Thermospheric Density Cells at High Latitudes as Observed by GOCE Satellite: Preliminary Results

Earlier investigations have shown that there is a preponderance of negative velocities in the hydrogen gas at high latitudes, and that in certain areas very little low-velocity gas occurs. In the region 100° <l< 250°, + 40° <b< + 85°, there appears to be a disturbance, with velocities between - 30 and - 80 km/sec. This ‘streaming’ involves about 3000 (r/100)2solar masses (rin pc). In the same region there is a low surface density at low velocities (|V| < 30 km/sec). About 40% of the gas in the disturbance is in the form of separate concentrations superimposed on a relatively smooth background. The number of these concentrations as a function of velocity remains constant from - 30 to - 60 km/sec but drops rapidly at higher negative velocities. The velocity dispersion in the concentrations varies little about 6·2 km/sec. Concentrations at positive velocities are much less abundant.

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The O–C diagrams of minor planets − a new approach to modelling the rotation

International Astronomical Union Colloquium ◽

10.1017/s0252921100031407 ◽

1999 ◽

Vol 173 ◽

pp. 185-188

Author(s):

Gy. Szabó ◽

K. Sárneczky ◽

L.L. Kiss

Keyword(s):

Error Analysis ◽

Time Dependence ◽

Theoretical Work ◽

Minor Planet ◽

Minor Planets ◽

New Approach ◽

Preliminary Results ◽

Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

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Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

International Astronomical Union Colloquium ◽

10.1017/s0252921100064496 ◽

2000 ◽

Vol 179 ◽

pp. 201-204

Author(s):

Vojtech Rušin ◽

Milan Minarovjech ◽

Milan Rybanský

Keyword(s):

Emission Lines ◽

High Latitudes ◽

Green Line ◽

Solar Cycles ◽

The South ◽

Coronal Emission ◽

Local Maxima ◽

The North ◽

Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

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Cyclic Evolution of Sunspots: Gleaning New Results from Old Data

International Astronomical Union Colloquium ◽

10.1017/s0252921100064411 ◽

2000 ◽

Vol 179 ◽

pp. 163-165

Author(s):

S. K. Solanki ◽

M. Fligge ◽

P. Pulkkinen ◽

P. Hoyng

Keyword(s):

Sunspot Number ◽

Sunspot Cycle ◽

Preliminary Results ◽

Butterfly Diagram

AbstractThe records of sunspot number, sunspot areas and sunspot locations gathered over the centuries by various observatories are reanalysed with the aim of finding as yet undiscovered connections between the different parameters of the sunspot cycle and the butterfly diagram. Preliminary results of such interrelationships are presented.

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Systematic effects in observed parallaxes

International Astronomical Union Colloquium ◽

10.1017/s0252921100073887 ◽

1978 ◽

Vol 48 ◽

pp. 31-35

Author(s):

R. B. Hanson

Keyword(s):

Error Estimates ◽

Zero Point ◽

Absolute Zero ◽

Apparent Magnitude ◽

Coherent System ◽

Preliminary Results ◽

General Catalogue ◽

Systematic Effects ◽

New Evidence ◽

Right Ascension

Several outstanding problems affecting the existing parallaxes should be resolved to form a coherent system for the new General Catalogue proposed by van Altena, as well as to improve luminosity calibrations and other parallax applications. Lutz has reviewed several of these problems, such as: (A) systematic differences between observatories, (B) external error estimates, (C) the absolute zero point, and (D) systematic observational effects (in right ascension, declination, apparent magnitude, etc.). Here we explore the use of cluster and spectroscopic parallaxes, and the distributions of observed parallaxes, to bring new evidence to bear on these classic problems. Several preliminary results have been obtained.

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Quantitative Measurements on the Ion Etching of TMV

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072125 ◽

1973 ◽

Vol 31 ◽

pp. 336-337

Author(s):

Irwin Bendet ◽

Nabil Rizk

Keyword(s):

Electron Microscope ◽

Tobacco Mosaic Virus ◽

Mosaic Virus ◽

Ion Current ◽

Beam Diameter ◽

Ion Etching ◽

Preliminary Results ◽

Quantitative Measurements ◽

Monitoring Devices

Preliminary results reported last year on the ion etching of tobacco mosaic virus indicated that the diameter of the virus decreased more rapidly at 10KV than at 5KV, perhaps reaching a constant value before disappearing completely.In order to follow the effects of ion etching on TMV more quantitatively we have designed and built a second apparatus (Fig. 1), which incorporates monitoring devices for measuring ion current and vacuum as well as accelerating voltage. In addition, the beam diameter has been increased to approximately 1 cm., so that ten electron microscope grids can be exposed to the beam simultaneously.

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Granular bainite or granular ferrite? A preliminary TEM investigation of an HSLA-100 steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087239 ◽

1991 ◽

Vol 49 ◽

pp. 584-585

Author(s):

R. Varughese ◽

S. W. Thompson ◽

P. R. Howell

Keyword(s):

Room Temperature ◽

Transformation Products ◽

Accurate Description ◽

Granular Bainite ◽

Preliminary Results ◽

The Past ◽

Light Micrograph ◽

Multiphase Reaction ◽

Detailed Nature

Ever since Habraken and Economopoulos first employed the term granular bainite to classify certain unconventional transformation products in continuously cooled steels, the term has been widely accepted and used, despite the lack of a clear consensus as to the detailed nature of the transformation products which constitute granular bainite. This paper presents the preliminary results of a TEM investigation of an 0.04 wt% C, copper-containing steel (designated HSLA-100). It is suggested that the term granular ferrite rather than granular bainite is a more accurate description of this multiphase reaction product.Figure 1 is a light micrograph of a sample which had been air-cooled from 900°C to room temperature. The microstructure is typical of that which has been termed granular bainite in the past and appears to consist of equiaxed ferritic grains together with other minor transformation products. In order to examine these structures in more detail, both continuously cooled and isothermally transformed and quenched materials have been examined with TEM. Granular bainite has been found in virtually all samples.

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