scholarly journals Remarks on the Size Distribution of Colliding and Fragmenting Particles

1971 ◽  
Vol 12 ◽  
pp. 297-303
Author(s):  
Lothar W. Bandermann
Keyword(s):  
Finite Number ◽  
Size Distribution ◽  
Unit Volume ◽  
Interplanetary Dust ◽  
Fixed Volume ◽  
Two Bodies ◽  
Mass Interval ◽  
Number Of Particles ◽  
The Way

This paper is concerned with some aspects of determining the evolution of the size distribution of a finite number of mutually colliding and fragmenting particles such as the asteroids or interplanetary dust. If n(m, t) is the number of particles per unit volume per mass interval at time t, then n = dn/dt is the rate at which that number changes with time. This rate can be calculated if the laws are known according to which the colliding bodies erode one another and fragment and if the influence of collisions on the motion of the particles is known. To reduce the complexity of the problem, one assumes that the speed of approach between the bodies is always the same vcoll and that they, as well as the debris, occupy a fixed volume (“particles in a box”). Only collisions between two bodies are considered, and the way in which erosion and fragmentation occurs at a given value of vcoll depends only on their masses. The particles are assumed to be spherical.

scholarly journals Statistical error in counting experiments

1935 ◽  
Vol 149 (868) ◽  
pp. 467-486 ◽  
Keyword(s):  
Finite Number ◽  
Statistical Error ◽  
Single Particles ◽  
Exact Determination ◽  
Statistical Laws ◽  
The Way

Experiments in which single particles are studied with the aid of counters would, in principle, lead to an exact determination of the statistical laws governing the behaviour of these particles if the number of counted particles were infinitely large. With a finite number of counts, however, a finite statistical error will always remain. This error depends upon the number of counts and upon the way in which one makes use of the counter readings to calculate the parameters entering into the statistical laws. The purpose of the following investigation is to show for some typical cases which way of calculating has to be adopted in order to make the error a minimum.

On the size distribution and physical properties of interplanetary dust grains

Icarus ◽  
1980 ◽  
Vol 43 (3) ◽  
pp. 350-372 ◽  
Author(s):  
L.B. Le Sergeant D'Hendecourt ◽  
Ph.L. Lamy
Keyword(s):  
Physical Properties ◽  
Size Distribution ◽  
Interplanetary Dust ◽  
Dust Grains

Specific Heat of Square Spin Ice in Finite Point Ising-Like Dipoles Model

2015 ◽  
Vol 245 ◽  
pp. 23-27 ◽  
Author(s):  
Yuriy Shevchenko ◽  
Vitalii Kapitan ◽  
Konstantin V. Nefedev
Keyword(s):  
Finite Number ◽  
Statistical Models ◽  
Statistical Physics ◽  
Calculation Methods ◽  
Magnetostatic Interaction ◽  
Finite Point ◽  
Magnetic Dipoles ◽  
Higher Temperature ◽  
Gibbs Formalism ◽  
Number Of Particles

In the model of finite number (up to 24) of point Ising-like magnetic dipoles with magnetostatic interaction on square 2D lattice within the framework of statistical physics, with using Gibbs formalism and by the means of Metropolis algorithm the heating dependence of temperature has been evaluated. The temperature dependence of the heat capacity on finite number of point dipoles has the finite value of maximum. Together with increase of the system in size the heating peak grows and moves to the area with higher temperature. The obtained results are useful in experimental verification of statistical models, as well as in development and testing of approximate calculation methods of systems with great number of particles.

scholarly journals Method for the Determination of Density and Phase Functions of Interplanetary Dust

1980 ◽  
Vol 90 ◽  
pp. 55-60
Author(s):  
A. Mujica ◽  
G. Lôpez ◽  
F. Sánchez
Keyword(s):  
Light Intensity ◽  
Unit Volume ◽  
Interplanetary Space ◽  
Scattered Light ◽  
Interplanetary Dust ◽  
Scattered Light Intensity ◽  
Zodiacal Light ◽  
Method Of Determination ◽  
Phase Functions

SummaryA method of determination of the scattered light intensity, , by a unit-volume of interplanetary space is presented. From ground base Zodiacal Light measurements and the experimental results of Pioneer X the density, ρ(r), and phase, σ(θ), functions are obtained without any previous assumptions about them.

scholarly journals Particle size distribution of sawdust and wood shavings mixtures

2010 ◽  
Vol 56 (No. 4) ◽  
pp. 154-158 ◽  
Author(s):  
T. Vítěz ◽  
P. Trávníček
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Distribution Function ◽  
Network Analysis ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Mass Fraction ◽  
Particle Sizes ◽  
Wood Shavings ◽  
Number Of Particles

Particle size distribution of the sample of waste sawdust and wood shavings mixtures were made with two commonly used methods of mathematical models by Rosin-Rammler (RR model) and by Gates-Gaudin-Schuhmann (GGS model).On the basis of network analysis distribution function F (d) (mass fraction) and density function f (d) (number of particles captured between two screens) were obtained. Experimental data were evaluated using the RR model and GGS model, both models were compared. Better results were achieved with GGS model, which leads to a more accurate separation of the different particle sizes in order to obtain a better industrial profit of the material.

Effect of a finite number of particles in the Bose-Einstein condensation of a trapped gas

1997 ◽  
Vol 55 (5) ◽  
pp. 3954-3956 ◽  
Author(s):  
R. Napolitano ◽  
J. De Luca ◽  
V. S. Bagnato ◽  
G. C. Marques
Keyword(s):  
Finite Number ◽  
Einstein Condensation ◽  
Bose Einstein Condensation ◽  
Trapped Gas ◽  
Bose Einstein ◽  
Number Of Particles

scholarly journals 4.1 Meteors and Interplanetary Dust

1976 ◽  
Vol 31 ◽  
pp. 359-372 ◽  
Author(s):  
Peter M. Millman
Keyword(s):  
Chemical Composition ◽  
Interplanetary Dust ◽  
Physical Structure ◽  
Cumulative Number ◽  
Mean Size ◽  
The Mean ◽  
A Minor ◽  
Lower Limits ◽  
Lower Mass Limit ◽  
Number Of Particles

AbstractThe contribution of meteor observations to our knowledge of meteoroids and interplanetary dust is reviewed under four headings – flux, mass distribution, physical structure and chemical composition. For lower limits of particle mass ranging from 1 g to 10−5 g the mean cumulative flux into the earth’s atmosphere varies from 2 × 10−15 to 6 × 10−9 particles m−2 s−1 (2Πster)−1, and the mean size distribution of these particles is given by log N = C – 1.3 log M, where N is the cumulative number of particles counted down to a lower mass limit M, and C is a constant. The physical structure of meteoroids in the above range is essentially fragile, with generally low mean bulk densities that tend to increase with decrease in mass. A minor fraction, about 10 or 15 per cent, with orbits lying inside that of Jupiter, have densities several times the average densities, approaching those of the carbonaceous chondrites. The mean chemical composition of meteoroids seems to be similar to the bronzite chondrites for the elements heavier than number 10, but with the probable addition of extra quantities of the light volatiles H, C and O.

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