SIGLEITItal
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... Belli Sabrina Barbizzi Philippe Cyffroy Giovanni Paolo Fanzutti Volodya Kanivets Rita Ocone Raffaella ... large but typ-ically unknown uncertainty contribution to the final ana-lytical data. ... ance, METTLER AT 400 (0.0001 g). 5.... more
... Belli Sabrina Barbizzi Philippe Cyffroy Giovanni Paolo Fanzutti Volodya Kanivets Rita Ocone Raffaella ... large but typ-ically unknown uncertainty contribution to the final ana-lytical data. ... ance, METTLER AT 400 (0.0001 g). 5. Analytical effects: the gamma-emitters radionuclides ...
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Natural building materials, characterised by middle-low-activity concentrations of primordial radionuclides ((40)K, (232)Th and (238)U series) are widely used in Italy. Since natural materials reflect the geological variability of their... more
Natural building materials, characterised by middle-low-activity concentrations of primordial radionuclides ((40)K, (232)Th and (238)U series) are widely used in Italy. Since natural materials reflect the geological variability of their sites of origin, a systematic study was carried out in the province of Rome and the results are reported in this paper. In the present work, in order to evaluate average, minimum and maximum contents of primordial radionuclides, more representative lithologies outcropping on the territory of the province of Rome were identified and around 150 samples were collected. Also, these lithologies were characterised from a radioprotection point of view, by means of the evaluation of the index, I, when they are used as building materials. The results confirm the high-primordial radionuclide content within some materials used in Latium (central Italy). Although the study was carried out in a limited area, the results confirm considerable variation in the primo...
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... CAPITOLO 15 Autori: Giovanni AGNESOD(3), Mario DIONISI(1), Leandro MAGRO(1), Giuseppe MENNA(1), Rita OCONE(1), Carmelina SALIERNO(1), Francesco SALVI(1), Roberto SOGNI(2), Giancarlo TORRI(1), Flavio TROTTI(4), Chiara ZAMPIERI(4),... more
... CAPITOLO 15 Autori: Giovanni AGNESOD(3), Mario DIONISI(1), Leandro MAGRO(1), Giuseppe MENNA(1), Rita OCONE(1), Carmelina SALIERNO(1), Francesco SALVI(1), Roberto SOGNI(2), Giancarlo TORRI(1), Flavio TROTTI(4), Chiara ZAMPIERI(4), Paolo ZEPPA(1 ...
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Summary A single-axis sodar system, with off-line Doppler analysis, has been operated in the month of January 1987 at the Italian Antarctic base near Terra Nova Bay. The instrument was installed in complex terrain at a distance of... more
Summary A single-axis sodar system, with off-line Doppler analysis, has been operated in the month of January 1987 at the Italian Antarctic base near Terra Nova Bay. The instrument was installed in complex terrain at a distance of approximately 1 km from the shore-line. During the campaign the area around the station, for a width of about (23) km from the
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In the Antarctic boundary layer, some phenomena appear to be particularly enhanced with respect to those at midlatitudes. Thermal stratifications are present almost all year and can substain drainage flows of different types. Several... more
In the Antarctic boundary layer, some phenomena appear to be particularly enhanced with respect to those at midlatitudes. Thermal stratifications are present almost all year and can substain drainage flows of different types. Several episodes of flows with different potential temperature and consequently with different buoyancy were observed on the Nansen Ice Sheet by a sodar. Two case studies are presented in which a comparison with the data of the automatic weather stations located on the Reeves and the Priestley glaciers as well on the Nansen Ice Sheet have been used. As a main result, we saw that during the summer time, the flow from the Reeves glacier may superimpose the one from the Priestley, in contrast with the current opinion based on the automatic weather station measurements averaged over the entire year. Also, an episode of barrier-katabatic flow interaction is shown in which the first is negatively buoyant in comparison with the second. Since the wind profile frequently showed a great variability with height, the importance of using remote sensing sensors in studies that realistically want to model the dynamics of the Antarctic boundary layer has been emphasized.
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Research Interests: Mechanical Engineering, Chemical Engineering, Modeling, Prediction, Two Phase Flow, and 18 moreMorphology, Powder technology, Fluidization, Tomography, Kinetic Theory, Bubble, Comparative Analysis, Bubble Column, Shear Stress, Hydrodynamics, Fluidized Bed, Cohesion, Electrical Capacitance Tomography, Capacitance, Flow Regime, Extract, Expansion, and Tomografía
In a previous paper (J. Non-Newtonian Fluid Mech. 76 (1998) 5), the analogy between the methodology typical of the dynamics of polymeric liquids and those used in granular flow theory was investigated. It was shown that such a methodology... more
In a previous paper (J. Non-Newtonian Fluid Mech. 76 (1998) 5), the analogy between the methodology typical of the dynamics of polymeric liquids and those used in granular flow theory was investigated. It was shown that such a methodology could be successfully extended to granular flow, and then it was speculated on the possibility of extending it to diverse areas.
