ALBERT

Notes: [Auszug] To carry out this programme we first of all compiled a catalogue of all stars hotter than O9-5, all supergiants hotter than AO, and clusters with their earliest member hotter than B5, for a region of radius 1 kpc around the Sun. Using Morton and Adams's recent calculations1 of stellar atmospheres ...

Notes: [Auszug] We want to make the following remarks concerning the data in Table 1. (i) MP 0254, MP 1911 and AP 2303 seem to lie beyond the galactic electron layer, and MP 1857 at its edge. (ii) As our list of HII regions does not extend beyond 1 kpc, we can only put an upper bound on the distances to MP 1154, ...

Notes: [Auszug] Some time ago Large et al.1,2 reported that the pulsars tended to cluster a few degrees south of the galactic plane, while Davidson and Terzian3 noted a complete absence of pulsars between bII= +6 and +25. Since that time, the former effect has persisted, suggesting that it is real, but a couple of ...

Notes: Abstract In this paper, we apply the ideas presented by one of us (Prentice, 1978a, b) for the development of the proto-solar cloud into a system of Laplacian rings to the development of the protoplanetary clouds which ultimately led to Jupiter, Saturn and Uranus. We show that if one accepts this scenario — especially the idea of supersonic turbulence in the proto-planetary clouds — one can satisfactorily explain, on the basis of fixing a single adjustable parameter, both the geometric precession of the orbital radii of the regular satellite systems of these three planets and the chemical composition and mass distribution of these satellites. We suggest that thermal stirring in the proto-planetary cloud in the vicinity of the surface of the planet may be responsible for the smaller masses of some of the inner satellites as well as for the formation of the rocky rings of Uranus. The icy rings of Saturn are suggested to be the product of condensation processes in a continuous gaseous disc within the Roche limit of the planet.

Notes: Commissioned by the Ministry of Agriculture, Fisheries and Food, the Department of Health and carried out by Social and Community Planning Research and MRC Dunn Nutrition Unit, the dental hospitals of the Universities of Newcastle and Birmingham and the Department of Epidemiology of the University of London, this research forms part of the National Diet and Nutrition Survey. Set up in 1992 the surveys cover representative groups of the population and examine the diet of the over-65s in terms of actual dietary intake, habits, energy and nutrient intakes, physical measurements. Regional and socio-economic comparisons are made.

Notes: [Auszug] The regular satellite systems of Jupiter, Saturn and Uranus are remarkable for the near coplanarity and circularity of their orbits. In addition, the orbital radii Rn, when numbered from the outermost members inwards (n = 0, 1, 2,...), form nearly perfect geometric sequences R R(1) where for ...

Notes: [Auszug] Microradiographs of ground bone sections also reveal that the more recently formed osteons contain less mineral than older ones. It seems necessary to correlate these two findings on a single specimen of bone before assuming that the weakly fluorescent and poorly calcified osteons are the same. A ...

