The transmission of mass and angular momentum from a satellite or planetary system to its primary

In this paper main implication of basic properties detected in the satellite systems of Jupiter, Saturn and Uranus, and presented by the author in an earlier contribution (Barricelli, 1971b) are investigated. The similarity between the primary periods in the three systems, their apparent relation to the axial rotation periods of the three planets and other features suggesting that collisions with the planetary surfaces may have played a role in the evolution of the three satellite systems are interpreted by assuming that in each case a satellite of unusually large size was originally disintegrated at the Roche limit of its primary. The disintegration of large satellites and their fusion with the respective planets is assumed to be a normal feature in the latest stage of planetary growth and the main cause of axial rotation in the respective planets.These assumptions make it possible to give a selfconsistent interpretation of the similarity between the axial rotation periods of the three planets and their relation to the primary periods (as defined by Barricelli, 1971b) in the three systems.Similar assumptions when applied to the Earth-Moon system make it possible to understand why the Moon, in its closest approach to the Earth is found to have been almost exactly at the Roche limit (Gerstenkorn, 1955; MacDonald, 1964), a coincidence which is too good to be accidental. According to this interpretation our Moon is a portion (representing about one third) of our original satellite, which survived its approach to the Roche limit and the ensuing fusion process with the Earth. It can be shown (see text) that under certain conditions this could leave a residual satellite with a stationary distance from the Earth (which in retrospect would be identified as its lowest distance from the Earth) at the Roche limit.The only other case in which we have observational evidence of parts of a satellite surviving its fusion process at the Roche limit is represented by the rings of Saturn and possibly the small innermost satellite Janus which seems to have been feeding on the rings.     

The axial rotation of planets and transfer of mass and angular momentum from a satellite system to its primary

The main topic of this paper is to investigate the exchange of mass and angular momentum between a satellite or planetary system and its primary, and the effects of this exchange to axial rotations and satellite orbits. Various applications on the calculation of axial rotations, present and past satellite masses and orbits and other implications of the theory are presented.     

Equilibrium and structural studies of silicon(IV) and aluminium(III) in aqueous solution. II. Formation constants for the monosilicate ions SiO(OH)3− and SiO2(OH)22−. A precision study at 25°C in a simplified seawater medium

The hydrolysis of silicic acid, Si(OH)₄, was studied in a simplified seawater medium (0.6 M Na(Cl)) at 25°C. The measurements were performed as potentiometric titrations (hydrogen electrode) in which OH^? was generated coulometrically. The total concentration of Si(OH)₄, B, and log[H⁺] were varied within the limits 0.00075 ? B ? 0.008 M and 2.5 ? -log[H⁺] ? 11.7, respectively. Within these ranges the formation of SiO(OH)₃^? and SiO₂(OH)₂^2? with formation constants log β_?11(Si(OH)₄ ? SiO(OH)₃^? + H⁺) = ?9.472 ±0.002 and log β_?21(Si(OH)₄ ? SiO₂(OH)₂^2? + 2H⁺) = ?22.07 ± 0.01 was established. With B > 0.003 M polysilicate complexes are formed, however, with $\text{-}\text{log[H}{}^{\mathrm{+}}\text{] ? 10.7}$ their formation does not significantly affect the evaluated formation constants. Data were analyzed with the least squares computer program LETAGROPVRID.     

Crust and upper mantle structure of the Bohemian Massif from the dispersion of seismic surface waves

Summary The phase velocity dispersion of Rayleigh waves for the Moxa-Vienna (MOX-VIE) and Moxa-Kaperské Hory (MOX-KHC) profiles, and of both Rayleigh and Love waves for the Kaperské Hory-Ksi (KHC-KSP) profile have been measured and inverted into models of shearwave velocity vs. depth. The three paths cross, respectively, the central part of the Bohemian Massif, its western margin, and the Bohemian Pluton and Cretaceous. For the MOX-VIE profile mean and lower crustal shear wave velocities of 3.7 and 3.9 km/s, respectively, a mean Moho depth of 34 km, and no existence of a low-velocity layer in the lower crust were found. The model obtained for the MOX-KHC profile is characterized by a slightly lower velocity in the lower crust (3.8 km/s), by a slightly lower Moho depth (32 km), and by the appearance of a weak low-velocity channel between 55 and 140 km. The crustal section of the final model for the KHC-KSP profile agrees well with the KHKS82 model derived by Novotný from results of DSS along international profile VII. Our final Rayleigh-wave model has significantly lower shear-wave velocities down to 215 km in the mantle. A systematic difference of 0.18 km/s between the average velocities of Rayleigh and Love waves has been revealed for the depth range from 30 to 215 km. Since almost no contamination of the fundamental Love mode with higher modes has been observed, and since the investigated structure hardly contains an unresolved system of thin, alternately low- and high-velocity layers, the cause of the difference is evidently polarization anisotropy of the upper mantle beneath the Bohemian Massif. It is recommended that the discussed investigations should be supplemented with data from the fan of KSP-GRF (Gräfenberg Array, Germany) paths and from the KHC-BRG (Berggiesshübel, Germany) profile.     

Stress orientation and tectonic regime in the northwestern Valencia Trough from borehole data

The orientation of the maximum horizontal stress S_H is obtained from the analysis of borehole breakouts, covering a depth range from 300 to 3415 m (below sea level) in twelve offshore exploration wells in the northwestern Valencia Trough. The orientation of S_H is roughly coincident with the strike of major extensional structures. From N to S it changes counterclockwise from a NE–SW orientation to a N–S orientation. Estimates of the tectonic regimes indicate that the area is characterised predominantly by normal-faulting with a strike-slip component. Both the stress orientations and the tectonic regimes are consistent with neotectonic studies in the nearby Catalan Coastal Ranges. An established method of estimating the tectonic regime by Moos and Zoback (1990) was modified by the inclusion of a nontrivial cohesion, but this changes the results insignificantly.     

Intermittent Behaviour in Axisymmetric Mean-Field Dynamo Models in Spherical Shells

Axisymmetric mean-field dynamo models in spherical shells are shown to be capable of producing temporally intermittent behaviour. This is of potential importance since (i) it is, as far as we are aware, the first time such behaviour has been produced internally by a mean-field dynamo model in a spherical shell, without requiring any additional assumptions or truncations, and (ii) it may be characteristic of the type of behaviour observed in the long-term record of solar activity, such as Maunder minima. We also show that these types of behaviour persist when the functional form of the alpha quenching is altered and also occur over intervals of the shell thickness and the dynamo number.     

The radial disc structure around a magnetic neutron star: analytic and semi-analytic solutions

The radial structure of a thin accretion disc is calculated in the presence of a central dipole magnetic field aligned with the rotation axis. The problem is treated using a modified expression for the turbulent magnetic diffusion, which allows the angular momentum equation to be integrated analytically. The governing algebraic equations are solved iteratively between 1 and 10⁴ stellar radii. An analytic approximation is provided that is valid near the disruption radius at about 100 stellar radii. At that point, which is approximately 60 per cent of the Alfvén radius and typically about 30 per cent of the corotation radius, the disc becomes viscously unstable. This instability results from the fact that both radiation pressure and opacity caused by electron scattering become important. This in turn is a consequence of the magnetic field which leads to an enhanced temperature in the inner parts. This is because the magnetic field gives rise to a strongly enhanced vertically integrated viscosity, so that the viscous torque can balance the magnetic torque.     

Der untersilurische Brandschiefer von Kuckers (Estland)

Ohne Zusammenfassung     

Die schwedische Hochgebirgsfrage und die Häufigkeit der Überschiebungen

Ohne Zusammenfassung