86,683 research outputs found
Innesti di futuro nella storia della città. Eugenio Miozzi e l’orizzonte della salvaguardia
No full textIl volume è esito della ricerca interdisciplinare condotta con l'obiettivo di indagare e valorizzare il fondo Eugenio Miozzi conservato presso l'Archivio Progetti dell'Università Iuav di Venezia.
Il saggio proposto approfondisce in particolare gli aspetti culturali, tecnici e operativi dell'attività dell'ingegnere dedicata a interventi di restauro e ammodernamento di importanti monumenti della città di Venezia, tra i quali il teatro La Fenice, il forte Sant'Andrea e numerosi campanili veneziani.
L'analisi della documentazione d'archivio, completamente inedita, riserva particolare attenzione alle relazioni tecniche e ai progetti esecutivi, e consente di tracciare la figura di un professionista dedicato a contrastare il decadimento della città lagunare con interventi sperimentali che incidono sulla scala territoriale e ambientale prima ancora che sul singolo edificio, consentendo di acquisire primi risultati e di aprire nuove traiettorie di ricerca sull’intensa opera di salvaguardia che Miozzi conduce dagli anni Trenta del Novecento fino alla sua scomparsa nel 1979
Aqueous concentration of CO2 in carbon-saturated fluids as a highly sensitive oxybarometer
No full textThe CO2 content of aqueous fluids in equilibrium with carbon can be used to retrieve their oxygen fugacity if pressure and temperature are known. Applicable to both natural and experimental systems, we present a new oxybarometer based on the aqueous concentration of CO2 in fluids saturated with either graphite or glass-like carbon, suitable to retrieve their oxygen fugacity. The method was experimentally tested by measuring by mass spectrometry the CO2 content in aqueous fluids coexisting with glass-like carbon buffered externally with Ni-NiO, employing ordered and disordered forms of NiO characterised by small differences in free energy (<5 kJ/mol). Considering analytical uncertainties on CO2 measurements, fO2 values can be resolved with an accuracy of about 0.01 log units, which is one order of magnitude lower than uncertainties affecting conventional solid state redox sensors. The CO2- in-fluid oxybarometer is the first available parameterisation of the fO2 dependency on pressure, temperature and CO2 content of aqueous fluids and can be used for fluids containing >1 mol. % CO2 beneath the graphite-diamond transition
Carbon-saturated COH fluids in the upper mantle: a review of high-pressure and high-temperature ex situ experiments
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Experimental assessment of wireless monitoring of axilla temperature by means of epidermal battery-less RFID sensors
No full textQuantitative analysis of COH fluids synthesized at HP–HT conditions: an optimized methodology to measure volatiles in experimental capsules
No full textThe quantitative assessment of COH fluids is crucial in modeling geological processes. The composition of fluids, and in particular their H2O/CO2 ratio, can influence the melting temperatures, the location of hydration or carbonation reactions, and the solute transport capability in several rock systems. In the scientific literature, COH fluids speciation has been generally assumed on the basis of thermodynamic calculations using equations of state of simple H2O–nonpolar gas systems (e.g., H2O–CO2–CH4). Only few authors dealt with the experimental determination of high-pressure COH fluid species at different conditions, using diverse experimental and analytical approaches (e.g., piston cylinder + capsule piercing + gas chromatography/mass spectrometry; cold seal + silica glass capsules + Raman). In this contribution, we present a new methodology for the synthesis and the analysis of COH fluids in experimental capsules, which allows the quantitative determination of volatiles in the fluid by means of a capsule-piercing device connected to a quadrupole mass spectrometer. COH fluids are synthesized starting from oxalic acid dihydrate at P = amb and T = 250°C in single capsules heated in a furnace, and at P = 1 GPa and T = 800°C using a piston-cylinder apparatus and the double-capsule technique to control the redox conditions employing the rhenium–rhenium oxide oxygen buffer. A quantitative analysis of H2O, CO2, CH4, CO, H2, O2, and N2 along with associated statistical errors is obtained by linear regression of the m/z data of the sample and of standard gas mixtures of known composition. The estimated uncertainties are typically <1% for H2O and CO2, and <5% for CO. Our results suggest that the COH fluid speciation is preserved during and after quench, as the experimental data closely mimic the thermodynamic model both in terms of bulk composition and fluid speciation
Interaction between river mouth flow and marine structures: numerical and experimental investigation
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