5,768 research outputs found
Architettura una Risorsa per Modernizzazione Convegni Convegno dell’Istituto Nazionale di Architettura, Roma, Auditorium della Confindustria, Gennaio 2000
No full textUn convegno internazionale organizzato dall'InArch con la conduzione scientifica di Antonino Saggio insieme a Massimo Locci, Luigi Prestinenza e M.assimo Bilò
Theoretical assessment of thermodynamic stability in nanocrystalline metallic alloys
No full textThermal stability in nanocrystalline alloys has been extensively explored while using both experimental and theoretical approaches. From the theoretical point of view, the vast majority of the models proposed in the literature have been implicitly limited to immiscible or dilute systems and thus lack the necessary generality to make predictions for different alloying interactions and in the case of intermetallic compounds formation. In this work, a general theoretical description for the case of binary W-based alloys is presented. It is shown that a critical value Ω∗ of the interaction energy in the grain boundary Ω(gb) exists, such that the condition Ω(gb
Arlotti-Beccu-Desideri-Raimondo (by Massimo Locci)
No full textCurrently one of the most active offices in Rome, ABDR has seven major projects under way or at the point of completion. Massimo Locci explain the practice's work in its combination of a purist Modernist language aptitude for expressive informality
Probing proteins in solution by 129Xe NMR spectroscopy
No full textThe interaction of xenon with different proteins in aqueous solution is investigated by (129)Xe NMR spectroscopy. Chemical shifts are measured in horse metmyoglobin, hen egg white lysozyme, and horse cytochrome c solutions as a function of xenon concentration. In these systems, xenon is in fast exchange between all possible environments. The results suggest that nonspecific interactions exist between xenon and the protein exteriors and the data are analyzed in term of parameters which characterize the protein surfaces. The experimental data for horse metmyoglobin are interpreted using a model in which xenon forms a 1:1 complex with the protein and the chemical shift of the complexed xenon is reported (Locci et al. Keystone Symposia "Frontiers of NMR in Molecular Biology VI", Jan. 9--15, 1999, Breckenridge, CO, Abstract E216, p. 53; Locci et al. XeMAT 2000 "Optical Polarization and Xenon NMR of Materials", June 28--30, 2000, Sestri Levante, Italy, p. 46).SCOPUS: ar.jinfo:eu-repo/semantics/publishe
A text classification framework based on optimized error correcting output code
No full textIn recent years, there has been increasing interest in using text classifiers for retrieving and filtering infomation from web sources. As the numbers of categories in this kind of software applications can be high, Error correcting Output Coding (ECOC) can be a valid approach to perform multi-class classification. This paper explores the use of ECOC for learning text classifiers using two kinds of dichotomizers and compares them to each corresponding monolithic classifier. We propose a simulated annealing approach to calculate the coding matrix using an energy function similar to the electrostatic potential energy of a system of charges, which allows to maximize the average distance between codewords |with low variance. In addition, we use a new criterion for selecting features, a feature (in this specific context) being any term that may occur in a document. This criterion defines a measure of discriminant capability and allows to order terms according to it. Three different measures have been experimented to perform feature ranking/selection, in a comparative setting. Experimental results show that reducing the set of features used to train classifiers does not affect classification performance. Notably, feature selection is not a preprocessing activity valid for all dichotomizers. In fact, features are selected for each dichotomizer that occurs in the matrix coding, typically giving rise to a different subset of features depending on the dichotomizers at hand
Diel changes in water chemistry in the Baccu Locci stream (Sardinia, Italy) affected by past mining
No full textDiel variations in dissolved As and Zn concentrations in the Baccu Locci stream (sardinia,
Italy), affected by past mining, were studied. sorption/desorption to/from streambed material, in particular
ferrihydrite, is believed to be the main process controlling the diel cycles of trace elements. Another
possible process that deserves an in-depth assessment is co-precipitation of As and Zn with calcite.
Both processes should be carefully considered to assess the effectiveness of remediation actions currently
in progress at Baccu Locci
The geological and metallogenic map of the Baccu Locci mine area (Sardinia, Italia)
No full textThe study area is in the nappe zone of the Sardinian Variscides in the southeast part of the Island of Sardinia (Italy), and extends between 39°33′14′′/9°30′14′′ (NW corner) and 39°30′09′′/9°35′36′′ (SE corner). The area shows a section of the Variscan orogen in Sardinia with three tectonic units that were stacked and folded during the Middle Carboniferous Variscan tectonics.
The presented 1:10,000 scale geological map, the cross sections and the 3D models illustrate the complicated tectonic setting of the area, resulting from the polyphasic Variscan collisional evolution as well as from later extensional stages. The geometry resulting from progressive deformation is strongly noncylindrical; it is not balanceable because the polypahsic deformation with different tectonic transport directions and the loss in volume in the different formations occurred under greenschist facies metamorphism. The use of 3D modelling of geological surfaces greatly improved both the map and cross-sections.
The Variscan basement of the study area hosts one of the most important mining zones of SE Sardinia (Baccu Locci mine area), which was active until 1961 for the extraction of AsPy, PbS and ZnS. Recent studies also found a noteworthy occurrence of Au. The Baccu Locci mine is assumed to be the eastern part of a mineralized corridor linked with the Variscan shear zone.
A metallogenic map of the Baccu Locci mine area at 1:7,500 scale is included in this paper. The primary map associated with this paper actually represents a 4D model (spatial and time dimensions) of ore bodies hosted in a crystalline basement and highlights the overprinting of different paragenetic sequences of mineralizations and their relationships with pre-existing structures
Synthesis, characterization and thermochemistry of a Pb-jarosite
No full textThe enthalpy of formation from the elements of a well-characterized synthetic Pb-jarosite sample corresponding to the chemical formula (H3O)0.74Pb0.13Fe2.92(SO4)2(OH)5.76(H2O)0.24 was measured by high temperature oxide melt solution calorimetry. This value (View the MathML source = −3695.9 ± 9.7 kJ/mol) is the first direct measurement of the heat of formation for a lead-containing jarosite. Comparison to the thermochemical properties of hydronium jarosite and plumbojarosite end-members strongly suggests the existence of a negative enthalpy of mixing possibly related to the nonrandom distribution of Pb2+ ions within the jarosite structure. Based on these considerations, the following thermodynamic data are proposed as the recommended values for the enthalpy of formation from the elements of the ideal stoichiometric plumbojarosite Pb0.5Fe3(SO4)2(OH)6: View the MathML source = −3118.1 ± 4.6 kJ/mol, View the MathML source = −3603.6 ± 4.6 kJ/mol and S° = 376.6 ± 4.5 J/(mol K). These data should prove helpful for the calculation of phase diagrams of the Pb–Fe–SO4–H2O system and for estimating the solubility product of pure plumbojarosite. For illustration, the evolution of the estimated solubility product of ideal plumbojarosite as a function of temperature in the range 5–45 °C was computed (Log(Ksp) ranging from −24.3 to −26.2). An Eh–pH diagram is also presented
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