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ABSTRACT
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ABSTRACT Summary A method for the determination of low-level radium isotopes in mineral and environmental water samples by alpha-spectrometry has been developed. Radium-225, which is in equilibrium with its mother 229Th, was used as a... more
ABSTRACT Summary A method for the determination of low-level radium isotopes in mineral and environmental water samples by alpha-spectrometry has been developed. Radium-225, which is in equilibrium with its mother 229Th, was used as a yield tracer. Radium were preconcentrated from water samples by coprecipitation with BaSO4and iron (III) hydroxide at pH 8-9 using ammonia solution, then isolated from uranium, thorium and iron using a Microthene-TOPO chromatography column at 8M HCl, separated from barium in a cation-exchange resin column using 0.05M 1,2-cyclohexylenedinitrilotetraacetic acid monohydrate at pH 8.5 as an eluant, and finally electrodeposited on a stainless steel disc in a medium of 0.17M (NH4)2C2O4at pH 2.6 and current density of 400 mA. cm-2, and counted bya-spectrometry. Optimum experimental conditions for radium separation, purification and electrodeposition have been studied and discussed in the paper. The lower limits of detection of the method are 0.11 mBq. l-1for 226Ra, 228Ra and 224Ra, respectively, if 2 l of water are analyzed. The method has been checked with a certified reference material IAEA-Soil-6 supplied by the International Atomic Energy Agency and reliable results were obtained. Eighteen water samples collected in Italy have been analyzed with the method, the mean radiochemical yields for radium were 86.2±6.5%. The obtained radium concentrations were in the range of 0.50-60.8 mBq. l-1for 226Ra, of 0.10-25.7 mBq. l-1for 228Ra, and of£LLD-7.97 mBq. l-1for 224Ra. The 228Ra/226Ra and 224Ra/226Ra ratios were in the range of 0.189-4.45 and£LLD-0.941, respectively.
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Elementary compressible flow problems of granular materials have been analyzed in the past few years, and even only moderately complex problems present subtle difficulties, because of inelasticity of particle-particle collisions. Some... more
Elementary compressible flow problems of granular materials have been analyzed in the past few years, and even only moderately complex problems present subtle difficulties, because of inelasticity of particle-particle collisions. Some analogies with classical gas dynamics exist, and those make it possible to approach basic problems using tools used there. Some results can be obtained from such an approach: standing compression and rarefaction waves, thermal relaxation tails, and the like.
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In a recent Letter, we have shown how a thermodynamic-like theory can be developed starting from the periodic production of certain proteins in the cell cycle [Chem. Phys. Lett. 377 (2003) 627]. The kinetic equations for two protein... more
In a recent Letter, we have shown how a thermodynamic-like theory can be developed starting from the periodic production of certain proteins in the cell cycle [Chem. Phys. Lett. 377 (2003) 627]. The kinetic equations for two protein complexes regulating the cell cycle were assumed to be in Hamiltonian form. This implies that the underlying system is conservative, a hypothesis
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ABSTRACT Continuum lumping is a methodology widely used to describe the kinetic or thermodynamic behaviour of complex reactive mixtures of various components all undergoing similar types of reactions (e.g., cracking, pyrolysis,... more
ABSTRACT Continuum lumping is a methodology widely used to describe the kinetic or thermodynamic behaviour of complex reactive mixtures of various components all undergoing similar types of reactions (e.g., cracking, pyrolysis, oligomerisation). The methodology is particularly convenient when the number of species involved is very large and the species can be characterised by properties that can be measured in a continuous fashion, as for instance in a chromatogram. By applying the lumping methodology, a large reactive system can be reduced to a simpler and more tractable one. In the present paper, the continuum lumping methodology is applied to the hydrocracking of Fischer–Tropsch waxes (n-paraffins), extending a previous model by Laxminarasimhan et al. (1996). Specifically, the role of the type-distribution function is investigated by employing two expressions of such function and by studying how it affects the model predictions. The effect of the operating conditions (namely temperature, pressure and hydrogen to feed ratio) on the hydrocracking process is also investigated. The model parameters are estimated by using experimental data obtained from a bench scale trickle bed reactor for specified ranges of operating conditions.
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In the period June–July 1992, four Doppler sodars were operated simultaneously in Rome and the surrounding area. The data have been used to investigate the contributions from sea breeze events to the local low-level circulation. Three... more
In the period June–July 1992, four Doppler sodars were operated simultaneously in Rome and the surrounding area. The data have been used to investigate the contributions from sea breeze events to the local low-level circulation. Three days in which synoptic-scale pressure gradients were weak have been selected. A number of characteristics of the sea breeze are examined including the onset