Fractal Description of Extra Terrestrial Fineparticles

Abstract

A technique for measuring the fractal structure of the rugged boundaries exhibited by lunar dust and a cosmic dust fineparticle captured at the outer limits of earth's atmosphere are measured using a equipaced polygon construction measurement procedure. The measurement procedure is described and data illustrating the precision and accuracy of the method are presented. The technique can be automated using inexpensive equipment and is suitable for use in teaching laboratories. Comparative data is presented establishing that the equipaced polygon procedure generates data comparable to that generated by the structured walk exploration technique. It is suggested that the fractal structure of extra terrestrial fineparticles may be of interest not only to the cosmologist but to the mining engineer since lunar dust represents fractured material not subjected to attrition polishing. Models used to simulate the generation of soot in combustion processes are discussed and it is demonstrated that diffusion limited aggregation Monte Carlo routines generate an agglomerate that appears to have similar fractal structure to the cosmic dust fineparticle collected by Brownlee. The data presented also indicates that one should usc caution when relating the fractal dimension of a projected perimeter profile in two dimensions to the three dimensional structure of a rugged fineparticle.

The Effect of Ionic Migration and Diffusion on the Roughness Development of Growing Electrodeposits. The Use of Fractals to Compare Theory With Experimental Results

“…Several other methods for determining the fractal dimension of boundary outlines exist since the scaling properties of fractal structures may be exploited to devise a variety of techniques for determining the Downloaded by [University of Cincinnati Libraries] at 23: 18 20 November 2014 fractal dimension of different structures [14][15][16][17][18][19][20][21]. Fractals have been used to describe a variety of phenomena in physics and chemistry [22][23][24][25][26], whilst in chemical engineering, they have been used to quantify the surface roughness of particles, how this changes during attrition, as well as its effects on mass and momentum transfer [8,[27][28][29][30].…”

What Use are Fractals?

“…One place in the solar system where we can find freshly shattered rock fragments which are not subjected to polishing by erosion of any kind is on the surface of the moon. In the lower part of Figure 3.24, the fractal dimensions of the four lunar fragments as measured by equi- paced polygon logic are shown [44]. In particular, one type of material appeared to be very rugged.…”

“…In Figure 3.24, four of the fragments photographed by Professor Heywood are shown [43]. The fractal dimension of Dr. Brownlee's cosmic dust, as measured at Laurentian University using the equipaced polygon technique, is shown by the side of the cosmic fineparticle [44]. Scoracious is derived from a Greek root word which can be politely translated as "dung-like."…”

“…The ruggedness of scoracious lunar dust fineparticles can be described using fractal dimensions[44].…”

Fractal-based description of urban form

“…The problem with the structured walk method is that, if there are deep fissures in the curve, this can cause perturbations in the Richardson plot through the chord length suddenly falling to the lengths where such detail is picked up. This can then distort the dimension, so an alternative method known as the equipaced polygon method has been suggested by Kaye and Clark (1985). In fact, this method was first implemented by Schwarz and Exner (1980) as an artifact of the particular image analyser used in measuring particle boundaries, and has subsequently been developed by Orford and Whalley (1983).…”