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Riassunto Coi dati rilevati nel Settembre 1924 dalla Mario Bianco a Nord dello Stretto di Messina si determinano i coefficienti di diffusione turbolenta, longitudinale e trasversale, per gli strati superficiali della corrente scendente convogliata dallo Stretto medesimo: ottenendo valori in buon accordo con quelli calcolati da altri AA. per altre correnti marine. Inoltre si forniscono elementi sull'estensione per diffusione in profondità delle acque ioniche penetrate nel Tirreno.
Summary Using the data gathered by the ship Mario Bianco during September 1924 the Authors make an attempt to calculate the longitudinal and lateral eddy-diffusion for the current north of the Messina-strait: the resulting coefficients agree well with the already known values. Further, the headlines of the diffusion of the Ionian waters in the Thyrrenian Sea are inferred and discussed.相似文献
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The main results of a two-year project aimed at comparing full-scale tests, wind tunnel tests, and numerical analysis predictions are presented. Pressure measurements were obtained from both full-scale tests and wind tunnel tests, in upwind and downwind conditions. The upwind wind tunnel test condition was modelled using a Vortex Lattice code, while the downwind wind tunnel test was modelled using a Navier-Stokes code. The pressures obtained from the three different methods are compared on three horizontal sections of the headsail, mainsail and asymmetric spinnaker. In general the pressure from the three experiments showed good agreement. In particular, very good agreement was obtained between the numerical computations and the wind tunnel test results. Conversely, the results from the downwind full-scale pressure measurements showed less similarity due to a slightly tightened trim being used for the spinnaker in the on-water tests. Full-scale tests allow the action of unsteadiness due to the wind, wave and yacht movements to affect the results. This unstable environment caused the asymmetric spinnaker to move around, and a tightened trim was required to prevent the spinnaker from collapsing. 相似文献
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Tiziano Zingales Giovanna Tinetti Ignazio Pillitteri Jérémy Leconte Giuseppina Micela Subhajit Sarkar 《Experimental Astronomy》2018,46(1):67-100
The ARIEL (Atmospheric Remote-sensing Exoplanet Large-survey) mission concept is one of the three M4 mission candidates selected by the European Space Agency (ESA) for a Phase A study, competing for a launch in 2026. ARIEL has been designed to study the physical and chemical properties of a large and diverse sample of exoplanets and, through those, understand how planets form and evolve in our galaxy. Here we describe the assumptions made to estimate an optimal sample of exoplanets – including already known exoplanets and expected ones yet to be discovered – observable by ARIEL and define a realistic mission scenario. To achieve the mission objectives, the sample should include gaseous and rocky planets with a range of temperatures around stars of different spectral type and metallicity. The current ARIEL design enables the observation of ～1000 planets, covering a broad range of planetary and stellar parameters, during its four year mission lifetime. This nominal list of planets is expected to evolve over the years depending on the new exoplanet discoveries. 相似文献
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Mario Bossolasco Giuseppe Cicconi Ignazio Dagnino Antonio Elena Giuseppe Flocchini 《Pure and Applied Geophysics》1964,57(1):221-224
Summary Using the highest global irradiance values (Sun plus sky) at noon derived from the records gathered during the years 1958 to 1963 at Genova, Monte Capellino and Sauze d'Oulx, it is demonstrated that the thermal energy which the Earth receives from the Sun is dependent from the Sun activity. Precisely, an increase of the thermal energy withR
Z occurs up toR
Z=160–170, whereas for greater values ofR
Z the thermal energy received decreases with the increase ofR
Z.
Herrn Prof. Dr.Hans Ertel zu seinem 60. Geburtstag gewidmet. 相似文献
Herrn Prof. Dr.Hans Ertel zu seinem 60. Geburtstag gewidmet. 相似文献
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Giuseppe Cello Ignazio Guerra Luigi Tortorici Eugenio Turco Roberto Scarpa 《Journal of Structural Geology》1982,4(4):385-393
The neotectonic regime in southern Italy has been evaluated by making a comparison between all the available structural and seismological data. The area investigated can be subdivided into four distinct zones which are characterized by different stress regimes. In the Southern Apennines the tensile axis of the stress field is oriented approximately NE-SW while the maximum principal stress (σ1) is subvertical. In Northern Calabria, the tensile axis is ESE-WNW and the σ1 axis is almost vertical. In the Catanzaro trough both the tensile axis and the σ1 axis are subhorizontal and act E-W and N-S, respectively. Finally, the Strait of Messina zone is characterized by a tensile axis oriented E-W and by σ1 being subvertical. 相似文献
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Ignazio Maria Viola 《Ocean Engineering》2009,36(12-13):974-984
A computational fluid dynamics (CFD) code was applied to an America's Cup Class Yacht to investigate sailing performance in a downwind configuration. Apparent wind angles at 45°, 105° and 120° are reported, sailed with mainsail and asymmetrical spinnakers. Numerical results are in good agreement with wind tunnel data. A large mesh investigation was performed, ranging from 60,000 elements up to 37 million elements, which shows a converging trend to the experimental values with differences smaller than 3% in both lift and drag. The most commonly used turbulence models in sail applications were tested and the results are presented here in two meshes with 1 million elements and 6.5 millions, respectively. All turbulence models over-estimate forces more than solving the Navier–Stokes system without any additional equations, hence turbulence models do not increase solution accuracy according to these results. 相似文献
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LAGEOS II perigee rate and eccentricity vector excitations residuals and the Yarkovsky-Schach effect
David M. Lucchesi Ignazio Ciufolini José I. Andrés Roberto Peron Ron Noomen 《Planetary and Space Science》2004,52(8):699-710
We have analysed LAGEOS II perigee rate and eccentricity vector excitation residuals over a period of about 7.8 years, adjusting and computing the satellite orbit with the full set of dynamical models included in the GEODYN II software code. The long-term behaviour of these orbital residuals appears to be characterised by several distinct frequencies which are a clear signature of the Yarkovsky-Schach perturbing effect. This non-gravitational perturbation is not included in the GEODYN II models for the orbit determination and analysis. Through an independent numerical analysis, and using the new LOSSAM model to represent the spin-axis behaviour of the satellite, we propagated the Yarkovsky-Schach effect on LAGEOS II perigee rate and compared the results obtained with the orbital residuals. We have thus been able to satisfactorily fit the amplitude of the Yarkovsky-Schach effect to the observed residuals. Our approach here has proven very successful with very positive results. We have been able to obtain a fractional reduction of about 40% of the post-fit rms with respect to the pre-fit value. When analysing the eccentricity vector residuals, we have been able to obtain a better result in the case of the real component, with a fractional reduction of the post-fit rms of about 49% of the initial value. The analysis of the effect's imaginary component in the eccentricity vector rate is more complicated and deserves additional scrutiny. In this case we need a deeper study which includes the analysis of other unmodelled and mismodelled effects acting on the imaginary component. The study performed in this paper will be of significant relevance not only for the geophysical applications involving LAGEOS II orbit analysis, but also for a refined re-analysis of the general relativistic precession produced by the Earth angular momentum, i.e., the Lense-Thirring effect. 相似文献