Notes: Abstract A theory for the origin and bulk chemical composition of the Galilean satellites is presented — to coincide with the start of the 2-year orbital tour of this satellite system by the Galileo Orbiter. The theory is based on the author's modern Laplacian theory of solar system origin (Prentice 1978a). The nub of the work reported here is that the Jupiter system is indeed a miniature planetary system that formed by much the same physical and chemical processes that were responsible for the condensation of the sun's own family of planets. In particular, a phenomenon of supersonic turbulent convection which I claim caused the proto-solar cloud to rid excess spin angular momentum, by shedding a concentric family of orbiting gas rings at the present planetary orbits, may also have operated with similar effect within the proto-Jovian cloud. Several predictions are made for the bulk chemical composition and physical structure of the icy Galilean satellites which, it is hoped, can be tested by the Galileo Orbiter. The mean density of Callisto is consistent with that of a chemically homogeneous body consisting of about 50% rock, 45% water ice, and 5% ammonia ice, incorporated as the hydrate NH3·H2O. Such a higher-than-solar mass abundance ratio of rock to ice arises naturally within the proto-Jovian cloud since (i) only 34% of the available H2O vapor within the gas ring shed by the proto-solar cloud at Jupiter's orbit was condensed in solid form, and (ii) gravitational sedimentation of solids onto the mean orbit of the proto-solar gas ring leads to an enhancement in the heavy element fraction of the captured primitive Jovian atmosphere. All in all, I predict Jupiter's primitive atmosphere to be enhanced by a factor ζen ≈ 2 in its rock mass fraction (including S) and by a factor ≈ 1.3 in its water content, relative to solar abundances. NH3 and CH44 are present in almost solar proportions. Initially, Ganymede consisted of a chemically uniform mixture of rock and water ice in the proportions 0.524 : 0.476. The observed mean density of this satellite, however, lies midway between the mean densities expected for homogeneous and fully differentiated rock/ice bodies. The calculations presented here suggest that this body is about half-differentiated. I predict that the Galileo Orbiter will find the mean axial moment-of-inertia factor of Ganymede to be 0.35 ± 0.01. The circum-Jovian gas ring from which Europa condensed had a temperature of 302 K and a mean orbit gas pressure of 2.8 bar. Initially, this satellite consisted of a uniform mix of hydrated rocks, of which brucite Mg(OH)2 was the principal constituent. The observed mean density of Europa coincides with that expected for this mix, provided that its 9.4% native H2O content is now fractionated from the rock and resides at the satellite surface, forming a frozen mantle some 155 km thick. Regretfully, the mean density of Io cannot be matched by the solid composition reported here. Perhaps this satellite has a molten interior.

Notes: Abstract The origin of Jupiter and the Galilean satellite system is examinedin the light of the new data that has been obtained by the NASA Galileo Project. In particular, special attention is given to a theory of satellite origin which was put forward at the start of the Galileo Mission and on the basis of which several predictions have now been proven successful (Prentice, 1996a–c). These predictions concern the chemical composition of Jupiter's atmosphere and the physical structure of the satellites. According to the proposed theory of satellite origin, each of the Galilean satellites formed by chemical condensation and gravitational accumulation of solid grains within a concentricfamily of orbiting gas rings. These rings were cast off equatorially by the rotating proto-Jovian cloud (PJC) which contracted gravitationally to form Jupiter some 4 $$\frac{1}{2}$$ billion years ago. The PJC formed from the gas and grains left over from the gas ring that had been shed at Jupiter's orbit by the contracting proto-solar cloud (PSC). Supersonic turbulentconvection provides the means for shedding discrete gas rings.The temperatures Tn of the system of gas rings shed by the PSCand PJC vary with their respective mean orbital radii Rn (n = 0, 1, 2, Ϊ ) according as Tn ∝ Rn -0.9. If the planet Mercury condenses at 1640 K, so accounting for the high density ofthat planet via a process of chemical fractionation between iron and silicates, then Tn at Jupiter's orbit is 158 K. Only 35% of the water vapour condenses out. Thus fractionation between rock and ice, together with an enhancement in the abundance of solids relative to gas which takes place through gravitational sedimentation of solids onto the mean orbit of the gas ring, ensures nearly equal proportions of rock and ice in each of Ganymede and Callisto. Io and Europa condense above the H2O ice point and consist solely of hydrated rock (h-rock). The Ganymedan condensate consists of h-rock and H2O ice. For Callisto, NH3 ice makes up ∼5% of the condensate mass next to h-rock (∼50%) and H2O ice (∼45%). Detailed thermal and structural models for each of Europa, Ganymedeand Callisto are constructed on the basis of the above initial bulk chemicalcompositions. For Europa (E), a predicted 2-zone model consisting of a dehydrated rock core of mass 0.912ME and a 150 km thick frozen mantle of salty H2O yields a moment-of-inertiacoefficient which matches the Galileo Orbiter gravity measurement. For Ganymede (G), a 3-zone model possessing an inner core of solid FeS and mass ∼0.116MG, and an outer H2O ice mantle of mass ∼0.502MG is needed to explain the gravity data.Ganymede's native magnetic field was formed by thermoremanent magnetization of Fe3O4. A new Callisto (C) model is proposed consisting of a core of mass 0.826MC containing a uniform mixture of h-rock (60% by mass) and H2O and NH3 ices, and capped by a mantle of pure ice. This model may have the capacity to yield a thin layer of liquid NH3ċ2H2O at the core boundary, in line with Galileo's discovery of an induced magnetic field