Misure di temperatura tramite radiazione infrarossa

Ad oggi, grazie al progresso tecnologico, sono stati realizzati accuratissimi rivelatori di radiazione infrarossa, rendendo possibili misure altamente precise. L’impiego massiccio dell’indagine termografica infrarossa è basato sull’emissione termica da parte della materia. Tutta la materia a temperatura superiore dello zero assoluto emette radiazione elettromagnetica con una certa distribuzione spettrale, dipendente dalla temperatura e dalle caratteristiche costitutive. Le capacità emissive di un corpo sono quantificate da un parametro, l’emissività, che confronta i corpi reali con il corpo nero, modellizzazione matematica di un perfetto emettitore. I corpi a temperatura ambiente emettono principalmente nell’infrarosso. Poichè la radiazione infrarossa non è percepibile dall’occhio umano, i corpi a temperature ordinarie non appaiono luminosi e sono visti brillare unicamente di luce riflessa. Solo fornendo calore al sistema, aumentandone cioè la temperatura, l’emissione di picco si sposta verso le frequenze del visibile ed i corpi appaiono luminosi; si pensi ad esempio alle braci della legna bruciata. La possibilità di rivelare la radiazione infrarossa con opportuni dispositivi permette quindi di vedere la “luce” emessa da corpi relativamente freddi. Per questo motivo la termografia trova applicazione nella visione o videoregistrazione notturna o in condizioni di scarsa visibilità. Poichè la distribuzione spettrale dipende dalla temperatura, oltre al picco di emissione anche la quantità di radiazione emessa dipende dalla teperatura, in particolare è proporzionale alla quarta potenza della temperatura. Rilevando la quantità di radiazione emessa da un corpo se ne può dunque misurare la temperatura superficiale, o globale se il corpo è in equilibrio termico. La termometria, ovvero la misura della temperatura dei corpi, può dunque sfruttare la termografia per operare misure a distanza o non invasive

Alle origini del principato cosimiano: il ruolo dei segreatri attraverso l'analisi e la descrizione dei documeti dell'Archivio Mediceo del principato (1542-1559)

La ricerca si inserisce nell'ambito del seminario "Le grandi serie epistolari dell'Archivio Mediceo del principato nell'epoca di Cosimo I" organizzato dal Dott. Martelli e dalla Prof. ssa Toccafondi per gli studenti del biennio 2005/2007 della Scuola di archivistica, paleografia e diplomatica "Maria Agnoletti" dell'Archivio di Stato di Firenze. Nella prima parte della ricerca ho ricostruito in modo approfondito e puntuale, attarverso un'ampia bibliografia in italiano, francese e inglese e sopparttutto attraverso l'analisi diretta della documentazione conservata presso l'Archivio di Stato Firenze, il passaggio, cruciale per la storia fiorentina, dalla repubblica al principato e l'opera del primo granduca Cosimo I mettendone in evidenza i tre momenti cruciali che ne hanno segnato l'ascesa - la restuzione delle fortezze, la conquista di Siena e il conferimento da parte di Pio V del titolo granducale. Ho poi delineato l'organizzazione della segreteria medicea durante il principato di Cosimo I e le competenze dei segretari che operano a piu' stretto contatto con la persona del Duca - Francesco Campana, Lelio Torelli, Bartolomeo Concini, Lorenzo e Cristiano Pagni, Bernardo Giusti, Iacopo Guidi, Ugolino Grifoni, Pierfrancesco Riccio e Francesco Babbi - attraverso l'analisi della documentazione conservata nell'Archivio Mediceo del principato e in particolare delle unita' archivistiche con numero di Inventario Sommario dal 184 al 207 per i "Registri di lettere"; dal n. 205 al 208 per le "Minute di lettere"; da 356 al 365 per il "Carteggio Universale" e dal 1171 al 1176/b per il "Carteggio dei segretari". Nella seconda parte ho proceduto ad elaborare delle descrizioni archivistiche del materiale documetario dei "Registri di lettere" e "Minute di lettere" a livello di fondo, serie, unita' attraverso l'utilizzo degli standard internazionali ISAD (G) - General International Standard Archival Description - e del soggetto produttore attraverso l'utillizzo dello standard ISAD (CPF) - International Standard Archival Description for Corporate Body, Person and Family. In appendice ho trascritto integralmente alcuni documenti particolarmete significativi che ho utilizzato per la ricostruzione storica e ho riporato le riproduzioni di missive di mano dei segretari oggetto della ricerca che mi sono servite per l'analisi paleografica e l'identificazione delle scritture dei segretari minutanti

Evidence for a role of Arabidopsis CDT1 proteins in gametophyte development and maintenance of genome integrity

Meristems retain the ability to divide throughout the life cycle of plants, which can last for over 1000 years in some species. Furthermore, the germline is not laid down early during embryogenesis but originates from the meristematic cells relatively late during development. Thus, accurate cell cycle regulation is of utmost importance to avoid the accumulation of mutations during vegetative growth and reproduction. The Arabidopsis thaliana genome encodes two homologs of the replication licensing factor CDC10 Target1 (CDT1), and overexpression of CDT1a stimulates DNA replication. Here, we have investigated the respective functions of Arabidopsis CDT1a and CDT1b. We show that CDT1 proteins have partially redundant functions during gametophyte development and are required for the maintenance of genome integrity. Furthermore, CDT1-RNAi plants show endogenous DNA stress, are more tolerant than the wild type to DNA-damaging agents, and show constitutive induction of genes involved in DNA repair. This DNA stress response may be a direct consequence of reduced CDT1 accumulation on DNA repair or may relate to the ability of CDT1 proteins to form complexes with DNA polymerase e, which functions in DNA replication and in DNA stress checkpoint activation. Taken together, our results provide evidence for a crucial role of Arabidopsis CDT1 proteins in genome stability

Oesophageal perforation: an unexpected complication during extraction of a pacing lead. A case report.

