un punto di vista formale ciò corrisponde a un’iper-superficie di energia configurazionale di topologia molto complessa, caratterizzata da molti diversi bacini che differiscono per forma, estensione e profondità. Il sistema può essere intrappolato in ciascuno di essi, assumendo proprietà fisiche significativamente diverse. È stato dimostrato sperimentalmente che è possibile ottenere uno stato vetroso per deposizione di molecole organiche da fase vapore su un substrato solido. In questo caso la fisica del vetro risultante è ancora più complessa perché entrano in gioco fattori addizionali, quale ad esempio l’anisotropia della sottostante struttura molecolare. Abbiamo generato al computer un insieme di campioni di vetri organici costituiti da molecole TPD, mimando il processo di deposizione da fase vapore e ne abbiamo calcolato le proprietà termiche mediante tecniche di simulazione atomistica. In particolare, abbiamo elaborato un modello molto accurato capace (i) di spiegare le risultanze sperimentali indicanti un carattere fortemente anisotropo nella trasmissione di calore e (ii) di predire l’andamento in temperatura del calore specifico di questi vetri. In particolare, riportiamo nel regime quantistico di bassissime temperature l’evidenza di un’interessante anomalia rispetto ai sistemi cristallini.Glassy materials are condensed matter systems showing physical properties in between solids and liquids and retaining information about the thermal history they have been subjected to and the way they have been prepared. Formally, this implies that their configurational energy landscape is a complex multi-dimensional surface, showing quite a few basins with different depths, widths, and shapes: the system can be trapped in any of them, assuming very unlike physical properties. Recently, it has been demonstrated experimentally that a glassy system can be grown by physical vapor deposition of organic molecules on a substrate. The physics of such organic glasses is enriched by a new feature, namely: the anisotropic molecular structure of the basic building blocks used to assemble the film. TPD-based organic glasses have been generated by atomistic simulations that mimic vapor deposition and their thermal properties have been accordingly calculated. Simulations generate a rational phenomenology, providing robust evidence that heat transfer is not isotropic but, rather, correlated to an inherent molecular property, namely the axial structure of the TPD molecule. Furthermore, we present the first theoretical prediction of the specific heat trend versus temperature, showing in the quantum regime an intriguing anomaly with respect to crystalline systems
Model for thermal conductivity in nanoporous silicon from atomistic simulations
No full textBy means of molecular dynamics simulations, we have studied heat transport in nanoporous silicon, finding that the Eucken model, widely adopted in the description of thermal transport in macroporous systems, breaks down when pores are nanometer-sized. Present atomistic results are used to inform an extension to this model, effectively describing the relationship between thermal conductivity and interface density, here identified as the key structural characteristic of a porous sample. Our model, validated against a range of pore sizes and distributions, provides a robust framework for the interpretation of the atomistic results, as well as suggesting how to estimate the average pore size through thermal transport measurements
Orbit design for future SpaceChip swarm missions in a planetary atmosphere
No full textThe effect of solar radiation pressure and atmospheric drag on the orbital dynamics of satellites-on-a-chip (SpaceChips) is exploited to design equatorial long-lived orbits about the oblate Earth. The orbit energy gain due to asymmetric solar radiation pressure, considering the Earth's shadow, is used to balance the energy loss due to atmospheric drag. Future missions for a swarm of SpaceChips are proposed, where a number of small devices are released from a conventional spacecraft to perform spatially distributed measurements of the conditions in the ionosphere and exosphere. It is shown that the orbit lifetime can be extended and indeed selected through solar radiation pressure and the end-of-life re-entry of the swarm can be ensured, by exploiting atmospheric drag
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