Computation of the internal field of a large spherical particle by use of the geometrical-optics approximation

1997 ◽  
Vol 36 (33) ◽  
pp. 8724 ◽  
Author(s):  
Nadejda Velesco ◽  
Thomas Kaiser ◽  
Gustav Schweiger
Keyword(s):  
Spherical Particle ◽  
Internal Field ◽  
Geometrical Optics ◽  
Large Spherical Particle ◽  
Large Spherical

Internal Distribution of Radiant Absorption in a Spherical Particle

1991 ◽  
Vol 113 (2) ◽  
pp. 407-412 ◽  
Author(s):  
A. Tuntomo ◽  
C. L. Tien ◽  
S. H. Park
Keyword(s):  
Refractive Index ◽  
Electromagnetic Wave ◽  
Spherical Particle ◽  
Complex Refractive Index ◽  
General Pattern ◽  
Wave Theory ◽  
Internal Field ◽  
Geometrical Optics ◽  
Small Spherical Particle ◽  
Internal Distribution

This paper applies electromagnetic wave theory for the study of the internal radiant absorption field of a small spherical particle, particularly to determine the optimum combination of size-to-wavelength parameter and complex refractive index for maximum local peak absorption. A map is devised to illustrate the general pattern of the internal field, which can be divided into three main regimes: uniform, front-concentrated, and back-concentrated absorption. In addition, the current study employs geometrical optics to investigate the internal field of radiant absorption. A comparison between the results from the geometrical optics approach to those from electromagnetic wave theory shows that the error involved in the geometrical optics approach increases sharply with the real part of the complex refractive index. A criterion is established to define the region of the applicability of geometrical optics.

The electrophoretic mobility of large colloidal particles

1981 ◽  
Vol 59 (13) ◽  
pp. 1878-1887 ◽  
Author(s):  
Richard Wyndham O'Brien ◽  
Robert John Hunter
Keyword(s):  
Spherical Particle ◽  
Electrophoretic Mobility ◽  
Double Layer ◽  
Reliable Method ◽  
Colloidal Particles ◽  
Analytical Approximation ◽  
Large Spherical Particle ◽  
Computer Calculations ◽  
Complicated Nature ◽  
Large Spherical

Analytical approximation formulae linking ζ potential and electrophoretic mobility have been derived for a variety of limiting conditions. In this paper we present a simplified derivation of an equation first established by Dukhin and his collaborators for a large spherical particle with a thin double layer. Although potentially a very useful expression it has been little used to date, partly because of the complicated nature of Dukhin's derivation and partly because of the lack of a reliable method of testing its validity. The expression compares very favourably with the computer calculations of O'Brien and White, provided κa is sufficiently large.

Electron-diffraction studies of amorphous carbon thin films

1993 ◽  
Vol 51 ◽  
pp. 1100-1101
Author(s):  
David A. Muller
Keyword(s):  
Thin Films ◽  
Electron Diffraction ◽  
Amorphous Carbon ◽  
Glassy Carbon ◽  
Spherical Structure ◽  
Local Ordering ◽  
Carbon Arc ◽  
Similar Appearance ◽  
Carbon Thin Films ◽  
Large Spherical

The sp2 rich amorphous carbons have a wide variety of microstructures ranging from flat sheetlike structures such as glassy carbon to highly curved materials having similar local ordering to the fullerenes. These differences are most apparent in the region of the graphite (0002) reflection of the energy filtered diffracted intensity obtained from these materials (Fig. 1). All these materials consist mainly of threefold coordinated atoms. This accounts for their similar appearance above 0.8 Å-1. The fullerene curves (b,c) show a string of peaks at distance scales corresponding to the packing of the large spherical and oblate molecules. The beam damaged C60 (c) shows an evolution to the sp2 amorphous carbons as the spherical structure is destroyed although the (220) reflection in fee fcc at 0.2 Å-1 does not disappear completely. This 0.2 Å-1 peak is present in the 1960 data of Kakinoki et. al. who grew films in a carbon arc under conditions similar to those needed to form fullerene rich soots.

Thermal Buoyancy-Aided Flow around a Heated/Cooled Spherical Particle

2011 ◽  
Vol 42 (8) ◽  
pp. 689-710 ◽  
Author(s):  
P. P. Gopmandal ◽  
Somnath Bhattacharyya
Keyword(s):  
Spherical Particle ◽  
Thermal Buoyancy
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