METEOR RADAR STATISTICS. II

1966 ◽  
Vol 44 (7) ◽  
pp. 1593-1602 ◽  
Author(s):  
Peter M. Millman ◽  
Bruce A. McIntosh
Keyword(s):  
Mass Distribution ◽  
Interplanetary Space ◽  
Meteor Radar ◽  
Meteor Flux

Mean daily values of meteor flux for three categories of meteor echoes are tabulated for the period 1958 to 1962. The variation of echo rate with echo duration is studied. The difficulty of using this relation to determine the mass distribution of meteoroids in interplanetary space is noted.

THE DETERMINATION OF METEOR MASS DISTRIBUTION FROM RADAR ECHO COUNTS

1966 ◽  
Vol 44 (11) ◽  
pp. 2729-2748 ◽  
Author(s):  
B. A. McIntosh
Keyword(s):  
Mass Distribution ◽  
Electron Attachment ◽  
Meteor Radar ◽  
Low Velocity ◽  
Wide Beam ◽  
Radar Echoes ◽  
Long Duration ◽  
Radar Echo ◽  
Meteor Trails

In relating the frequency distribution of the durations of radar echoes from meteor trails to the mass distribution of the meteoroid flux, two major effects must be taken into account. Because bright meteors tend to be observable by radar from any angle, the rate of long-duration echoes is enhanced relative to short-duration echoes. This effect is particularly pronounced for the Ottawa radar which has wide-beam antennas. On the other hand, the effect of electron attachment is to suppress the long-duration echo count, particularly for low-velocity meteors, which produce ionized trails at lower altitudes.The influence of both these effects on the observational results from the Ottawa meteor radar is examined quantitatively.

Outbursts of comet Schwassmann-Wachmann 1, and the cloud of interplanetary boulders

1974 ◽  
Vol 22 ◽  
pp. 307 ◽  
Author(s):  
Zdenek Sekanina
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Interplanetary Space ◽  
Porous Matrix ◽  
Maximum Diameter ◽  
Expansion Velocity ◽  
Solid Constituent ◽  
Meteoric Material ◽  
Periodic Comet

AbstractIt is suggested that the outbursts of Periodic Comet Schwassmann-Wachmann 1 are triggered by impacts of interplanetary boulders on the surface of the comet’s nucleus. The existence of a cloud of such boulders in interplanetary space was predicted by Harwit (1967). We have used the hypothesis to calculate the characteristics of the outbursts – such as their mean rate, optically important dimensions of ejected debris, expansion velocity of the ejecta, maximum diameter of the expanding cloud before it fades out, and the magnitude of the accompanying orbital impulse – and found them reasonably consistent with observations, if the solid constituent of the comet is assumed in the form of a porous matrix of lowstrength meteoric material. A Monte Carlo method was applied to simulate the distributions of impacts, their directions and impact velocities.

Type II Solar Radio Bursts over Solar Cycle 21

1994 ◽  
Vol 144 ◽  
pp. 283-284
Author(s):  
G. Maris ◽  
E. Tifrea
Keyword(s):  
Solar Radio ◽  
Interplanetary Space ◽  
Impulsive Phase ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Strong Energy ◽  
Mass Ejection ◽  
Geophysical Effect ◽  
Radio Event

The type II solar radio bursts produced by a shock wave passing through the solar corona are one of the most frequently studied solar activity phenomena. The scientific interest in this type of phenomenon is due to the fact that the presence of this radio event in a solar flare is an almost certain indicator of a future geophysical effect. The origin of the shock waves which produce these bursts is not at all simple; besides the shocks which are generated as a result of a strong energy release during the impulsive phase of a flare, there are also the shocks generated by a coronal mass ejection or the shocks which appear in the interplanetary space due to the supplementary acceleration of the solar particles.

Solar Filaments as Tracers of Subsurface Processes

2000 ◽  
Vol 179 ◽  
pp. 177-183
Author(s):  
D. M. Rust
Keyword(s):  
Magnetic Fields ◽  
Magnetic Flux ◽  
Coronal Mass Ejections ◽  
Interplanetary Space ◽  
Intermediate Stage ◽  
Coronal Plasma ◽  
Magnetic Helicity ◽  
The Sun ◽  
New Paradigm ◽  
Solar Filaments

AbstractSolar filaments are discussed in terms of two contrasting paradigms. The standard paradigm is that filaments are formed by condensation of coronal plasma into magnetic fields that are twisted or dimpled as a consequence of motions of the fields’ sources in the photosphere. According to a new paradigm, filaments form in rising, twisted flux ropes and are a necessary intermediate stage in the transfer to interplanetary space of dynamo-generated magnetic flux. It is argued that the accumulation of magnetic helicity in filaments and their coronal surroundings leads to filament eruptions and coronal mass ejections. These ejections relieve the Sun of the flux generated by the dynamo and make way for the flux of the next cycle.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

Mass distribution and Dynamical State of Galaxy Clusters in the LZLS Sample

2006 ◽  
Vol 20 ◽  
pp. 269-270 ◽  
Author(s):  
L.E. Campusano ◽  
E.S. Cypriano ◽  
L. Jr. Sodré ◽  
J.-P. Kneib
Keyword(s):  
Galaxy Clusters ◽  
Mass Distribution ◽  
Dynamical State

Mass distribution of hydrodynamic jets produced on the national ignition facility

2006 ◽  
Vol 133 ◽  
pp. 107-110 ◽  
Author(s):  
B. E. Blue ◽  
S. V. Weber ◽  
D. T. Woods ◽  
M. J. Bono ◽  
S. N. Dixit ◽  
...  
Keyword(s):  
Mass Distribution ◽  
National Ignition Facility

Empirical analysis of market boundaries in telecommunications

2019 ◽  
pp. 90-111 ◽  
Author(s):  
Natalia S. Pavlova ◽  
Andrey Е. Shastitko
Keyword(s):  
Law Enforcement ◽  
Empirical Analysis ◽  
Mass Distribution ◽  
End Users ◽  
Economic Modeling ◽  
Empirical Approach ◽  
Antitrust Law ◽  
Technological Changes ◽  
Loss Analysis ◽  
E Mail

The article deals with the problem of determining market boundaries for antitrust law enforcement in the field of telecommunications. An empirical approach has been proposed for determining the product boundaries of the market in the area of mass distribution of messages, taking into account the comparative characteristics of the types and methods of notification (informing) of end users; the possibilities of switching from one way of informing to another, including the evolution of such opportunities under the influence of technological changes; switching between different notification methods. Based on the use of surveys of customers of sending SMS messages, it is shown that the product boundaries should include not only sending messages via SMS, but also e-mail, instant messengers, Push notifications and voice information. The paper illustrates the possibilities of applying the method of critical loss analysis to determining the boundaries of markets based on a mixture of surveys and economic modeling.

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