Tomographic imaging of the angular-dependent coherent-scatter cross section

In this paper, we present a theoretical model of a parametric array for tomographic applications. The array in the model is assumed to extend right up to the receiver and its cross section is assumed not to be negligible. These two assumptions have not been previously made in applications concerned with tomography. We invoke conditions that permit the derivation of a simple relation for tomographic reconstruction of variations in the acoustic nonlinear parameter throughout the cross section of an object.

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Modeling the Forward-Scatter Cross Section of 3-Dimensional Objects by Means of the Shadow Contour Theorem: An Assessment

2018 15th European Radar Conference (EuRAD) ◽

10.23919/eurad.2018.8546577 ◽

2018 ◽

Author(s):

Davide Comite ◽

Marta Tecla Falconi ◽

Alessandro Galli ◽

Frank Silvio Marzano ◽

Pierfrancesco Lombardo

Keyword(s):

Cross Section ◽

Scatter Cross Section ◽

Forward Scatter ◽

3 Dimensional

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Spectral characteristics and scatter cross-section of low latitude mesospheric echoes measured by the Indian MST radar at Gadanki

Annales Geophysicae ◽

10.5194/angeo-30-983-2012 ◽

2012 ◽

Vol 30 (6) ◽

pp. 983-990 ◽

Cited By ~ 3

Author(s):

E. Belova ◽

S. Kirkwood ◽

T. Narayana Rao ◽

S. Satheesh Kumar ◽

T. Sergienko

Keyword(s):

Energy Dissipation ◽

Cross Section ◽

Scatter Cross Section ◽

Spectral Characteristics ◽

Turbulent Energy ◽

Scattering Mechanism ◽

Low Latitude ◽

Special Experiment ◽

Mst Radar ◽

First Time

Abstract. In November 2008 and in March and April 2009 the Indian MST radar (53 MHz) at Gadanki was operated during the daytime in a special experiment, with 600 m altitude resolution, for understanding the characteristics of low-latitude mesospheric echoes (LLME). The data of three days when the echoes were strongest have been analysed in terms of spectral widths and radar volume reflectivities. Spectral widths of LLME show some decrease with altitude, with median values of 4–6 m s−1 at 69–72 km and of 2–4 m s−1 at 73–78 km. This corresponds to 20–200 mW kg−1 turbulent energy dissipation rates. It has been shown that stronger echoes have broader spectra consistent with a turbulent scattering mechanism. For the first time, the volume reflectivities for the strong LLME for Gadanki have also been calculated. They are in the range of 10−17–10−15 m−1, so LLME at Gadanki are somewhat stronger than those reported so far from Jicamarca, Peru (Lehmacher et al., 2009).

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Tomographic Imaging Using Optical Sensor Arrays

Jurnal Teknologi ◽

10.11113/jt.v27.1023 ◽

1997 ◽

pp. 57-60

Author(s):

Ruzairi Abdul Rahim ◽

R.G. Green

Keyword(s):

Cross Section ◽

Optical Sensor ◽

Sensor Arrays ◽

Tomographic Imaging ◽

Solid Particles ◽

Measuring System ◽

Sufficient Data ◽

Optical Fibre Sensor ◽

Image Flow ◽

Fibre Sensor

This paper describes an investigation into the use of an optical fibre sensor to measure the flow of pneumatically conveyed solid particles. The diameter of the fibre sensor is 1mm. A tomographic measuring system constructed from arrays of tran ducer pairs is described, which is capable or capturmg sufficient data and reconstruct an image flow. Two arrangement, orthogonal 8x8 and 16x16 will be discused later and comparisons of resolution made using phantoms in a pipe or 81mm diameter cross-section with a phantom.

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XUV Absorption Spectra of Carbon Ions

International Astronomical Union Colloquium ◽

10.1017/s0252921100107444 ◽

1988 ◽

Vol 102 ◽

pp. 71-73

Author(s):

E. Jannitti ◽

P. Nicolosi ◽

G. Tondello

Keyword(s):

Absorption Spectra ◽

Cross Section ◽

Theoretical Calculations ◽

Photoionization Cross Section ◽

Carbon Ions

AbstractThe photoabsorption spectra of the carbon ions have been obtained by using two laser-produced plasmas. The photoionization cross-section of the CV has been absolutely measured and the value at threshold, σ=(4.7±0.5) × 10−19cm2, as well as its behaviour at higher energies agrees quite well with the theoretical calculations.

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Elastic Scattering in Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071703 ◽

1973 ◽

Vol 31 ◽

pp. 252-253

Author(s):

J. Langmore ◽

M. Isaacson ◽

J. Wall ◽

A. V. Crewe

Keyword(s):

Electron Microscopy ◽

Elastic Scattering ◽

Cross Section ◽

Quantum Noise ◽

Dark Field ◽

Elastic Cross Section ◽

Biological Molecules ◽

Dark Field Microscopy ◽

Field Systems ◽

Effects Of Radiation

High resolution dark field microscopy is becoming an important tool for the investigation of unstained and specifically stained biological molecules. Of primary consideration to the microscopist is the interpretation of image Intensities and the effects of radiation damage to the specimen. Ignoring inelastic scattering, the image intensity is directly related to the collected elastic scattering cross section, σɳ, which is the product of the total elastic cross section, σ and the eficiency of the microscope system at imaging these electrons, η. The number of potentially bond damaging events resulting from the beam exposure required to reduce the effect of quantum noise in the image to a given level is proportional to 1/η. We wish to compare η in three dark field systems.

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A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100073933 ◽

1973 ◽

Vol 31 ◽

pp. 698-699

Author(s):

V. Mizuhira ◽

Y. Futaesaku

Keyword(s):

Cross Section ◽

Tannic Acid ◽

Elastic Fiber ◽

The Other ◽

New Approach ◽

Tissue Block ◽

Active Reaction ◽

The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

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Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010006444x ◽

1971 ◽

Vol 29 ◽

pp. 78-79

Author(s):

J. P. Colson ◽

D. H. Reneker

Keyword(s):

Cross Section ◽

Cross Sections ◽

Detailed Examination ◽

The Other ◽

Electron Micrograph ◽

Irradiation Effects ◽

Threefold Axis ◽

Typical Sample ◽

Polymer Crystals ◽

Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

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