Background: Peri-procedural transoesophageal echocardiography (TOE) is important in monitoring and minimizing major complications during pacing lead extraction. It is a widely accepted precautionary measure, especially in extractions considered to be higher risk. Pacing lead extraction may be challenging, and it is associated with significant risk of major bleeding from vascular trauma. Case summary: We present a case of an 87-year-old woman who had an extraction of a ventricular pacing lead that had perforated to an extra-cardiac location, most likely to the left pleural space. Peri-procedural TOE was used as a precaution. The entire pacing lead was successfully extracted with gentle traction using standard equipment (mechanical technique). Extraction was followed by development of pneumomediastinum and a left pleural effusion, initially attributed to pulmonary injury from the pacing lead but which proved to be related to oesophageal injury from the TOE. Discussion: Transoesophageal echocardiography-related complications are uncommon but should be considered in cases of unexpected post-procedural deterioration. Clinical deterioration after a seemingly uneventful procedure should prompt a thorough case review. A systematic approach should be applied to identify the offending cause and enable corrective measures to be undertaken. This case report is an important reminder to all operators utilizing TOE for peri-procedural purposes that this precautionary measure itself also independently exposes the patient to additional risk

The functionalization of nanodiamonds (diamondoids) as a key parameter of their easily controlled self-assembly in micro- and nanocrystals from the vapor phase

We detail herein readily accessible processes to control previously unobserved robust self-assemblies of nanodiamonds (diamondoids) in micro- and nanocrystals from their mild vapor deposition. The chemical functionalization of uniform and discernible nanodiamonds was found to be a key parameter, and depending on the type of functional group (hydroxy, fluorine, etc.) and its position on the diamondoid, the structure of the discrete deposits can vary dramatically. Thus, well-defined anisotropic structures such as rod, needle, triangle or truncated octahedron shapes can be obtained, and self-assembled edifices of sizes ranging from 20 nm to several hundred micrometers formed with conservation of a similar structure for a given diamondoid. Key thermodynamic data including sublimation enthalpy of diamondoid derivatives are reported, and the SEM of the self-assemblies coupled with EDX analyses and XRD attest the nature and purity of nanodiamond crystal deposits. This attractive method is simple and outperforms in terms of deposit quality dip-coating methods we used. This vapor phase deposition approach is expected to allow for an easy formation of diamondoid nanoobjects on different types of substrates

Social capital in contemporary society : decline or change

This theoretical thesis is going to explore social capital and its relation with trust, civic engagement, and leisure to better understand the complexity of social capital. Some of the concerns advanced by scholars stating that there is a decline of social capital in contemporary society are challenged. Controversies regarding theoretical and methodological applications, and a review of how special interests might have been used to promote particular causes affecting intervention and division of resources, are going to be examined. The intent is to show that there are alternative explanations for changes that do not pertain or predict decline. A discussion of the political and social ramifications of social capital and implications for future research and policy are going to conclude this analysis

Cation distribution in manganese cobaltite spinels Co3−xMnxO4 (0 ≤ x ≤ 1) determined by thermal analysis

Thermogravimetric analysis was used in order to study the reduction in air of submicronic powders of Co3−x Mn x O4 spinels, with 0 ≤ x ≤ 1. For x = 0 (i.e. Co3O4), cation reduction occurred in a single step. It involved the CoIII ions at the octahedral sites, which were reduced to Co2+ on producing CoO. For 0 < x ≤ 1, the reduction occurred in two stages at increasing temperature with increasing amounts of manganese. The first step corresponded to the reduction of octahedral CoIII ions and the second was attributed to the reduction of octahedral Mn4+ ions to Mn3+. From the individual weight losses and the electrical neutrality of the lattice, the CoIII and Mn4+ ion concentrations were calculated. The distribution of cobalt and manganese ions present on each crystallographic site of the spinel was determined. In contrast to most previous studies that took into account either CoIII and Mn3+ or Co2+, CoIII and Mn4+ only, our thermal analysis study showed that Co2+/CoIII and Mn3+/Mn4+ pairs occupy the octahedral sites. These results were used to explain the resistivity measurements carried out on dense ceramics prepared from our powders sintered at low temperature (700–750 °C) in a Spark Plasma Sintering apparatus

Left Ventricular Fluid Mechanics: the long way from theoretical models to clinical applications

\u2014The flow inside the left ventricle is characterized by the formation of vortices that smoothly accompany blood from the mitral inlet to the aortic outlet. Computational fluid dynamics permitted to shed some light on the fundamental processes involved with vortex motion. More recently, patient-specific numerical simulations are becoming an increasingly feasible tool that can be integrated with the developing imaging technologies. The existing computational methods are reviewed in the perspective of their potential role as a novel aid for advanced clinical analysis. The current results obtained by simulation methods either alone or in combination with medical imaging are summarized. Open problems are highlighted and perspective clinical applications are discussed

Fluid Structure Interaction of Multiple Flapping Filaments Using Lattice Boltzmann and Immersed Boundary Methods

The problem of flapping filaments in an uniform incoming flow is tackled using a Lattice Boltzmann—Immersed Boundary method. The fluid momentum equations are solved on a Cartesian uniform lattice while the beating filaments are tracked through a series of markers, whose dynamics are functions of the forces exerted by the fluid, the filament flexural rigidity and the tension. The instantaneous wall conditions on the filament are imposed via a system of singular body forces, consistently discretised on the lattice of the Boltzmann equation. We first consider the case of a single beating filament, and then the case of multiple beating filaments in a side-by-side configuration, focussing on the modal behaviour of the whole dynamical systems