Optical reflectance of a composite medium with a sparse concentration of large spherical inclusions

2003 ◽  
Vol 240 (3) ◽  
pp. 480-489 ◽  
Author(s):  
A. García-Valenzuela ◽  
R. G. Barrera
Keyword(s):  
Composite Medium ◽  
Optical Reflectance ◽  
Spherical Inclusions ◽  
Large Spherical

On the Maxwell–Garnett model of chiral composites

1993 ◽  
Vol 8 (4) ◽  
pp. 917-922 ◽  
Author(s):  
Akhlesh Lakhtakia ◽  
Vijay K. Varadan ◽  
Vasundara V. Varadan
Keyword(s):  
Multiple Scattering ◽  
Free Space ◽  
Composite Medium ◽  
Spherical Inclusions ◽  
Taylor Expansions ◽  
Chirality Parameter ◽  
Extrinsic Properties

The Maxwell–Garnett model for isotropic chiral spherical inclusions in free space has been briefly reviewed, and pertinent results for the effective intrinsic and extrinsic properties of the composite medium, along with useful Taylor expansions, have been obtained in the Drude–Born–Fedorov representation. It has been shown that this model does not yield the chirality parameter of the composite independently of the permeability and the permittivity, and treats the permeability and the permittivity as duals of each other. Finally, even if the inclusions are nonmagnetic, the composite medium may not be necessarily so. It is anticipated that the formulae derived here will not only assist in the formulation of more rigorous multiple scattering theories, but will also aid designers of chiral composites.

An intraerythrocytic virus and rickettsia of frogs from Algonquin Park, Ontario

1984 ◽  
Vol 62 (8) ◽  
pp. 1521-1524 ◽  
Author(s):  
Sherwin S. Desser ◽  
John R. Barta
Keyword(s):  
Electron Microscope ◽  
Rana Catesbeiana ◽  
Blood Parasites ◽  
Rana Clamitans ◽  
Virus Particles ◽  
Spherical Inclusions ◽  
Sphagnum Bog ◽  
Prokaryotic Microorganisms ◽  
Large Spherical

Two prokaryotic microorganisms were observed in the erythrocytes of frogs in a survey of blood parasites of six species of amphibians from a sphagnum bog adjacent to Lake Sasajewun, Algonquin Park, Ontario. A cytoplasmic virus was observed in 12 of 75 Rana catesbeiana and 1 of 75 Rana septentrionalis. The virus particles were hexagonal in section, measured 300–370 nm in diameter, and occurred in groups that were often surrounded by lamellar arrays of stacked membranes. Large spherical inclusions were seen in the erythrocytes of 2 of 57 Rana clamitans. In the electron microscope these inclusions were found to contain numerous rod-shaped prokaryotes which measured 1–1.7 μm × 200–300 nm. These organisms were ultrastructurally indistinguishable from rickettsiae.

Observation of dislocations in dynamically loaded Cu-SiO2

1986 ◽  
Vol 44 ◽  
pp. 424-425
Author(s):  
D. S. Pritchard
Keyword(s):  
Electron Microscope ◽  
Strain Rate ◽  
Single Crystal ◽  
Transmission Electron Microscope ◽  
Volume Fraction ◽  
Screw Dislocations ◽  
Spherical Inclusions ◽  
Transmission Electron ◽  
Crystal Dispersion ◽  
Strain Rate Loading

The effect of varying the strain rate loading conditions in compression on a copper single crystal dispersion-hardened with SiO2 particles has been examined. These particles appear as small spherical inclusions in the copper lattice and have a volume fraction of 0.6%. The structure of representative crystals was examined prior to any testing on a transmission electron microscope (TEM) to determine the nature of the dislocations initially present in the tested crystals. Only a few scattered edge and screw dislocations were viewed in those specimens.

The microstructure change of low-carbon electrical steels by residual aluminum

1989 ◽  
Vol 47 ◽  
pp. 286-287
Author(s):  
C.K. Hou ◽  
C.T. Hu ◽  
Sanboh Lee
Keyword(s):  
Annealing Treatment ◽  
Low Carbon ◽  
Electrical Steels ◽  
Vacuum Degassing ◽  
Spherical Inclusions ◽  
Residual Aluminum ◽  
Average Grain Size ◽  
The Matrix ◽  
Fine Size ◽  
To Come

The fully processed low-carbon electrical steels are generally fabricated through vacuum degassing to reduce the carbon level and to avoid the need for any further decarburization annealing treatment. This investigation was conducted on eighteen heats of such steels with aluminum content ranging from 0.001% to 0.011% which was believed to come from the addition of ferroalloys.The sizes of all the observed grains are less than 24 μm, and gradually decrease as the content of aluminum is increased from 0.001% to 0.007%. For steels with residual aluminum greater than 0. 007%, the average grain size becomes constant and is about 8.8 μm as shown in Fig. 1. When the aluminum is increased, the observed grains are changed from the uniformly coarse and equiaxial shape to the fine size in the region near surfaces and the elongated shape in the central region. SEM and EDAX analysis of large spherical inclusions in the matrix indicate that silicate is the majority compound when the aluminum propotion is less than 0.003%, then the content of aluminum in compound inclusion increases with that in steel.

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.

scholarly journals Surface Texturing of Si with Periodically Arrayed Oblique Nanopillars to Achieve Antireflection

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 380
Author(s):  
Jun-Hyun Kim ◽  
Sanghyun You ◽  
Chang-Koo Kim
Keyword(s):  
Aspect Ratio ◽  
Plasma Etching ◽  
Surface Texturing ◽  
Light Reflection ◽  
Si Substrate ◽  
Weighted Mean ◽  
Optical Reflectance ◽  
Si Substrates ◽  
Aspect Ratios ◽  
Shadowing Effect

Si surfaces were texturized with periodically arrayed oblique nanopillars using slanted plasma etching, and their optical reflectance was measured. The weighted mean reflectance (Rw) of the nanopillar-arrayed Si substrate decreased monotonically with increasing angles of the nanopillars. This may have resulted from the increase in the aspect ratio of the trenches between the nanopillars at oblique angles due to the shadowing effect. When the aspect ratios of the trenches between the nanopillars at 0° (vertical) and 40° (oblique) were equal, the Rw of the Si substrates arrayed with nanopillars at 40° was lower than that at 0°. This study suggests that surface texturing of Si with oblique nanopillars reduces light reflection compared to using a conventional array of vertical nanopillars.

Dynamic behaviors of pulsed-laser annealing in ion-implanted silicon studied by measuring the optical reflectance

1979 ◽  
Author(s):  
Kouichi Murakami ◽  
Kenji Gamo ◽  
Susumu Namba ◽  
Mitsuo Kawabe ◽  
Yoshinobu Aoyagi ◽  
...  
Keyword(s):  
Laser Annealing ◽  
Pulsed Laser ◽  
Optical Reflectance ◽  
Dynamic Behaviors ◽  
Pulsed Laser Annealing ◽  
Ion Implanted
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