scholarly journals T-matrix determination of effective permittivity for three-dimensional dense random media

2000 ◽  
Vol 48 (2) ◽  
pp. 317-327 ◽  
Author(s):  
P.R. Siqueira ◽  
K. Sarabandi
Keyword(s):  
Random Media ◽  
Effective Permittivity ◽  
Three Dimensional ◽  
T Matrix

LOW ENERGY EXCITATIONS AND NON-ERGODICITY IN THE COULOMB GLASS

1994 ◽  
Vol 08 (07) ◽  
pp. 923-933 ◽  
Author(s):  
M. Ortuño ◽  
M. Pollak ◽  
J. Talamantes
Keyword(s):  
Relaxation Time ◽  
Low Temperatures ◽  
Random Media ◽  
Three Dimensional ◽  
Low Energy ◽  
Zero Temperature ◽  
Correlation Effects ◽  
Interacting Particles ◽  
Coulomb Glass

Recent computational methods permit the determination of the low energy states of fair sized systems of localized interacting particles in random media. Making use of such methods, this paper evaluates the nature of the low-energy excitations of the system, and it’s implications on conductivity and on ergodicity. Two- and three-dimensional systems are examined. It is found that the low energy excitations exhibit strong correlation effects, indicating that one-particle theories for equilibrium and non-equilibrium properties are not justified. Ergodicity is tested by relaxation at zero temperature. It is found that relaxation time can be extremely long, indicating that the system is not ergodic at low temperatures.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

scholarly journals Meso-Scale Transmission Electron Microscope Tomography Applied for Wax Distribution in Toner Particles

2013 ◽  
Vol 19 (S5) ◽  
pp. 58-61 ◽  
Author(s):  
Mino Yang ◽  
Jun-Ho Lee ◽  
Hee-Goo Kim ◽  
Euna Kim ◽  
Young-Nam Kwon ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Three Dimensional ◽  
Chromatic Aberration ◽  
Laser Printer ◽  
Medium Voltage ◽  
Transmission Electron ◽  
Z Contrast ◽  
Contrast Image

AbstractDistribution of wax in laser printer toner was observed using an ultra-high-voltage (UHV) and a medium-voltage transmission electron microscope (TEM). As the radius of the wax spans a hundred to greater than a thousand nanometers, its three-dimensional recognition via TEM requires large depth of focus (DOF) for a volumetric specimen. A tomogram with a series of the captured images would allow the determination of their spatial distribution. In this study, bright-field (BF) images acquired with UHV-TEM at a high tilt angle prevented the construction of the tomogram. Conversely, the Z-contrast images acquired by the medium-voltage TEM produced a successful tomogram. The spatial resolution for both is discussed, illustrating that the image degradation was primarily caused by beam divergence of the Z-contrast image and the combination of DOF and chromatic aberration of the BF image from the UHV-TEM.

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