Mutual gravitational potential ofN solid bodies

The mutual gravitational potential ofN solid bodies is expanded without approximation in terms of harmonic coefficients of each body. As an application the Euler dynamical equations for the motion of the axis of figure of the rigid Earth are integrated analytically by the method of variation of parameters.     

Proper motion surveys in the infrared

Current and future wide field surveys in infrared passbands present opportunities for ultra low‐mass stellar sample selection via proper motions, as well as or instead of purely photometric techniques. Furthermore, proper motion measurements yield additional clues as to candidate membership of cluster or field (kinematic) populations. In this paper we review some recent results and speculate as to the possibilities afforded by the next generation of wide‐field infrared surveys. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Experiments on numerical modeling of intense convection

Results of numerical simulations using the WRF-ARW nonhydrostatic model are presented for eight episodes of intense convection over European Russia in the summer of 2007. The calculations were performed on four nested grids with horizontal grid meshes of 27, 9, 3, and 1 km. Convection was parametrized on the first two grids and explicitly resolved on the other two. It has been found that simulations on finer grids with explicit calculation of convective flows make it possible to reproduce heavy rainfalls and strong-wind zones in the areas of intense convection. A preliminary verification of the short-range predictions of convective systems shows that the maximum 12-h precipitation totals and the maximum winds at 10 m are close, in the order of magnitude, to the observed values. Prediction of convection centers is the weakest point. Difficulties in the model verification associated with the absence of data with high space-time resolution are discussed.     

Meteorological and synoptic aspects of the formation and evolution of the Novorossiysk Bora

The genetic and synoptic classifications of the Novorossiysk Bora are created using the data of daily observations at the Novorossiysk meteorological station and other available synoptic information. Obtained are the quantitative criteria of these classifications, and on this base worked out are the basic scenarios of the generation and evolution of this dangerous phenomenon on the Black Sea coast of Russia. According to the genetic classification, the Bora was divided into four types: frontal, air-mass, monsoon, and gravity. Quantitative criteria worked out for each type can be used for the more accurate forecast of this destructive phenomenon near Novorossiysk. According to the synoptic classification, four classes were distinguished: Azores, North Atlantic, Siberian, and Arctic.     

Contributions from oceanic and ionospheric dynamos to the lunar daily variation at Alibag

Summary. The contributions from the oceanic and ionospheric dynamos, L_o and L_I respectively, to the geomagnetic lunar daily variation, L , at Alibag, a coastal station in the Indian equatorial region, are calculated from the L harmonics derived from a 41–yr long series of observations. The analysis in the calendar months shows a steady and significant ocean dynamo contribution in the vertical component, Z, in all the months except April. Examination, by an analysis of the data year by year, of the association of L_o and L_I with varying solar and magnetic activities reveals, surprisingly, a stable correlation between the magnetic activity index A _P and the oceanic part in the horizontal and vertical components but not in declination, which probably indicates the influence of induced currents, along the latitudes, on L _o.     

Geochemistry of Suspended Matter from Waters of the Amazon Basin

The geochemical study of the suspended matter in the waters of the Amazon River and its tributaries revealed that the chemical composition of this material ranges widely; however, generally, it is similar to the average composition of the suspended matter in the rivers and clayey sedimentary rocks around the world. Against this background, an essential regional Hg enrichment due to the anthropogenic factor is distinguished. The suspensions from the so-called clear waters from the tributaries of the Amazon River—Xingu and Trombetas—demonstrate the local enrichment in Pb, Sn, Zn, and organic carbon indicating the ore mineralization of the drainage basin, and points to the presence of metal-organic complexes.     

Distribution and properties of placer ilmenite in East Rosetta beach sands,Egypt

This work deals with a concise but comprehensive study of Ilmenite distribution in the beach sands of east Rosetta. This area extends for 28 km east of Rosetta Nile branch-estuary. The sands come out of the estuary are subjected to north-westerly winds and a current parallel to the beach line from west to east. The significant data about this heavy mineral distribution are shown in Fig. 1 and 2, and summerized in Tables 1–5. The Ilmenite properties especially the trace elements are also comprehended. Systematic withdrawal of 258 auger samples were distributed in a grid with 400 m parallel, and 200 m perpendicular to the beach line and 1 m depth. The main Ilmenite concentrations are present in three areas A, B and C. The Ilmenite content varies generally between 2. 2% as minimum and 18. 12% as maximum. The top meter (upper 1 m) contains 2. 91 million dry tons in an area covering 21 km². The Ilmenite forms the major mineral in the beach sands nearly north of Rosetta (Fig. 1 and 2). The principal richness of Ilmenite is contained in the area "B" which is close to Abu-Khashaba. The average value of Ilmenite all over the beach comes to 8. 128%. The mineral is found in normal distribution (Fig. 3) and this confirmed the deposition parallel to the beach line and irregular deposition perpendicular to the beach line. This is in accordance with the dominant current from the west to the east. The Magnetite is separated by using natural small magnet in one hand, as well as the Ilmenite, Hematite, Monazite, Zircon, Rutile and Garnet in the other hand by using the FRANTZ Isodynamic separator. The Ilmenite is estimated by using the separator in two different steps of suitable tilt and current.